FISH OIL

FISH OIL:

There is considerable evidence that fish and fish oils are beneficial to heart health, reduce the risk of cancer, and benefit mental health. The "active" components of fish oils are eicosapentaenoic acid (EPA), a polyunsaturated fatty acid with 20 carbon atoms in its backbone, and docosahexaenoic acid (DHA), a polyunsaturated fatty acid with 22 carbon atoms. Both are members of the omega-3 group of essential fatty acids. EPA and DHA are found exclusively in marine animals; fatty fish such as herring, sardines, salmon and fresh tuna are the best sources.
Alpha-linolenic acid (ALA) is another omega-3 fatty acid found in flaxseed and flaxseed oil. ALA has 18 carbon atoms in its backbone and can be converted to EPA in the body (in the liver) by the addition of two carbon atoms. EPA, in turn, can be converted to DHA. Because the typical American diet is relatively low in fish intake ALA becomes a crucial source of the EPA and DHA required for optimum health.
Researchers at the National Institutes of Health have just completed a study designed to determine just how much ALA is actually converted to EPA in the body. Their study included eight healthy subjects who were fed a standard diet for three weeks and then given one gram of ALA labeled with an isotope tracer. The diet was beef-based in order to avoid extraneous sources of EPA and DHA. The researchers measured blood plasma concentrations of ALA, EPA and DHA 8, 24, 48, 72, 96 and 168 hours after ingestion of the labeled ALA.
The results show that only about 0.2 per cent of the ALA (2 mg) was actually converted to EPA. In contrast, about 23 per cent of the EPA was available for conversion to DHA. The researchers also noted that the half-life (the time it takes to reduce initial concentration by 50 per cent) of ALA in blood plasma was quite low at about one hour. In comparison, the half-life of EPA was 67 hours and that of DHA 20 hours.
The researchers conclude that ALA is not a viable source of EPA and DHA and cannot replace fish and fish oils in the diet. Editor's Note: According to this new data a tablespoon of flax oil would only result in the synthesis of about 30 mg of EPA – far less than the recommended daily intake of 220 mg.
Pawlosky, Robert J. Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans. Journal of Lipid Research, Vol. 42, August 2001, pp. 1257-65

Polyunsaturated fatty acids are safe
OSLO, NORWAY. Polyunsaturated fatty acids (PUFAs) of the n-6 and n-3 configurations cannot be synthesized by humans and must be obtained from the diet. The most common PUFAs are linoleic acid, linolenic acid, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oils. Linoleic acid is an n-6 configuration while linolenic acid, EPA and DHA are of the n-3 configuration. Because of the unsaturated nature (multiple double bonds) of PUFAs they are prone to oxidation which makes them rancid and potential initiators of chain reactions which can lead to oxidation of fat and cholesterol molecules in the body. This so-called lipid peroxidation reaction is believed to be implicated in atherosclerosis, cancer and inflammation.

Dr. Jan Eritsland, a cardiologist at the Ulleval University Hospital, has just released a major study dealing with the safety of n-3 and n-6 PUFAs. Based on numerous reports published in the medical literature Dr. Eritsland concludes that a high intake of n-3 PUFAs reduces the risk for cardiovascular disease and heart attack and is entirely safe at least up to a level corresponding to 10% of the daily calorie intake. He does caution though that the intake of dietary antioxidants (especially vitamin E) needs to be increased if the PUFA intake is increased. Supplementation with 4 grams/day of highly concentrated fish oil (containing 3.4 g of EPA and DHA) was found to lower triglyceride levels, but had no effect on cholesterol levels or glycemic control (plasma glucose and insulin levels). Although fish oils are known to reduce the tendency of blood to aggregate (clot) a recent major trial showed no difference in bleeding episodes among heart disease patients supplementing with 2 to 5 grams/day of fish oils and the controls. This held true even if the patients were also taking warfarin or aspirin. PUFAs of the n-3 family may help prevent cancer and there is no evidence at all that they promote it.
Eritsland, Jan. Safety considerations of polyunsaturated fatty acids. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 197S-201S

Fish oils are vital to your health
PORTLAND, OREGON. Research carried out over the past 20 years has clearly shown that omega-3 fatty acids such as DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) are essential elements in human nutrition. The primary source of DHA and EPA is fatty fish and oils from the tissues of such fish. DHA is a vital component of the phospholipids in cell membranes throughout the body, but is particularly abundant in the brain, retina, and sperm. Fish oils either from whole fish or in the form of supplements have been found to aid in preventing or ameliorating coronary heart disease, stroke, lupus, nephropathy (kidney disorders), Crohn's disease, breast cancer, prostate cancer, colon cancer, hypertension, and rheumatoid arthritis. Fish oils have been found particularly effective in preventing arrhythmias and sudden death from cardiac arrest. Several studies have shown that people who eat fish once or more each week can reduce their risk of sudden cardiac death by 50-70 per cent. EPA has been found to inhibit blood clotting and EPA and DHA contained in fish oils inhibit the development of atherosclerosis. Fish oil supplementation also significantly lowers overall triglyceride and cholesterol levels without affecting the level of HDL ("good" cholesterol).

Recent research has shown that the consumption of high fat meals can initiate the development of atherosclerotic deposits. This effect can be substantially reduced by taking fish oil prior to eating such meals. Omega-3 fatty acids are essential to fetal development and a deficiency of DHA during gestation can lead to visual impairment and perhaps, lower intelligence quotients.

In summary, omega-3 fatty acids and in particular, DHA and EPA from fish oils, are essential for human development and in the prevention and amelioration of many common disorders. [38 references]
Connor, William E. Importance of n-3 fatty acids in health and disease. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 171S-75S

Benefits of essential fatty acids
HONOLULU, HAWAII. Dr. Joseph Pepping, a consulting pharmacist at the Kaiser Permanente, provides a comprehensive review of the many benefits of omega-3 fatty acids and their derivatives. He cites evidence that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) which are found in fish oils are helpful in the prevention and treatment of cardiovascular disease, arrhythmias, diabetes, breast cancer, and arthritis. While EPA is readily synthesized in the body from alpha-linolenic acid (found in flaxseed oil) Dr. Pepping states that the synthesis of DHA is much more difficult and that DHA must be obtained directly from fish, certain algae or green, leafy vegetables. He also points out that the body's optimal balance between omega-6 (linoleic) and omega-3 (linolenic) fatty acids is a 2:1 to 4:1 ratio. Unfortunately, the typical Western diet contains these acids in ratios of 20:1 to 25:1. An excess of omega-6 fatty acids can lead to formation of blood clots, allergic and inflammatory disorders, and the accelerated growth of certain cancer cells. Dr. Pepping recommends two servings of cold-water fish (e.g. salmon, mackerel or herring) per week, 2-4 grams of fish oil capsules per day or 15-30 ml of flaxseed oil per day as a preventive measure. He points out that it is important to add 200 IU of vitamin E to the daily diet if supplementing with fish oils. He also advises caution regarding fish oil supplementation in patients taking warfarin, heparin, low-molecular weight heparin, ticlopidine or clopidogrel.
Pepping, Joseph. Omega-3 essential fatty acids. American Journal of Health-System Pharmacy, Vol. 56, April 15, 1999, pp. 719-24

Your brain needs DHA
NEW YORK, NY. Dr. Barbara Levine, Professor of Nutrition in Medicine at Cornell University, sounds the alarm concerning a totally inadequate intake of DHA (docosahexaenoic acid) by most Americans. DHA is the building block of human brain tissue and is particularly abundant in the grey matter of the brain and the retina. Low levels of DHA have recently been associated with depression, memory loss, dementia, and visual problems. DHA is particularly important for fetuses and infants; the DHA content of the infant's brain triples during the first three months of life. Optimal levels of DHA are therefore crucial for pregnant and lactating mothers. Unfortunately, the average DHA content of breast milk in the United States is the lowest in the world, most likely because Americans eat comparatively little fish. Making matters worse is the fact that the United States is the only country in the world where infant formulas are not fortified with DHA. This despite a 1995 recommendation by the World Health Organization that all baby formulas should provide 40 mg of DHA per kilogram of infant body weight. Dr. Levine believes that postpartum depression, attention deficit hyperactivity disorder (ADHD), and low IQs are all linked to the dismally low DHA intake common in the United States. Dr. Levine also points out that low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. DHA is abundant in marine phytoplankton and cold-water fish and nutritionists now recommend that people consume two to three servings of fish every week to maintain DHA levels. If this is not possible, Dr. Levine suggests supplementing with 100 mg/day of DHA.
Levine, Barbara S. Most frequently asked questions about DHA. Nutrition Today, Vol. 32, November/December 1997, pp. 248-49

Health benefits of fish oils
SANTIAGO, CHILE. Fish oils are excellent sources of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). EPA and DHA in turn are important components of cell membranes and as such play a vital role in overall health. Studies have shown that Greenland Eskimos, who have a very high intake of fish oils, have a very low incidence of heart attacks, asthma, diabetes, psoriasis, and allergies. A Dutch study found that middle-aged men who ate as little as 30 grams of fish per day (average) reduced heart disease mortality by 50 per cent. A study at the Harvard Medical School concluded that men who eat fish have a 26 per cent lower risk of death from coronary artery disease than men who do not eat fish. Other studies have shown that an adequate DHA supply is essential for normal eye and brain development in infants and children. Fish oils are found in high concentrations in herrings, sardines and anchovies, in medium concentrations in salmon, and in somewhat lower concentrations in sole, halibut, cod and shellfish. Fish oils have demonstrable benefits in the prevention and treatment of cardiovascular disease; they reduce blood pressure and triglycerides, modify platelet aggregation, and minimize inflammatory responses. There is anecdotal evidence that fish oils may be beneficial in the treatment of migraine headaches, asthma, and psoriasis. Cell membranes rich in polyunsaturated fatty acids such as EPA and DHA are, however, more susceptible to peroxidation by free radical reactions. This may severely affect their structure and function unless precautions are taken to ensure that the free radicals are neutralized by lipid-soluble antioxidants. Research has shown that people taking fish oil supplements also need to increase their intake of vitamin E.
Uauy-Dagach, Ricardo and Valenzuela, Alfonso. Marine oils: the health benefits of n-3 fatty acids. Nutrition Reviews, Vol. 54, November 1996, pp. S102-S108

Role of fish oils in health and disease
WASHINGTON, DC. Dr. Artemis Simopoulos of the Center for Genetics, Nutrition and Health has just released a major, ground-breaking study concerning fish oils and their role in human health. Dr. Simopoulos' 25-page report contains 211 references and is truly a gold mine of information about omega- 3 fatty acids and in particular the polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish oils.

Dr. Simopoulos points out that omega-3 polyunsaturated fatty acids (PUFAs) are essential for human health, but that their intake has gradually declined over the years. It is believed that man evolved on a diet with a ratio of omega-6 to omega-3 PUFAs of about 1:1. Today this ratio is more like 10:1 and in some societies is approaching 25:1. A relative over-abundance of omega-6 PUFAs has been implicated in excessive blood clotting, allergic and inflammatory disorders, and certain cancers. An adequate intake of omega-3 PUFAs, on the other hand, has been linked to improved cardiovascular health. A recent study concluded that a daily intake of 500 to 1000 mg of long chain omega-3 PUFAs reduces the risk of cardiovascular death in middle-aged American men by about 40%. Other studies have shown that although fish oils help prevent undesirable blood clotting reactions they do not increase bleeding time and are quite safe even for people scheduled for major surgery. Animal studies have found that fish oil supplementation markedly reduces the risk of fatal arrhythmias. Fish oils have also been found beneficial in preventing or treating hypertension, arthritis, psoriasis, ulcerative colitis, cancer, and certain diabetes- related complications. EPA and DHA are both essential for pregnant mothers and infants and a deficiency can retard the development of the brain and retina.

It is estimated that the optimal daily intake of EPA and DHA (total) is about 300 to 400 mg/day. The current average intake in the United States is only 50 mg EPA and 80 mg DHA per person per day indicating a massive deficiency in the American diet. Dr. Simopoulos points out that the Canadian Ministry of Health's guidelines for fatty acid intake recommends a daily intake of 1000 to 1800 mg of omega-3 PUFAs. She cautions that fish oil supplements should always be stabilized with adequate amounts of vitamin E in order to prevent oxidation leading to rancidity. [211 references]
Simopoulos, Artemis. Omega-3 fatty acids in health and disease and in growth and development. American Journal of Clinical Nutrition, Vol. 54, 1991, pp. 438-63

Fish oils protect women against heart disease
BOSTON, MASSACHUSETTS. There is ample evidence that frequent fish consumption or supplementation with fish oils markedly reduces the risk of coronary heart disease, sudden cardiac death, and heart attacks in men. Up until now there has been little work done to see if the same holds true for women. Researchers at the Harvard Public School of Health have just released the results of a major study aimed at remedying this situation.
The study involved 84,688 female nurses who were enrolled in 1970. All participants completed food frequency questionnaires in 1980, 1984, 1986, 1990 and 1994. In the 16-year period between 1980 and 1996 a total of 1513 women either died from coronary heart disease (484) or suffered a non-fatal heart attack (1029). After adjusting for age, smoking and other known cardiovascular risk factors the researchers conclude that women who eat fish once a week have a 34 per cent lower incidence of death from heart disease and a 25 per cent lower incidence of non-fatal heart attacks. They also conclude that the protective effect of fish consumption is entirely due to the content of omega-3 fatty acids (fish oils) in the fish. They also note that both fish and fish oil consumption were associated with a decreased risk of dying from any cause. The researchers believe that fish oils reduce the incidence of heart disease through their antiarrhythmic effects and their reduction of platelet aggregability and triglyceride levels. They conclude that their findings lend further support to the benefits of twice weekly fish consumption.
Hu, Frank B., et al. Fish and omega-3 fatty acid intake and risk of coronary heart disease in women. Journal of the American Medical Association, Vol. 287, April 10, 2002, pp. 1815-21

Fish oils protect against sudden death
BOSTON, MASSACHUSETTS. Sudden cardiac death kills about 250,000 Americans every year and half of them have no known cardiovascular disease when they are suddenly struck down. Researchers at Brigham and Women's Hospital and the Harvard School of Public Health now report that men with a high intake of oils from fatty fish (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) have an 81 per cent lower risk of sudden cardiac death than do men with a low intake. Their study involved a group of 15,000 male physicians aged 40 to 82 years when they enrolled in the study. Over a 17-year follow-up period 94 men with no known cardiovascular disease died suddenly from heart failure (sudden cardiac death). Blood samples taken from the men at enrollment were analyzed for fatty acids and the results compared to those obtained from 184 controls. The average age of both controls and cases was 58 years.
The researchers found that men whose blood levels of EPA and DHA constituted 6.87 per cent or more of their total fatty acid concentration had an 81 per cent lower risk of sudden cardiac death than did men whose level was 3.58 per cent or less. This correlation remained after adjusting for confounding factors such as diabetes, hypertension, exercise, aspirin usage, cholesterol levels, alcohol consumption, etc. The researchers conclude that their findings support the hypothesis that fish oils (EPA and DHA) are responsible for the inverse association between fish consumption and sudden death.
Dr. Irwin Rosenberg, MD of Tufts University comments that the study is further proof that striving for a daily intake of 1 gram per day of fish oils (from fatty fish) helps protect against sudden cardiac death.
Albert, Christine M., et al. Blood levels of long-chain n-3 fatty acids and the risk of sudden death. New England Journal of Medicine, Vol. 346, April 11, 2002, pp. 1113-18
Rosenberg, Irwin H. Fish: food to calm the heart. New England Journal of Medicine, Vol. 346, April 11, 2002, pp. 1102-03

Trans-fatty acids implicated in sudden death
SEATTLE, WASHINGTON. Almost two thirds of deaths from heart disease are sudden and almost half of all heart disease deaths occur before the patient reaches the hospital. What is perhaps even more disturbing is that 50 per cent of people dying suddenly from cardiac arrest never knew they had a heart problem. It is clear that finding the cause(s) of sudden cardiac death is a high priority. Researchers at the University of Washington now report that high levels of trans-fatty acids are strongly associated with an increased risk of sudden cardiac death.
Their study involved 179 sudden death victims between the ages of 25 and 74 years and 285 age- and sex-matched controls. Both cases and controls had blood samples drawn and analyzed for fatty acid levels in red blood cell membranes. The researchers found that cardiac arrest victims tended to have significantly higher overall levels of trans-fatty acids than did the controls. Specifically, they had higher levels of 18:1 (oleic) and 18:2 (linoleic) trans-fatty acids and significantly lower levels of beneficial long chain omega-3 fatty acids (EPA and DHA). After adjusting for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and other factors which could affect heart disease risk they concluded that people with a high 18:2 (linoleic) trans-fatty acid level had a three times higher risk of sudden cardiac death than did people with lower levels. High levels of 18:1 (oleic) trans-fatty acids were not associated with increased risk. Linoleic trans-fatty acids are formed when vegetable oils are partially hydrogenated or used for frying and are also found in beef and chicken. Commercially prepared pizza and cookies are other potent sources of 18:2 acids.
Lemaitre, Rozenn N., et al. Cell membrane trans-fatty acids and the risk of primary cardiac arrest. Circulation, Vol. 105, February 12, 2002, pp. 697-701
Katz, Arnold M. Trans-fatty acids and sudden cardiac death. Circulation, Vol. 105, February 12, 2002, pp. 669-71 (editorial)

New risk factor for sudden death
PARIS, FRANCE. Sudden cardiac death is a common occurrence in industrialized countries. There is evidence that a high level of free fatty acids in the blood plasma is an independent risk factor for ventricular arrhythmias and sudden death in people who have suffered a heart attack. Medical researchers at the University of Paris now report that a high level of circulating free fatty acids (non- esterified) is also a potent risk factor for sudden death in men without cardiovascular disease.
The study involved 5250 men, aged 42 to 53 years at the start of the study in 1967-72. All participants were free of cardiovascular disease at the time of entry. The men were followed for an average of 22 years during which 1601 deaths occurred – 91 of them were classified as sudden cardiac deaths and 145 as fatal heart attacks. Analysis of test data showed that the level of free fatty acids circulating in the blood plasma is a potent risk factor for sudden death. Men with a high level had a 70 per cent higher risk than did men with a low level. Surprisingly, high fatty acid levels were not a risk factor for fatal heart attack. Other prominent risk factors for sudden death were parental sudden death, parental heart attack, smoking, high systolic blood pressure, and high body mass index (obesity). High cholesterol levels increased the risk of sudden death by a relatively modest 18 per cent.
The researchers and Dr. Alexander Leaf, MD of the Harvard Medical School point out that not all fatty acids are detrimental. There is ample evidence that the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main components of fish oil are actually highly protective against sudden cardiac death. Dr. Leaf believes that it is the omega-6 fatty acids found in vegetable oils (corn, safflower, sunflower, and peanut) that are responsible for initiating the arrhythmias leading to sudden death. Fish oils, on the other hand, exert a protective effect in amounts as low as 600-1000 mg/day (EPA+DHA). Dr. Leaf points out that government agencies and heart associations have long been advocating an increased intake of polyunsaturated fatty acids without making any distinction between omega-6 essential fatty acids which appear to promote sudden death and omega-3 fatty acids (EPA and DHA) which prevent it.
Jouven, Xavier, et al. Circulating nonesterified fatty acid level as a predictive risk factor for sudden death in the population. Circulation, Vol. 104, August 14, 2001, pp. 756-61
Leaf, Alexander. Plasma nonesterified fatty acid concentration as a risk factor for sudden cardiac death: the Paris prospective study. Circulation, Vol. 104, August 14, 2001, pp. 744-45 (editorial)

Fish oils prevent sudden cardiac death
AALBORG, DENMARK. Sudden cardiac death is the most common cause of death in Western countries and accounts for about 50% of all deaths from heart disease. In other words, 50% of all people with heart disease have their condition "diagnosed" by suddenly dying form it. It is clear that anything that might help to prevent sudden cardiac death (SCD) would be of immense benefit. Several clinical trials have concluded that eating fish regularly or supplementing with fish oils can reduce the risk of SCD by as much as 50%. Other studies have found that wine drinking also has a protective effect.

Danish researchers now report that fish oils markedly increase heart rate variability and conclude that this is probably the explanation for their protective effect. Their study involved 291 patients who had been referred for coronary angiography because of suspected heart disease. The participants completed food questionnaires including a question about wine consumption and had their blood cell (granulocytes) and fat tissue level of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) determined. The participants also had their heart rate variability (HRV) measured over a 24-hour period.

The researchers found an excellent correlation between the reported intake of fish and fat tissue levels of EPA and DHA. They also noted a distinct association between high EPA/DHA levels and high HRV. Patients with a high wine intake also had high HRV values, but further analysis showed that these patients also had a high fish intake. When corrected for this confounding variable there was no correlation between wine consumption and HRV. There also was no correlation between the intake of beer and HRV.

The researchers conclude that high body levels of EPA and DHA can markedly reduce the risk of sudden cardiac death and ascribe this protective effect to the increased heart rate variability associated with increased fish or fish oil consumption.
Christensen, Jeppe Hagstrup, et al. Marine n-3 fatty acids, wine intake, and heart rate variability in patients referred for coronary angiography. Circulation, Vol. 103, February 6, 2001, pp. 651-57
Bigger, J. Thomas and El-Sherif, Tarek. Polyunsaturated fatty acids and cardiovascular events: a fish tale. Circulation, Vol. 103, February 6, 2001, pp. 623-25 (editorial)

Increased fish intake combats heart disease
DALLAS, TEXAS. The American Heart Association (AHA) has just released its most recent guidelines for reducing the risk of cardiovascular disease by dietary and other lifestyle practices. The AHA clearly endorses the consumption of fish or fish oils as a means of preventing and treating heart disease. The guidelines point to the growing body of evidence indicating that foods rich in omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), provide significant protection against heart disease. Among the benefits of EPA and DHA, the main components of fish oils, are:

Lower risk of arrhythmias
A reduction in the risk of sudden cardiac death
Lower plasma triglyceride levels
Reduced blood clotting tendency

The guidelines recommend that the current intake of omega-3 fatty acids be increased and specifically recommend at least 2 servings of fish per week. The AHA is even more enthusiastic about fish oils when it comes to protecting patients with existing heart disease against further deterioration or death. They refer to numerous studies which have found that supplementing with 850 mg to 2.9 grams/day of fish oils is highly beneficial for heart disease patients. A recent large-scale trial found that patients with coronary heart disease who supplemented with 850 mg/day of EPA plus DHA reduced their risk of sudden death by 45% and their overall risk of death by 20%. The AHA guidelines conclude that "Consumption of 1 fatty fish meal per day (or alternatively, a fish oil supplement) could result in an omega-3 fatty acid intake (i.e. EPA and DHA) of about 900 mg/day, an amount shown to beneficially affect coronary heart disease mortality rates in patients with coronary disease."

Other major AHA guidelines for heart disease prevention are:

Eliminate smoking and moderate intake of sugar, salt, alcohol, trans-fatty acids, saturated fatty acids, and cholesterol
Increase intake of fruits, vegetables and whole grains
Match energy (food) intake to energy needs so as to maintain a healthy body weight
Exercise more and spend less time on watching television and other sedentary activities.

Krauss, Ronald M., et al. AHA Dietary Guidelines - Revision 2000: a statement for healthcare professionals from the Nutrition Committee of the American Heart Association. Circulation, Vol. 102, October 31, 2000, pp. 2284-99

Fish consumption reduces heart disease risk
LISBON, PORTUGAL. Several studies have concluded that consumption of fish and fish oils reduces the risk of coronary artery disease. Researchers at the University of Lisbon now add further weight to this conclusion through their publication of a study designed to evaluate the differences in heart disease between a fishing village and an inland rural village on the island of Madeira. The mortality rate from heart disease in Camara de Lobos (the fishing village) was 310/100,000 men during the period 1990 to 1997 as compared to 1205/100,000 men in Curral (the rural village).

Fifty men (aged 25 to 65 years) from the fishing village and 37 men from the rural village participated in the study. They all had fasting blood samples drawn and had their food intake evaluated by 2 nutritionists using a food frequency questionnaire. The men from the fishing village consumed 8 times more fish than did the men in the rural village and as a result had much higher levels of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in their blood than did the men in the rural village. The researchers observed a good correlation between fish intake and blood levels of EPA and DHA. They also found that the fishing village men had lower levels of triglycerides (28% lower) and total cholesterol (10% lower) than did the men from the inland village. Of particular note was the finding that the ratio of EPA to arachidonic acid in the blood was twice as high in the fishing village as in the rural village. A high ratio has, in other studies, been linked to a lower incidence of blood clots.

The researchers conclude that regular fish consumption is associated with higher blood levels of EPA and DHA, lower triglyceride and cholesterol levels, and a 4 times lower mortality from coronary heart disease.
Torres, Isabel C., et al. Study of the effects of dietary fish intake on serum lipids and lipoproteins in two populations with different dietary habits. British Journal of Nutrition, Vol. 83, 2000, pp. 371-79

The ultimate supplement for heart health
KANSAS CITY, MISSOURI. Researchers at the Mid America Heart Institute have come out strongly in favor of routine fish or fish oil supplementation for heart patients and people at risk for heart disease. The researchers summarize the results of a large number of clinical trials which have clearly shown that fish oil supplementation or increased fish consumption can reduce the risk of dying from heart disease by 20- 50% or more. They believe that fish oils (eicosapentaenoic acid and docosahexaenoic acid) exert their protective effect by preventing fatal ventricular arrhythmias, by increasing heart rate variability, decreasing fibrinogen and platelet counts (important in preventing blood clotting) and by reducing blood pressure. A recent trial found that fish oils are highly effective in reducing ventricular premature complexes (missed heart beats) and they have also been found to counteract the arrhythmia-inducing properties of eicosanoids derived from arachidonic acid. The US Food and Drug Administration recently reviewed the safety profile of EPA and DHA and concludes that a combined daily intake of these two essential fatty acids of up to 3 grams per day is safe. The Heart Institute researchers point out that fish oils are effective in relatively small doses (approximately 1 gram/day) and have no adverse interactions with other heart drugs. They conclude "After 25 years of research, we believe that sufficient evidence is now available to recommend not only fish for cardiac patients, but also specifically EPA and DHA."
O'Keefe, Jr., James H. and Harris, William S. Omega-3 fatty acids: time for clinical implementation? American Journal of Cardiology, Vol. 85, May 15, 2000, pp. 1239-41
O'Keefe, Jr., James H. and Harris, William S. From Inuit to implementation: omega-3 fatty acids come of age. Mayo Clinic Proceedings, Vol. 75, June 2000, pp. 607-14 [85 references]

Fish consumption and coronary heart disease
BILTHOVEN, THE NETHERLANDS. Several studies have found a correlation between fish consumption and death from coronary heart disease (CHD). By far the majority of the studies concluded that fish consumption reduces the risk of dying from CHD, but a few found no such effect and one even found a negative effect. A team of researchers from Finland, Italy, and the Netherlands believes they have found the reason for the differing results.

Their study involved 2738 men who were aged 50 to 69 years at the start of the study in 1970. After 20 years of follow-up 242 (22.2%) of the Finnish men, 116 (10.6%) of the Italian men, and 105 (19%) of the Dutch men had died from CHD. The researchers found no correlation between total fish consumption and CHD mortality. They also failed to confirm a correlation between the consumption of lean fish (plaice, codfish, bream, perch, pike) and the risk of dying from CHD. However, when looking at the consumption of fatty fish (mackerel, herring, eel) the researchers found a clear protective effect. Men who habitually consumed fatty fish had a 34% lower risk of dying from CHD than did men who did not eat fatty fish. This correlation held true even after adjusting for other variables commonly associated with an increased risk of death from CHD.

The researchers point out that while 15 grams of lean fish provides only about 50 mg of omega-3 fatty acids, 15 grams of fatty fish provides about 400 mg. They suggest that the oils in fatty fish (eicosapentaenoic acid and docosahexaenoic acid) prevent death from CHD through their inhibition of platelet aggregation, their antiarrhythmic properties, and their tendency to increase heart rate variability. The researchers believe that the reason why one study found a higher mortality from CHD among Finnish men consuming lean fish was that the fish from the area under study was heavily contaminated with mercury.
Oomen, Claudia M., et al. Fish consumption and coronary heart disease mortality in Finland, Italy, and the Netherlands. American Journal of Epidemiology, Vol. 151, May 15, 2000, pp. 999-1006

Eat fish and live longer
BOSTON, MASSACHUSETTS. There is a growing consensus that regular fish consumption protects against heart disease. There is, however, still controversy as to whether this protection applies to all forms of heart disease and it is also not clear how fish exerts its protective effect. Some studies have found that fish consumption protects only against sudden cardiac death while others have found that it protects only against nonsudden death. Now researchers at the Harvard Medical School and the Brigham and Women's Hospital weigh in with a comprehensive new study which concludes that even modest fish and shellfish consumption protects against sudden cardiac death in men and significantly reduces total mortality. The study involved over 20,000 male American physicians who were between the ages of 40 and 84 years in 1982 when the study commenced. Food frequency questionnaires were administered after 12 and 18 months and again in 1988. By December 1995 133 of the participants had died from a sudden cardiac event (death occurring within one hour from onset of symptoms). Analysis of the collected data showed that the men who consumed fish once or more each week had a 52 per cent lower risk of dying from a sudden cardiac event than did the men who ate fish less than once a month. This lower risk applied after adjusting for all other known risk factors. The estimated dietary intake of marine n-3 fatty acids also correlated well with the risk of sudden cardiac death with an intake of more than 300 mg/month providing significant protection. The extent of protection did not increase significantly with greater fish or marine n-3 fatty acid intake indicating that eating fish once a week is sufficient to provide worthwhile protection.

Fish consumption was not associated with the risk of nonsudden death, total myocardial infarction or total deaths from cardiovascular diseases. There was, however, a 30 per cent decrease in the overall mortality among the men consuming fish once or more each week as compared to the men eating fish less than once per month. The researchers speculate that fish consumption may exert its protective effect by preventing fatal arrhythmias. They suggest that the n-3 fatty acids found in fish and shellfish (eicosapentaenoic acid and docosahexaenoic acid) are responsible for the antiarrhythmic properties and point out that alpha-linolenic acid, an n-3 fatty acid found in flax oil and nuts, also has antiarrhythmic properties. They did not investigate the benefits of fish oil supplements and purposely excluded 777 physicians from the study who were taking fish oil supplements. The researchers conclude that eating fish once per week may substantially reduce the risk of sudden cardiac death. In an accompanying editorial Dr. Daan Kromhout of the Dutch National Institute of Public Health concurs with this conclusion and adds that patients already suffering from cardiac disease should be advised to eat fish twice a week.
Albert, Christine M., et al. Fish consumption and risk of sudden cardiac death. Journal of the American Medical Association, Vol. 279, January 7, 1998, pp. 23-28
Kromhout, Daan. Fish consumption and sudden cardiac death. Journal of the American Medical Association, Vol. 279, January 7, 1998, pp. 65-66 (editorial)

Vegetable oils don't affect beneficial effects of fish oils
BATON ROUGE, LOUISIANA. Unsaturated fatty acids from fish and fish oils (eicosapentaenoic acid and docosahexaenoic acid) are highly effective in preventing death from cardiovascular disease. Fish oils have strong antiarrhythmic properties and help prevent death from ventricular fibrillation; they also help prevent blood clotting and lower cholesterol and triglyceride levels.

Fish oils (n-3 polyunsaturated fatty acids) and n-6 polyunsaturated fatty acids (from vegetable oils) are metabolized in a similar way and n-3 polyunsaturated fatty acids (n-3 PUFAs) have been shown to block the conversion of linoleic acid, the major n-6 PUFA in vegetable oils, to arachidonic acid. These interactions and competitive metabolic pathways have raised concerns that the benefits of fish oil consumption may be reduced if the diet is high in n-6 PUFAs from vegetable oils.

Researchers at the Louisiana State University have just released the results of a major study aimed at addressing these concerns. Their study involved 68 healthy men and women between the ages of 18 and 49 years. The participants consumed diets containing varying amounts of fish oils and vegetable oils for an eight-week period. The researchers found that fish oil supplementation lowered the blood plasma levels of triglycerides and arachidonic acid independent of the level of n-6 PUFAs in the diet. They conclude that vegetable oil in the diet does not reduce the benefits of fish oil in lowering the risk of death from heart disease. They also conclude that the fish oil intake required to effectively reduce triglyceride levels is less than six grams/day and that higher intakes do not confer added benefits. The daily intake required to affect a meaningful reduction in fibrinogen concentration (an indicator of blood clotting tendency) is less clear; it may be as low as 1.3 grams/day or as high as 15 grams/day. Further work is required to settle this question. [30 references]
Hwang, Daniel H., et al. Does vegetable oil attenuate the beneficial effects of fish oil in reducing risk factors for cardiovascular disease? American Journal of Clinical Nutrition, Vol. 66, July 1997, pp. 89-96
Connor, William E. Do the n-3 fatty acids from fish prevent deaths from cardiovascular disease? American Journal of Clinical Nutrition, Vol. 66, July 1997, pp. 188-89 (editorial)

Omega-3 fatty acids help protect against heart disease
SAN FRANCISCO, CALIFORNIA. Researchers at the Veterans Affairs Medical Center report that docosapentaenoic acid and docosahexaenoic acid (a main component of fish oil) provide significant protection against the development of coronary heart disease (CHD). Their study involved over 6,000 middle-aged men who had samples of their blood taken between 1973 and 1976. During the next seven years, 94 of these men had a heart attack or died suddenly due to heart disease. The 94 men were matched with 94 healthy men and the fatty acid profile of their blood samples compared. The researchers found that the 94 men with heart disease tended to have a higher serum level of the saturated fatty acid palmitic acid and conclude that a high level of this acid increases the risk of CHD by 68 per cent. Palmitic acid is the main saturated fatty acid in most diets. This acid is known to cause an increase in both total cholesterol and low-density cholesterol levels; the researchers, however, found that the detrimental effect of a high intake of palmitic acid persisted even after allowing for its cholesterol- increasing effect. The researchers also determined that men with a higher blood level of the omega-3 unsaturated fatty acids, docosapentaenoic acid and docosahexaenoic acid had an almost 50 per cent lower risk of developing heart disease than did men with lower levels. The researchers also found that men with CHD tended to have a higher serum level of omega-6 fatty acids derived from linoleic acid, but were unable to confirm previous reports that these acids are linked to an increased risk of CHD.
Simon, Joel A., et al. Serum fatty acids and the risk of coronary heart disease. American Journal of Epidemiology, Vol. 142, No. 5, September 1, 1995, pp. 469-76

Docosahexaenoic acid fights depression
ROCKVILLE, MARYLAND. Researchers at the National Institute of Alcohol Abuse and Alcoholism believe that the increasing rates of depression seen in North America over the last 100 years are due to a significant shift in the ratio of n-6 (arachidonic acid, linoleic acid) to n-3 (docosahexaenoic acid, linolenic acid) fatty acids in the diet. The human race evolved on a diet having a ratio of about 1:1 of these acids; it is now estimated to be between 10:1 and 25:1. Docosahexaenoic acid (DHA) is a main component of the synaptic membranes and a lack of it has been linked to depression. Fish oils are a rich source of DHA and it can also be biosynthesized in the body from linolenic acid. The researchers speculate that the depressions which often accompany alcoholism, multiple sclerosis, and childbirth (postpartum depression) are all due to a lack of DHA and can be corrected by increasing the dietary intake of DHA or linolenic acid (flax seed oil). They also point out that depression and coronary heart disease are strongly associated and that a low intake of n-3 fatty acids has been linked to both.
Hibbeln, Joseph R. and Salem, Norman. Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. American Journal of Clinical Nutrition, Vol. 62, July 1995, pp. 1-9

Fish is good for you
TROMSO, NORWAY. Norwegian researchers now offer conclusive evidence that eating fish, particularly fatty fish like mackerel, herring, and salmon will significantly reduce the risk of heart disease. As little as one serving of 300 gram per week will provide the benefit. Fish are rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and it is these polyunsaturated fatty acids which provide protection. It is suggested that the minimal dietary requirement for EPA and DHA should be about 200 mg/day and this amount can be obtained from eating fish once a week.
Nordoy, Arne. Is there a rational use for n-3 fatty acids (fish oils) in clinical medicine? DRUGS, Vol. 42, No. 3, 1991, pp. 331-42

Consuming freshwater fish may lower risk of heart disease
KUOPIO, FINLAND. A 15-week experiment involving 62 students was carried out to determine if a regular diet of freshwater fish affects coronary heart disease risk factors. The students were divided into three groups: a fish eating group who made no other changes to their diet, a fish eating group who also decreased their overall fat intake and a control group (19 students) who ate a typical western diet. The special diet consisted of one fish meal a day (in addition to the regular diet) and provided about 0.25 g/day of eicosapentaenoic acid and 0.55 g/day of docosahexaenoic acid. Serum cholesterol was found to decrease in fish eaters who also decreased their lipid intake but not in the other groups. Blood triglyceride levels decreased significantly in the fish eating groups, but not in the control group. Levels of apolipoproteins A1 and B were lowered in both fish eating groups as was the formation of thromboxane B2 during incubation of whole blood. In the fish eating groups, the proportion of omega-3 fatty acids increased significantly in erythrocyte ghosts and platelets at the expense of omega-6 fatty acids. The results of the study support the contention that moderate fish consumption has a protective effect against coronary heart disease.
Agren, J.J., et al. Boreal freshwater fish diet modifies the plasma lipids and prostanoids and membrane fatty acids in man. LIPIDS, Vol. 23, No.10, October 1988, pp. 924-29

Fish oils: a must for heart attack survivors
SANTA MARIA IMBARO, ITALY. A group of Italian researchers (GISSI) reported in 1999 that supplementation with fish oil reduces the mortality among patients who have survived a first heart attack. Their study involved over 11,000 heart attack survivors who supplemented with 1 gram/day of fish oil (580 mg of eicosapentaenoic acid [EPA] and 290 mg of docosahexaenoic acid [DHA]) for 3.5 years.
The researchers have now re-analyzed their data in an attempt to determine how the fish oil exerts its protective effect. The reduced mortality was apparent after only three months of supplementation (1.1 per cent versus 1.6 per cent in the placebo group) and continued for the duration of the study. The reduction in the incidence of sudden cardiac death accounted for about 57 per cent of the total improvement in mortality rates. At the end of the study 2.7 per cent of the placebo group participants had died from sudden cardiac death as compared to only 2.0 per cent in the fish oil group. Overall, cardiovascular death (including stroke) at the end of the study was 6.5 per cent in the placebo group versus 5.5 per cent in the fish oil group. There was no statistical significant difference in the incidence of non-fatal heart attacks between the fish oil and placebo groups.
The researchers conclude that fish oils exert their protective effect by preventing fatal ventricular arrhythmias rather than through an improvement in cholesterol profile. They did note a small (4.6 per cent) drop in triglyceride levels in the fish oil group, but found no significant differences in LDL (low- density lipoprotein) and HDL (high-density lipoprotein) cholesterol between the two groups. They also point out that the number of lives (per 1000 patients) which could be saved every year by giving heart attack survivors fish oil exceeds the number of lives (per 1000 patients) estimated to be saved by treating heart disease patients with high cholesterol levels with pravastatin. This puts fish oils squarely in the category of highly effective heart "drugs".
Marchioli, Roberto, et al. Efficacy of n-3 polyunsaturated fatty acids after myocardial infarction: results of GISSI-Prevenzione trial. Lipids, Vol. 36, Supplement 2001, pp. S119-S126
Marchioli, Roberto, et al. Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of GISSI-Prevenzione. Circulation, Vol. 105, April 23, 2002, pp. 1897-1903
Leaf, Alexander. On the reanalysis of the GISSI-Prevenzione. Circulation, Vol. 105, April 23, 2002, pp. 1874-75 (editorial)

Fish oils and heart disease
AALBORG, DENMARK. It is increasingly clear that atherosclerosis is, at least partially, an inflammatory disease. There is also growing evidence that high blood levels of C-reactive protein (CRP) are associated with an increased risk of coronary heart disease and heart attacks. Danish researchers now report a direct correlation between CRP levels and severity of atherosclerosis. They also suggest that CRP levels can be kept in check by frequent consumption of fish or fish oils. Their study involved 269 patients referred for angiography because of suspected coronary artery disease. Besides undergoing angiography the patients had their CRP levels measured and were also tested for the level of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in their granulocytes (a type of white blood cell). They also filled out a questionnaire about their fish consumption.
The researchers found that patients with one or more coronary arteries blocked by 50 per cent or more had significantly higher CRP levels in their blood than had patients with no significant blockages. They also observed an inverse correlation between CRP levels and the level of DHA in granulocytes. The level of DHA in granulocytes, in turn, was closely related to fish consumption. The researchers conclude that DHA has an anti-inflammatory effect which results in lower CRP levels and suggest that fish consumption may decrease the risk of coronary artery disease.
Madsen, Trine, et al. C-reactive protein, dietary n-3 fatty acids, and the extent of coronary artery disease. American Journal of Cardiology, Vol. 88, November 15, 2001, pp. 1139-42

Fish oils prevent stroke in women
BOSTON, MASSACHUSETTS. A 1995 study concluded that men who ate fish five or more times per week had a 40 per cent lower risk of having a stroke than did men who ate fish less than once a week. Researchers at the Harvard Medical School and the Brigham and Women's Hospital now report that the benefits of fish consumption are even more spectacular for women.

Their just completed study involved 79,839 female nurses who were between the ages of 34 and 59 years at the start of the study in 1980. After 14 years of follow-up a total of 574 strokes had occurred in the group. Most of the strokes (303) were ischemic, i.e. caused by a blood clot. There were also 181 hemorrhagic strokes, i.e. caused by a ruptured artery and 90 strokes of undetermined origin.

After adjusting for age, smoking and other cardiovascular risk factors the researchers concluded that women who ate fish once a week lowered their risk of having a stroke of any kind by 22 per cent and those who consumed fish five or more times per week reduced their risk by 52 per cent. They ascribe the protective effect of fish consumption to the commensurate intake of fish oils (omega-3 fatty acids). They estimate that women whose intake of fish oils is 0.5 gram/day or more have a 30 per cent lower risk of suffering a stroke than do women whose intake is below about 0.1 gram/day. There was no evidence that women with a high fish or fish oil consumption have an increased risk of hemorrhagic stroke. The researchers believe that the protective effects of fish oils are due to their ability to inhibit platelet aggregation, lower blood viscosity, suppress the formation of leukotrienes, reduce fibrinogen levels and reduce blood pressure levels and insulin resistance. They also note that the beneficial effects of fish consumption were substantially more pronounced among women who did not take aspirin on a regular basis.
Iso, Hiroyasu, et al. Intake of fish and omega-3 fatty acids and risk of stroke in women. Journal of the American Medical Association, Vol. 285, January 17, 2001, pp. 304-12 [40 references]

Fish oils prevent heart attacks
KUOPIO, FINLAND. Finnish researchers provide additional evidence of the protective effects of fish oils. Their recently completed study involved 1871 Finnish men aged 42 to 60 years who were free of coronary heart disease at the beginning of the study in 1984. Ten years later 194 of the men had suffered an acute coronary event (160 heart attacks among them). The men had their blood analyzed for fatty acids at the start of the study. Men with a high level (more than 3.58% of total fatty acids) of the polyunsaturated fatty acids found in fatty fish, docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA), were found to have a 44% lower risk of suffering an acute coronary event than did men with a low level (less than 2.38% of total fatty acids). There was no correlation between the level of eicosapentaenoic acid (EPA) and heart attack risk.

Fish caught in Finnish waters tends to have a high level of mercury so the researchers also measured the hair content of mercury in the study participants. They found that men with a high DHA+DPA level and a low mercury level (less than 2 micrograms/gram) had a 67% lower risk of a coronary event than did men with a low DHA+DPA level and a high mercury content (greater than 2.0 micrograms/gram). The researchers speculate that mercury may contribute to the risk of coronary events by binding selenium in an inactive form so that it cannot support the synthesis of the important antioxidant glutathione peroxidase. They conclude that fish oils reduce the risk of acute coronary events, but caution that mercury in fish could reduce this protective effect. Editor's Note: The best way to avoid mercury and still obtain the benefits of fish oils is by supplementing with a high quality fish oil (molecular distilled).
Rissanen, Tiina, et al. Fish oil-derived fatty acids, docosahexaenoic acid and docosapentaenoic acid, and the risk of acute coronary events. Circulation, Vol. 102, November 28, 2000, pp. 2677-79

Bypass patients may benefit from fish oils
MUNICH, GERMANY. There is considerable evidence that supplementation with fish oils helps prevent or slow down atherosclerosis. Some studies have shown that fish oil supplementation may help prevent restenosis (reclosing) of the arteries after angioplasty, but more recent studies have found no such effect. A recent study found that coronary bypass patients who supplemented their diet with 4 grams/day of an 83% fish oil concentrate had less reclosings (distal anastomosis occlusions) of their bypass grafts than did the controls. After one year the patients taking fish oils had a reclosing (occlusion) rate of 27% while the control patients had a reclosing rate of 33% (a 23% relative improvement).

Eating fatty fish once or more each week or supplementing with fish oils (0.5 g/day) has been found to increase the survival of heart attack patients by 29%. A recent experiment showed that cardiac transplant patients who supplemented with 5 grams/day of fish oils after their operation had normal endothelium- dependent coronary vasodilation when tested after three weeks whereas it was abnormal in matched control patients. It is not known whether fish oil supplementation will increase the survival time for heart transplant patients. [34 references]
von Schacky, Clemens. n-3 fatty acids and the prevention of coronary atherosclerosis. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. S224-27S

Fish oils help prevent sudden cardiac death
AALBORG, DENMARK. Sudden cardiac death (SCD) is now the most common cause of death in the Western world. SCD is often caused by ventricular arrhythmias in patients with heart disease, but may also occur among previously healthy people. The risks of arrhythmias and SCD are closely tied in with heart rate variability (HRV) with a high variability index corresponding to a lower risk. It would also appear that the risk of SCD can be substantially reduced by an increased consumption of fish. Some very recent research has shown that survivors of a first heart attack can avoid having a second one by supplementing with fish oils. An obvious question is whether there is a connection between heart rate variability and fish oil intake.

Danish researchers at the Aalborg Hospital are convinced that there is indeed a very close connection - at least in men. Their recently released study involved 25 women and 35 men who were generally healthy and took no medications. The participants were randomized into three groups. Group 1 was given 10 fish oil capsules daily providing a total of 6.6 grams of n-3 polyunsaturated fatty acids (3.0 g eicosapentaenoic acid [EPA] and 2.9 g docosahexaenoic acid [DHA]); group 2 was given three fish oil capsules (0.9 g EPA and 0.8 g DHA) plus seven olive oil capsules daily, and group 3, the control group, was given 10 olive oil capsules daily. The study participants gave fasting blood samples and had their HRV measured with a Holter recorder for 24 hours at the start of the study and after 12 weeks of supplementation.

The researchers found that fish oil supplementation significantly increased the concentration of EPA and DHA in both blood platelets and granulocytes and that this increase was highly dose-dependent. They also found a significant, dose-dependent reduction in triacylglycerols, but no significant changes in total, LDL or HDL cholesterol levels. The 24-hour Holter recordings showed a correlation between heart rate (pulse rate) and blood level of EPA and DHA with a higher level corresponding to a lower pulse rate in both men and women. There was also a very significant association between DHA level in men and SDNN. SDNN (the standard deviation of all normal R-R intervals during the 24-hr Holter recording) is an important index of HRV with higher values indicating greater heart rate variability. The researchers conclude that supplementation with fish oils, especially DHA, may help prevent arrhythmias and sudden cardiac death in healthy men. They found no association between EPA/DHA levels in women and HRV, but urge further studies to confirm this seeming lack of effect.
Christensen, Jeppe Hagstrup, et al. Heart rate variability and fatty acid content of blood cell membranes: a dose-response study with n-3 fatty acids. American Journal of Clinical Nutrition, Vol. 70, September 1999, pp. 331-37

Fish oils protect against death from heart disease
SANTA MARIA IMBARO, ITALY. There is clear evidence that a diet rich in oily fish confers considerable protection against heart disease. What is less clear is whether concentrated fish tissue oils in capsule form confer similar benefits. A very large group of Italian researchers (Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico) has just completed a major study which shows the benefits of fish oil supplementation in patients who have survived a first heart attack. Their study involved over 11,000 heart attack survivors who were randomly assigned to one of four groups. Group one received a one- gram gelatin capsule containing about 580 mg of eicosapentaenoic acid (EPA) and 290 mg of docosahexaenoic acid (DHA) as ethyl esters every day. Group two received 300 mg of synthetic vitamin E daily; group three both fish oil and vitamin E; and group four served as the control group. All participants ate a largely Mediterranean diet and continued to take their prescribed medications (beta- blockers, aspirin, and ACE-inhibitors). After 3.5 years of follow-up it was clear that the participants who had received fish oil or fish oil plus vitamin E had lowered their risk of dying or having another heart attack or a stroke by 10 to 15 per cent. The group who had taken vitamin E alone derived no statistically significant benefit from doing so. (Editor's note: The 300 mg of synthetic vitamin E used in the study corresponds to about 150 IU of natural vitamin E. This would be much less effective than the 200-400 IU/day of natural vitamin E used in studies which have shown a benefit of vitamin E in regard to heart disease and stroke). The researchers conclude that daily supplementation with fish oils (equivalent of consuming 100 grams of fish per day) is beneficial for patients who have survived a first heart attack. They suggest that the role of vitamin E needs further exploration. (Editor's note: Other studies have shown that vitamin E protects fish oils from going rancid so it is a good idea to take a combination of the two). NOTE: This study was funded in part by Bristol-Myers Squibb, Pharmacia-Upjohn, Societa Prodotti Antibiotici, and Pfizer.
Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. The Lancet, Vol. 354, August 7, 1999, pp. 447-55
Brown, Morris. Do vitamin E and fish oil protect against ischaemic heart disease? The Lancet, Vol. 354, August 7, 1999, pp. 441-42 (commentary)

Fish oils and heart attack
OSLO, NORWAY. There is now substantial evidence that fish and fish oil consumption protects against sudden death from coronary heart disease. There is also evidence that fish consumption reduces the risk of dying from a heart attack (acute myocardial infarction). Researchers at the University of Oslo now report that heart attack patients who had supplemented with cod liver oil (providing approximately 950 mg of eicosapentaenoic acid and 800 mg of docosahexaenoic acid per day) or fish oil capsules (providing approximately 700-1100 mg of eicosapentaenoic acid and 500-750 mg of docosahexaenoic acid per day) for at least 4 weeks prior to their attack tended to have substantially milder attacks than did patients who did not supplement.

The study involved 753 patients who were admitted to hospital with a heart attack and discharged alive. The researchers found that patients who had taken cod liver oil or fish oil tended to have smaller infarcts (small localized areas of dead tissue resulting from a disruption of the blood supply to the areas) than did non-supplementing patients. The researchers conclude that fish oils may reduce infarct size and the incidence of large (more debilitating) infarcts and also seem to enhance the effect of thrombolysis (the dissolution of blood clots by the infusion of an enzyme such as streptokinase). NOTE: This study was supported in part by Zeneca AS, Pfizer AS, Astra Norge AS and Pharmacia AS.
Landmark, Knud, et al. Use of fish oils appears to reduce infarct size as estimated from peak creatine kinase and lactate dehydrogenase activities. Cardiology, Vol. 89, 1998, pp. 94-102 [68 references]

Eating fish prevents death of heart attack patients
AALBORG, DENMARK. A low degree of heart rate variability (HRV) is a very strong predictor of sudden death among survivors of a heart attack (myocardial infarction). Danish researchers now report that a high fish consumption increases the concentration of n-3 polyunsaturated fatty acids (PUFAs) in cell membranes and that this increase is associated with a significant beneficial increase in HRV. Their study involved 52 patients who had suffered a heart attack and had a left ventricular ejection fraction of 40 per cent or less. The researchers found that patients who ate fish once a week had an 18 per cent higher HRV than non-fish eaters. Fish eaters were also found to have a higher content of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) in their blood platelets. Patients with more than 3.14 per cent DHA in their platelets were found to have a 43 per cent higher HRV than patients with a DHA content of less than 2.26 per cent. The researchers also discovered that a high ratio of arachidonic acid to DHA in the platelets corresponds to a significantly lower HRV. Other research has shown that the consumption of just one fatty fish meal per week reduces the risk of primary cardiac arrest by 50 per cent.
Hagstrup Christensen, Jeppe, et al. Fish consumption, n-3 fatty acids in cell membranes, and heart rate variability in survivors of myocardial infarction with left ventricular dysfunction. American Journal of Cardiology, Vol. 79, June 15, 1997, pp. 1670-73

Fish consumption protects against fatal heart attacks
CHICAGO, ILLINOIS. Researchers at the Northwestern University Medical School have just released the results of a 30-year study which shows that eating fish regularly protects against the risk of dying from a heart attack (myocardial infarction). The study involved 1822 men aged 40 to 55 years at the start of the study in 1957. During the 30-year follow-up 1042 men died, 293 of them from a heart attack. Sixty-eight per cent of the study participants were blue-collar workers, 58 per cent were smokers, and 85 per cent drank alcohol. After adjusting for all other variables known to affect the risk of heart disease and heart attack in particular, the researchers found that men who consumed about one kg (two lbs) of fish per month had a 40 per cent lower rate of death from heart attacks than did men who did not eat fish. Men who ate only 500 g (one lb) of fish per month also had a significantly lower risk of a fatal heart attack. The difference in mortality was almost exclusively due to the much lower rate of non-sudden death from heart attack amongst the high fish consumers. The researchers found no significant relationship between fish consumption and death from other cardiovascular causes; they did, however, confirm that cholesterol level, cigarette smoking, dietary cholesterol intake, and age were all independently related to the risk of incurring a fatal heart attack.
Daviglus, Martha L., et al. Fish consumption and the 30-year risk of fatal myocardial infarction. New England Journal of Medicine, Vol. 336, April 10, 1997, pp. 1046-53

Fish oils protect against after-effects of heart attacks
MORADABAD, INDIA. A group of Indian and Iranian medical researchers reports that fish oil supplementation initiated within 18 hours of a heart attack (myocardial infarction) markedly reduces subsequent mortality and after-effects. The double-blind, randomized, placebo-controlled clinical trial involved 360 patients with suspected myocardial infarction. The patients were randomized to receive either fish oil capsules (2 capsules three times daily providing a total of 1.08 g/day of eicosapentaenoic acid and 0.72 g/day of docosahexaenoic acid), mustard oil capsules (providing 2.9 g/day of alpha- linolenic acid) or placebo capsules within 18 hours of experiencing the first symptoms. Supplementation was continued for a full year. The benefits of the fish oil supplementation became apparent within the first 10 days of supplementation. After 10 days 4 of the patients in the fish oil group had suffered a fatal heart attack compared to 6 in the mustard oil group and 6 in the placebo group. There were 6 non-fatal heart attacks in both the placebo and mustard oil groups, but only 1 in the fish oil group. At the end of the 1- year trial 22% of the patients in the placebo group had died from a cardiac event as compared to only 11.4% in the fish oil group. The incidence of non-fatal heart attacks was significantly lower in the fish oil and mustard oil groups (13% and 15% respectively) as compared to the placebo group (25.4%). The fish oil and mustard oil groups also showed a significant reduction in angina attacks, arrhythmias, and left ventricular enlargement as compared to the placebo group. The researchers conclude that fish oil and mustard oil may provide rapid protection in patients who have suffered a heart attack. They urge larger studies to confirm this. NOTE: The researchers make the observation that experimental studies have shown that the intake of 3-4 g/day of alpha-linolenic acid is equivalent to the intake of 0.3 g/day of eicosapentaenoic acid in its effect on the eicosapentaenoic acid content of plasma phospholipids.
Singh, Ram B., et al. Randomized, double-blind, placebo-controlled trial of fish oil and mustard oil in patients with suspected acute myocardial infarction: the Indian experiment of infarct survival. Cardiovascular Drugs and Therapy, Vol. 11, 1997, pp. 485-91

Fish oils protect against arrhythmias
AALBORG, DENMARK. Research has shown that heart attack survivors who increase their intake of oily fish considerably improve their chance of long-term survival. Now Danish researchers report that daily supplementation with fish oil capsules may have a similar effect. Their experiment involved 49 patients who had been discharged from hospital after suffering a heart attack. The study participants were randomly allocated to receive 5 grams per day of fish oil as a mixture of eicosapentaenoic acid and docosahexaenoic acid or a similar amount of olive oil as a placebo for a 12-week period. A 24-hour recording (Holter) of their heart rate was obtained at the start and end of the study. At the end of the experiment the patients in the fish oil group exhibited a marked increase in the variability of their heart rate as compared to the controls. It is believed that greater heart rate variability is desirable in heart attack patients as it protects the heart against often fatal ventricular arrhythmias. The researchers conclude that fish oils may have an antiarrhythmic effect which could account for the better survival among heart attack patients who increase their intake of them.
Christensen, Jeppe Hagstrup, et al. Effect of fish oil on heart rate variability in survivors of myocardial infarction. British Medical Journal, Vol. 312, March 16, 1996, pp. 677-78

Fish oils help prevent cardiac arrest
SEATTLE, WASHINGTON. Cardiac arrest is a serious, usually fatal condition in which the heart stops pumping. Cardiac arrest most commonly occurs in connection with ventricular fibrillation and its primary cause is a heart attack. Researchers at the University of Washington now report that the risk of cardiac arrest can be significantly lowered by an increased intake of seafood rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Their study involved 334 patients who had suffered cardiac arrest during the period 1988 to 1994 and 493 controls matched for age and sex. None of the study participants had had any indication of heart disease prior to the beginning of the study. Interviews with survivors or their spouses were used to determine the participant's fish intake in the month preceding the cardiac arrest. The researchers found that the intake of just one portion of fatty fish per week lowered the risk of cardiac arrest by an impressive 50 per cent after adjusting for age, smoking, family history of heart attacks, hypertension, diabetes, obesity, physical activity, education, and cholesterol level.

The researchers believe that consumption of fish increases the level of EPA and DHA in the membranes of the red blood cells which in turn reduces platelet aggregation and coronary spasm. This belief was confirmed by finding that blood samples taken from 95 cardiac arrest patients and 133 controls showed that a high blood content of EPA and DHA (five per cent of total fatty acids) corresponded to a 70 per cent reduction in the risk of cardiac arrest when compared to study participants with a low EPA and DHA content in their blood (3.3 per cent of total fatty acids). Other studies have shown that patients who have already suffered a heart attack can reduce their risk of future life-threatening arrhythmias and sudden cardiac death by increasing their intake of fish, fish oils or linolenic acid (flax seed oil). The researchers conclude that a modest intake of EPA and DHA from seafood may reduce the risk of ventricular fibrillation and death from coronary heart disease. NOTE: Fresh salmon is one of the best sources of fish oils; it contains twice as much per serving as does albacore tuna and six times more EPA and DHA than a serving of cod.
Siscovick, David S., et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Journal of the American Medical Association, Vol. 274, No. 17, November 1, 1995, pp. 1363-67

Fish oils benefit angina patients
ATHENS GREECE. A team of British and Greek medical researchers report that fish oil supplementation is highly beneficial for angina patients. Their study involved 39 patients (37 men and 2 women) with stable angina pectoris who had experienced at least 6 angina attacks in the 2 weeks prior to the start of the trial. The patients were randomly assigned to receive either 10 grams of fish oil (providing 1.8 g eicosapentaenoic acid and 1.2 g docosahexaenoic acid) every day or 10 grams of olive oil daily. The daily supplements were supplied in the form of 5 identical looking capsules. The trial lasted for a total of 12 weeks and the patients were evaluated at baseline and after 8 and 12 weeks of supplementation.

By the end of the 12 weeks the number of weekly angina attacks had decreased by 41% in the fish oil group with no change observed in the olive oil group. The use of nitroglycerin (glyceryl trinitrate) tablets decreased by 38% in the fish oil group and also decreased slightly (not statistically significant) in the olive oil group. Exercise tolerance, as measured on a treadmill, increased by 22.6% in the fish oil group, but no change was observed in the olive oil group. The blood level (fasting) of triglycerides decreased by 22% eight weeks into the test in the fish oil group, but then tended to approach pre-trial levels again by the 12th week. No statistically significant changes in blood coagulation parameters were observed in either group. The researchers conclude that low-dose fish oil supplementation may benefit patients with coronary artery disease.
Salachas, Anastasios, et al. Effects of low-dose fish oil concentrate on angina, exercise tolerance time, serum triglycerides, and platelet function. Angiology, Vol. 45, December 1994, pp. 1023-31

Fish oils reverse atherosclerosis
MUNICH, GERMANY. German medical researchers have just released the results of a major study which proves that fish oil supplementation is highly beneficial to patients suffering from atherosclerosis. Their randomized, double-blind, placebo-controlled clinical trial involved 162 patients with confirmed atherosclerosis. Half the patients were given six grams of fish oils per day for three months while the other half were given six grams per day of placebo capsules containing a fatty acid composition resembling that of the average European diet. After three months the dosages were reduced to three grams/day for a further 21 months. Angiograms were taken at the start of the trial and at the end of the two-year study period. At the end of the treatment twice as many of the patients in the fish oil group (16) showed regression of their atherosclerotic deposits when compared to the placebo group. Three patients in the placebo group suffered a non-fatal heart attack during the 2-year period as compared to only one in the fish oil group. All told there were seven patients in the placebo group who had a cardiovascular event (heart attack or stroke) as compared to only two in the fish oil group. The researchers conclude that fish oil supplementation is beneficial for atherosclerosis patients and is safe and well-tolerated. NOTE: This study was partially funded by Pronova A.S., a Norwegian fish oil producer.
von Schacky, Clemens, et al. The effect of dietary omega-3 fatty acids on coronary atherosclerosis. Annals of Internal Medicine, Vol. 130, April 6, 1999, pp. 554-62

Garlic and fish oils lower cholesterol
GUELPH, CANADA. Elevated levels of total cholesterol and low-density-lipoprotein (LDL) cholesterol are well established risk factors for coronary heart disease. It is also clear that people with accompanying high levels of triglycerides (triacylglycerol) face an even higher risk of heart disease. Very recent work has shown that high triglyceride levels alone are powerful risk factors for atherosclerosis and heart disease especially among women. Supplementation with garlic has been shown to lower overall cholesterol levels and LDL levels significantly while fish oil supplementation is known to lower triglyceride levels. Unfortunately, fish oil supplementation has also been found to increase LDL levels, a highly undesirable effect.

Now researchers at the University of Guelph report that a combination of garlic and fish oil is highly effective in lowering the levels of total cholesterol, LDL cholesterol, and triglycerides. Their study involved 50 men with a total cholesterol level in excess of 5.2 mmol/L (200 mg/dL). The men were randomly allocated into four groups for the 12-week long experiment. Group 1 was given a daily supplement of 900 mg garlic placebo and 12 g oil placebo, Group 2 took 900 mg garlic (Kwai) and 12 g oil placebo, Group 3 took 900 mg garlic placebo and 12 g fish oil [12 1-gram capsules each containing 180 mg EPA (eicosapentaenoic acid) and 120 mg DHA (docosahexaenoic acid)] while Group 4 took 900 mg garlic and 12 g fish oil per day. All supplements were taken in three divided doses with meals. At the end of the 12- week study period significant reductions were observed for total cholesterol (12.2 per cent), LDL cholesterol (9.5 per cent), and triacylglycerol (34.3 per cent) in the group taking both garlic and fish oil supplements. A significant, reduction (beneficial) in the ratios of total cholesterol to high-density- lipoprotein (HDL) cholesterol and LDL to HDL was also observed for both the garlic groups (with and without fish oil). Garlic by itself did not lower triglyceride concentrations while fish oils by themselves actually increased LDL concentrations significantly (by 8.5 per cent). The researchers conclude that supplementing with garlic pills and fish oils in combination is effective in lowering blood levels of total cholesterol, LDL cholesterol, and triglycerides while at the same time providing a beneficial decrease in the ratios of total cholesterol to HDL cholesterol and in LDL to HDL cholesterol.
Adler, Adam J. and Holub, Bruce J. Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. American Journal of Clinical Nutrition, Vol. 65, February 1997, pp. 445-50
Kris-Etherton, Penny M., et al. Efficacy of multiple dietary therapies in reducing cardiovascular disease risk factors. American Journal of Clinical Nutrition, Vol. 65, February 1997, pp. 560-1 (editorial)

Fish oils fight atherosclerosis
COPENHAGEN, DENMARK. Medical doctors at two Copenhagen hospitals have confirmed that regular consumption of fish prevents narrowing of the arteries due to atherosclerosis. The doctors performed 40 autopsies and determined that the degree of atherosclerosis present in the coronary arteries was inversely proportional to the amount of docosahexaenoic acid found in the adipose (fatty) tissue. They conclude that fish consumption reduces the risk of coronary heart disease.
Seidelin, Kaj N., et al. n-3 fatty acids in adipose tissue and coronary artery disease are inversely related. American Journal of Clinical Nutrition, Vol. 55, June 1992, pp. 1117-19

Fish oil supplementation and risk of atherosclerosis
KANSAS CITY, KANSAS. Short-term trials have concluded that fish oil supplementation has a favourable effect on several risk factors for atherosclerosis. Researchers at the University of Kansas Medical Center report the results of a 6-month study designed to determine the effect of fish oil supplementation at various dosages on cholesterol levels, triglyceride levels, bleeding time, and blood (plasma phospholipids) levels of fatty acids. The trial involved 28 patients who had high (average 275 mg/dL) cholesterol levels and high (average 337 mg/dL) triglyceride levels. The patients were randomly assigned to receive 3, 6, 9 or 12 fish oil capsules daily for six months. Three capsules provided 1.25 grams of long-chain (20-22 carbon) omega-3 fatty acids. All trial variables were measured twice before supplementation began and then at the end of 1, 5, and 6 months of supplementation as well as after one month of washout at the conclusion of the trial.

There was no statistically significant changes in total cholesterol level among any of the groups. Triglyceride levels decreased by an overall 30% with higher fish oil intakes providing greater decreases. Low-density cholesterol (LDL) levels and high-density cholesterol (HDL) levels both increased by an overall 7% during the six-month supplementation period thus maintaining the important LDL/HDL ratio. There was no clear overall correlation between fish oil doses and bleeding time, but patients taking 6 or 12 capsules did appear to have significantly longer bleeding times. Both linoleic and arachidonic acid levels in phospholipids were reduced by all doses of fish oil. Levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) rose significantly as dosages increased. All measured variables tended to converge towards baseline values after the final one-month washout period. The researchers conclude that fish oil supplementation produces physiologically important changes which may lower the risk of cardiovascular disease. NOTE: This study was supported in part by Warner-Lambert a manufacturer of pharmaceuticals.
Harris, William S., et al. Effects of four doses of n-3 fatty acids given to hyperlipidemic patients for six months. Journal of the American College of Nutrition, Vol. 10, No. 3, 1991, pp. 220-27

The brain-heart connection
NORWOOD, MASSACHUSETTS. Dr. U.N. Das, MD of EFA Sciences LLC provides a fascinating overview of the many benefits of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the main components of fish oils. Dr. Das points out that an excess of tumor necrosis factor alpha (TNF) is involved in not only coronary heart disease, but also in many inflammatory diseases such as ulcerative colitis, Crohn's disease, rheumatoid arthritis, systemic lupus erythematosus, and septic shock. An increased intake of fish oils suppresses TNF production – a possible explanation for their beneficial effects. EPA and DHA also have a direct effect on the central nervous system. It is suggested that they increase brain levels of acetylcholine and activate the parasympathetic branch of the autonomous nervous system. This in turn leads to increased heart rate variability and a commensurate reduction in the risk of ventricular arrhythmias and sudden cardiac death. Dr. Das points out that the effect of fish oils in this respect is very similar to those obtained by exercise. EPA and DHA also act directly on individual heart muscle cells (myocytes) to suppress their tendency to go into spontaneous arrhythmia. Dr. Das emphasizes that it is important to ensure the availability of adequate amounts of arachidonic acid and dihomo-gamma-linolenic acid in the diet in order to obtain the full benefits of fish oils as preventers of arrhythmias. He also makes the intriguing observation that EPA and DHA can block the entry of sodium and calcium ions into vascular smooth muscle cells; this may be another mechanism by which fish oils help prevent ventricular arrhythmias and sudden cardiac death. Finally, Dr. Das points out that different individuals may need different doses of EPA/DHA in order to achieve their heart protective effect. [143 references]
Das, U.N. Beneficial effect(s) of n-3 fatty acids in cardiovascular diseases: but, why and how? Prostaglandins, Leukotrienes and Essential Fatty Acids, Vol. 63, December 2000, pp. 351-62

Omega-3 fatty acids: the missing link?
BERLIN, GERMANY. Dr. Emanuel Severus of the Berlin University points out that major depression is characterized by a deficiency of omega-3 fatty acids and that these acids possess powerful antiarrhythmic properties. He suggests that the missing link in the recently established association between major depression and sudden cardiac death may be the omega-3 fatty acid deficiency which characterizes both conditions.
Severus, W. Emanuel, et al. Omega-3 fatty acids: the missing link? Archives of General Psychiatry, Vol. 56, April 1999, pp. 380-81 (letter to the editor)

FISH OIL:

TRIGLYCERIDES, HYPERTENSION, AND OBESITY

Triglycerides: A potent heart disease risk factor
MUNSTER, GERMANY. A high level of low-density lipoprotein (LDL) cholesterol combined with a low level of high-density lipoprotein (HDL) cholesterol is a potent risk factor for heart disease. There is also some evidence that high triglyceride levels are detrimental (especially in women), but just how much of a risk they pose has not been clear. Now researchers at the University of Munster report that high triglyceride levels alone or in combination with high LDL levels and low HDL levels are indeed a potent risk factor.

Their study involved 19,698 men and women, aged 16 to 65 years, who were enrolled between 1979 and 1985. After 8 years of follow-up the researchers concluded that elevated triglyceride levels are a significant and independent risk factor for a major coronary event (fatal or nonfatal heart attack or sudden cardiac death). This association held true even after adjusting for LDL and HDL cholesterol levels, age, blood pressure, smoking, angina, diabetes, and family history of heart disease. A combination of high triglyceride levels with a high LDL level and a LDL:HDL ratio greater than 5 was found to increase risk by a factor of 6. Other studies have found that a 1.0 mmol/L (88 mg/dL) increase in triglyceride levels increased the risk of cardiovascular disease in men by 30% and by 75% in women. Of particular interest is the finding that a high ratio of triglycerides to HDL cholesterol is a powerful risk factor for a major cardiac event even when LDL cholesterol levels are normal.

Editor's note: Independent research has shown that fish oil supplementation is highly effective in reducing triglyceride levels and lowering the triglyceride/HDL ratio. One study found that taking 8 fish oil capsules daily (providing 2.4 grams of eicosapentaenoic acid and 1.6 grams of docosahexaenoic acid) reduced triglyceride levels by about 26% and triglyceride/HDL ratio by 28% in women. Another study found an average reduction of 38% in triglyceride levels and an increase of HDL levels of 24% in both men and women consuming fish on a daily basis.
Cullen, Paul. Evidence that triglycerides are an independent coronary heart disease risk factor. American Journal of Cardiology, Vol. 86, November 1, 2000, pp. 943-49

Fish oils reduce cardiovascular risk factors in women
GUELPH, CANADA. Recent research has shown that a high blood level of triglycerides (triacylglycerol) is a potent risk factor for cardiovascular disease (CVD) in women. It is now also known that a high ratio of triacylglycerol to HDL cholesterol (high density lipoprotein cholesterol) is a more important risk factor for CVD in women than is a high LDL:HDL ratio. Estrogen replacement therapy (ERT) was originally believed to be protective against CVD in women, but 2 recent large studies found no such benefit. As a matter of fact, both clinical trials concluded that ERT raises triglyceride levels significantly.

Researchers at the University of Guelph have just completed a clinical trial to determine if fish oil supplementation can reduce CVD risk factors in postmenopausal women. The double-blind, randomized, placebo-controlled trial involved 35 women aged 43 to 60 years who had either experienced natural menopause (18 women) or surgical menopause (17 women). Nineteen of the women were receiving either estrogen or combined-hormone therapy and 16 were not receiving any form of HRT. The women were randomly assigned to receive either 8 capsules of fish oil concentrate (providing 2.4 grams of eicosapentaenoic acid and 1.6 grams of docosahexaenoic acid) or 8 capsules of evening primrose oil (placebo) daily. Fasting blood samples were taken and analyzed at the start of the trial and at the end of the 28-day supplementation period.

The researchers found that the women taking fish oils lowered their triacylglycerol concentrations by an average 26% (35% in women not on HRT and 19% in women on HRT). They also observed a 28% overall decrease in the important triacylglycerol:HDL ratio (39% in women not on HRT and 20% in women on HRT). The women on HRT generally had higher initial triacylglycerol concentrations and triacylglycerol:HDL ratios than the women not on HRT. The researchers conclude that postmenopausal women can reduce their risk of CVD by about 27% (whether or not they are on HRT) by supplementing with fish oils.
Stark, Ken D., et al. Effect of fish-oil concentrate on serum lipids in postmenopausal women receiving and not receiving hormone replacement therapy in a placebo-controlled, double-blind trial. American Journal of Clinical Nutrition, Vol. 72, August 2000, pp. 389-94

Fish consumption combats hypertension and obesity
PERTH, AUSTRALIA. Obesity in patients with high blood pressure is associated with high cholesterol levels, poorer glucose control, and an increased risk of atherosclerosis and heart attacks. Researchers at the University of Western Australia have just released the results of a study that clearly demonstrates that a weight-loss diet combined with daily fish consumption is highly effective in reducing blood pressure, lowering triglyceride levels while increasing "good" (HDL2) cholesterol levels and in improving glucose tolerance.

The study involved 63 men and postmenopausal women who were overweight and being treated for hypertension. The participants were randomly assigned to one of four groups. Group 1 included a daily fish meal (turbot, sardines, tuna or salmon) in their diet; group 2 consumed a calorie-restricted diet; group 3 consumed a calorie-restricted diet including a daily fish meal; and group 4 served as a control. Blood pressure, glucose tolerance, fatty acid profile, and cholesterol levels were measured at baseline and after 16 weeks on the diets.

The two calorie-restricted diets resulted in an average weight loss of 5.6 kg (12 lbs) during the first 12 weeks of the experiment. No significant weight loss was observed in the control group and the daily fish meal group. Waking blood pressures decreased by 5.5 mm Hg (systolic) and 2.2 mm Hg (diastolic) in the calorie-restricted group and by 13.0 mm Hg and 9.3 mm Hg in the group combining a daily fish meal with a calorie-restricted diet. The combination of fish consumption and weight loss improved glucose and insulin metabolism significantly and also resulted in a 38% reduction in triglyceride levels and a 24% increase in the level of "good" cholesterol (HDL2). The researchers conclude that a combination of weight loss and daily fish consumption significantly reduces the risk of cardiovascular disease among obese, hypertensive patients.
Mori, Trevor A., et al. Dietary fish as a major component of a weight-loss diet: effect on serum lipids, glucose, and insulin metabolism in overweight hypertensive subjects. American Journal of Clinical Nutrition, Vol. 70, November 1999, pp. 817-25 [57 references]

DIABETES:

Fish oil supplementation is safe for diabetics
PARIS, FRANCE. People suffering from type II diabetes often have high blood levels of triglycerides and are therefore prone to coronary heart disease. Fish oils are known to be effective in lowering triglyceride levels, but concern has been expressed that they may also increase low-density lipoprotein (LDL) levels and be deleterious to glucose control.

Medical researchers at the Hotel-Dieu hospital now report the results of a study designed to investigate these concerns. The study involved 10 men with type II diabetes (average age of 54 years). The men were randomized into two groups in the double-blind crossover study. Group 1 supplemented with 6 grams/day of fish oils (containing 320 mg of eicosapentaenoic acid [EPA] and 215 mg of docosahexaenoic acid [DHA]) for two months while group 2 supplemented with 6 grams/day of sunflower oil (containing 65% linoleic acid). At the end of the two months all participants went through a 2-month wash-out period and group 1 was then assigned to supplement with sunflower oil while group 2 was given fish oil supplements. All participants maintained their regular diet (55% carbohydrates, 15% protein, and 30% fat) and continued with their medications throughout the study except for cholesterol-lowering drugs which were discontinued 2 months before the start of the trial.

The researchers noted a considerable increase in both EPA and DHA content in blood plasma phospholipids and in red blood cell membranes after two months on the fish oil supplements. Triglyceride levels and the level of plasma lipoprotein(a) were both significantly lowered following fish oil supplementation. No adverse effects on glucose control were observed; there was a small increase in the LDL level, but this was compensated for by a similar increase in the HDL (high-density lipoprotein) level so that the important LDL/HDL ratio remained unchanged. The researchers conclude that fish oil supplementation is effective in lowering triglyceride levels in type II diabetics and has not adverse effects on glycemic control or overall cholesterol levels.
Luo, Jing, et al. Moderate intake of n-3 fatty acids for 2 months has no detrimental effect on glucose metabolism and could ameliorate the lipid profile in type 2 diabetic men. Diabetes Care, Vol. 21, May 1998, pp. 717-24

Fish oils and fiber benefit diabetics
CLEVELAND, OHIO. Patients with non-insulin-dependent diabetes mellitus (NIDDM) often suffer from abnormal lipid (fat) and lipoprotein metabolism resulting in unfavourable cholesterol levels and an accompanying increase in the risk of heart disease. Numerous studies have shown that fish oil supplementation lowers the levels of very-low-density-lipoprotein (VLDL) and triglycerides (triacylglycerol), but has little effect on the levels of low-density-lipoprotein (LDL) and total cholesterol. There has also been some reports that fish oil supplementation may worsen glycemic (glucose) control. Now medical researchers at the Case Western Reserve University report that adding soluble fiber to the fish oil supplementation regimen is highly beneficial. Their experiment involved 15 non-obese NIDDM patients (12 men and 3 women) aged 32 to 74 years. For the first four weeks the patients received 20 grams of fish oil per day (equivalent to six grams of n-3 fatty acids). During the next four weeks all patients received the fish oil plus 15 grams/day of soluble apple pectin. During the final four weeks both supplements were withdrawn. The patients continued their usual diabetic diet and medication during the entire study period. Analysis of blood samples showed that fish oil supplementation alone lowered the levels of triacylglycerol and VLDL cholesterol by 41 per cent and 36 per cent respectively. No changes were observed in total cholesterol, LDL cholesterol or HDL cholesterol. When apple pectin was added to the treatment triacylglycerol and VLDL cholesterol levels were both lowered by 38 per cent, but in addition total cholesterol levels decreased by 13 per cent and LDL cholesterol by 7 per cent. There was no significant change in HDL cholesterol level. Fasting and two-hour postprandial plasma glucose concentrations were not affected by the fish oil or fish oil/pectin supplementation and no changes in serum levels of zinc, magnesium, and copper were observed. Plasma levels of triglycerides and cholesterols returned to pre-treatment levels four weeks after discontinuation of supplementation. The researchers conclude that a combination of fish oil supplementation and increased fiber intake (up to 40 grams/day total) may be a beneficial addition to the conventional treatment of high cholesterol levels in NIDDM patients.
Sheehan, John P., et al. Effect of high fiber intake in fish oil-treated patients with non-insulin-dependent diabetes mellitus. American Journal of Clinical Nutrition, Vol. 66, November 1997, pp. 1183- 87

Diabetics may benefit from fish oil supplementation
NAPLES, ITALY. Animal studies have shown that fish oil supplementation has a beneficial effect on insulin resistance and can prevent its development in animals fed a high-fat diet. It is also known that a high fish intake can delay the development of diabetes in glucose-intolerant individuals. Researchers at the Federico II University recently set out to investigate if long-term supplementation with fish oils would improve insulin sensitivity in patients with non-insulin-dependent diabetes (NIDDM). The clinical trial involved 16 NIDDM patients (average age of 56 years) who, after a 3 week run-in period during which they received 3 olive oil capsules per day, were assigned to receive either fish oil capsules or olive oil capsules for a further 6-month period. For the first two months the participants received either 3 fish oil capsules daily (320 mg eicosapentaenoic acid [EPA] and 530 mg docosahexaenoic acid [DHA] per capsule) or 3 placebo capsules (each containing 1 gram of olive oil). During the last four months these dosages were reduced to 2 fish oil or 2 placebo capsules daily. The patients were evaluated at the beginning and end of the trial and maintained their usual diet and medications (except for cholesterol- lowering drugs) during the entire trial period.

The researchers concluded that fish oil supplementation induced a significant decrease in triglyceride concentrations particularly in the level of very-low-density lipoprotein (VLDL) triglycerides (a reduction of 45%). There was also a significant decrease in VLDL cholesterol levels (47% drop) and a 14% increase in LDL cholesterol. There was no significant change in blood glucose control and, contrary to expectations, no significant improvement in insulin resistance despite the fact that red blood cell levels of EPA and DHA increased significantly. The researchers conclude that long-term fish oil supplementation lowers triglyceride levels in NIDDM patients without adversely affecting blood glucose control. NOTE: This study was partially funded by Pharmacia, Farmitalia Carlo Erba, Milan, Italy.
Rivellese, Angela A., et al. Long-term effects of fish oil on insulin resistance and plasma lipoproteins in NIDDM patients with hypertriglyceridemia. Diabetes Care, Vol. 19, November 1996, pp. 1207-13

Diabetes and fish oil supplementation
EDMONTON, CANADA. Diabetics are at significantly increased risk for cardiovascular disease and any dietary intervention that could decrease this risk would be of great importance. Studies have shown that fish oil supplementation lowers triglycerides, very low density lipoprotein (VLDL) levels, and blood pressure in non-diabetic individuals and thereby diminishes their risk of heart disease. Unfortunately, some early experiments with fish oil supplementation in type II diabetics reported adverse effects on glycemic control and cholesterol levels.

Researchers at the University of Alberta have just released the results of a new study aimed at evaluating the overall effects of fish oil supplementation in type II diabetics. Eleven subjects with non-insulin- requiring type II diabetes took part in the randomized, double-blind, crossover study. All participants underwent a 3-month run-in period during which they supplemented with olive oil capsules (placebo). They were then randomized into two groups with one group supplementing with fish oil capsules (about 2.0 grams/day) and the other group supplementing with flax seed oil capsules. After 3 months the participants underwent a crossover to the alternative oil for a final 3 months of supplementation.

All study participants had acceptable blood levels of total cholesterol, triglycerides, high density lipoproteins, low density lipoproteins, and low density triglycerides prior to initiating supplementation with fish oil or flax seed oil. Supplementation did not change these levels except in the case of triglycerides which were markedly reduced after fish oil supplementation. Glycemic control was not adversely affected by supplementation with either oil and there was a trend towards decreased insulin sensitivity in the group taking fish oils. The researchers conclude that fish oil supplementation is safe in type II diabetes and can help ameliorate cardiovascular disease risk factors such as high triglyceride levels. They also conclude that flax seed oil supplementation, while having no adverse effects, is not of significant benefit in type II diabetes. NOTE: This study was partially funded by the Canadian Dairy Bureau.
McManus, Ruth M., et al. A comparison of the effects of n-3 fatty acids from linseed oil and fish oil in well-controlled type II diabetes. Diabetes Care, Vol. 19, May 1996, pp. 463-67

Fish oils recommended for diabetes and hypertension
TROMSO, NORWAY. Fish and fish oils help protect against the development of atherosclerosis and heart disease. It is believed that fish oils exert their protective effect by lowering blood pressure and the levels of triglycerides and very-low-density lipoprotein (VLDL). Fish oils are also believed to reduce platelet aggregation and to suppress the growth of smooth-muscle cells in the arterial walls. Many people with hypertension also suffer from diabetes and there has been concern that fish oil supplementation may aggravate problems with glucose intolerance. Researchers at the University of Tromso now report that fish oil supplementation lowers blood pressure significantly in people with hypertension and has no effect on glucose control even in people with mild diabetes. The study involved 78 obese volunteers with essential hypertension. The participants were randomly assigned to one of two equal-sized groups. The fish oil group received four fish oil capsules a day (containing a total of 3.4 grams of a mixture of eicosapentaenoic acid and docosahexaenoic acid) for a period of 16 weeks. The control group received four corn oil capsules a day.

At the end of the test period the average (mean) systolic blood pressure had dropped by 4.4 mm Hg and the diastolic pressure by 3.2 mm Hg in the fish oil group. The average blood pressure in the control group did not change. The researchers also found that plasma triglyceride and VLDL levels in the fish oil group decreased significantly (by about 9 per cent) while they increased significantly (by about 12 per cent) in the control group. There were no changes in total or low-density-lipoprotein levels in either group. Extensive tests (oral glucose tolerance, hyperglycemic and hyperinsulemic clamps) were done to evaluate the effect of fish oil supplementation on glucose control. No adverse effects were found. An editorial accompanying the research report concludes that fish or fish oil is useful in the prevention of vascular disease in diabetics. Patients with diabetes should eat fish two to three times a week or, as an alternative, supplement with two to three one gram capsules of fish oil per day.
Toft, Ingrid, et al. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. Annals of Internal Medicine, Vol. 123, No. 12, December 15, 1995, pp. 911- 18
Connor, William E. Diabetes, fish oil, and vascular disease. Annals of Internal Medicine, Vol. 123, No. 12, December 15, 1995, pp. 950-52

Fish oil supplementation recommended for type II diabetics
DALLAS, TEXAS. High cholesterol and triglyceride levels are common among diabetics and are major contributors to their increased risk of cardiovascular disease. Researchers at the Texas Woman's University and the University of Texas Medical Center now report that fish oil supplementation can markedly decrease cholesterol and triglyceride levels without adversely affecting glycemic control.

Their study involved 40 patients with non-insulin-dependent diabetes mellitus (NIDDM) who had abnormally high blood plasma levels of one or more of the following lipids: total cholesterol (greater than 5.17 mmol/L), LDL cholesterol (greater than 3.36 mmol/L), or triglycerides (greater than 6.47 mmol/L). After a four-week baseline phase during which cholesterol levels, weight, blood pressure, and diabetes control were assessed every two weeks the participants were randomly assigned to one of four groups - daily dose of 9 grams of corn oil (57% linoleic acid), 18 grams of corn oil, 9 grams of fish oil (29% EPA and 27% DHA), and 18 grams of fish oil. All participants were assessed every two weeks during the 12- week supplementation period.

A significant reduction in the levels of very-low-density lipoproteins, triglycerides and very-low-density triglycerides was observed among the participants supplementing with fish oils at both the 6-week and 12-week mark. There were no significant differences in the effect of 9 grams/day versus 18 grams/day supplementation. The level of LDL cholesterol increased temporarily at the 6-week mark, but this effect was no longer present at the 12-week examination. Neither fish oil nor corn oil supplementation produced any significant changes (over baseline values) in total cholesterol levels, HDL cholesterol levels, fasting plasma glucose, weight or blood pressure. A small increase in VLDL cholesterol was noted in the corn oil group at the end of the experiment.

The researchers conclude that fish oil supplementation is useful in lowering triglycerides in diabetics with excessive levels and has no deleterious effect on glycemic control.
Morgan, Wanda A., et al. A comparison of fish oil or corn oil supplements in hyperlipidemic subjects with NIDDM. Diabetes Care, Vol. 18, January 1995, pp. 83-86

GARLIC

Fish oils and cholesterol
KANSAS CITY, MISSOURI. Dr. William S. Harris of the Mid America Heart Institute has released a comprehensive study of the results of 68 major clinical trials aimed at determining the effects of fish oil supplementation on cholesterol and triglyceride levels. The studies included over 2800 participants, lasted from 2 to 52 weeks, and involved supplementation with around 10 grams/day of fish oils. The participants received either fish oil or placebo (mostly olive oil) and included people with normal as well as people with elevated cholesterol and triglyceride levels. Based on the results of the studies Dr. Harris concludes that fish oil supplementation lowers blood levels of triglycerides by about 25-30%; he points out that this is equivalent to the effect obtained by taking the drug gemfibrozil. Fish oils tend to increase the levels of low-density cholesterol (LDL) by about 5-10%, but has little effect on high-density cholesterol (HDL) levels. Overall cholesterol levels are not affected by fish oil supplementation. Dr. Harris emphasizes that the triglyceride-reducing effect is unique to long-chain omega-3 acids found in fish oils. The shorter chain omega-3 oil, alpha-linolenic acid (found in flax seed oil) has no effect on triglyceride or cholesterol levels.
Harris, William S. n-3 fatty acids and serum lipoproteins: human studies. American Journal of Clinical Nutrition, Vol. 65 (suppl), 1997, pp. 1645S-54S [83 references]

Fish oils reduce cardiovascular risk factors
OSLO, NORWAY. High blood levels of triglycerides and fibrinogen are known risk factors for cardiovascular disease. Fibrinogen is a large protein molecule which is a key factor in blood coagulation. High levels of fibrinogen aggravate the symptoms of intermittent claudication and speeds up the progression of atherosclerosis. Recent research has shown that fibrinogen level is a more reliable indicator of heart disease risk than is total cholesterol level.

Researchers at the University of Oslo now report that fish oil supplementation is effective in lowering both triglyceride and fibrinogen levels. Their study involved 64 healthy men between the ages of 35 and 45 years. The participants were randomly assigned to receive either 14 1-gram capsules of fish oils or 14 1- gram capsules of olive oil every day for six weeks. The fish oil capsules contained 25.7% eicosapentaenoic acid (EPA) and 20.5% docosahexaenoic acid (DHA) and the olive oil capsules contained about 80% oleic acid. Blood samples were taken and analyzed at the start of the study, 3 and 6 weeks into the study, and 3 weeks after stopping supplementation. The red blood cell (phospholipid phase) content of EPA increased markedly after supplementation; DHA level increased slightly and the level of both linoleic acid and arachidonic acid decreased significantly. Blood level of fibrinogen dropped an average of 13% (from 2.73g/L to 2.37 g/L) after 3 weeks, but returned to baseline 3 weeks after stopping fish oil supplementation. There were no changes in fibrinogen levels in the olive oil group. Triglyceride levels decreased by an average of 22% (from 1.58 mmol/L to 1.23 mmol/L) after 6 weeks in the fish oil group, but increased by about 19% in the olive oil group. Values in both groups reverted to baseline 3 weeks after ceasing supplementation. Total cholesterol level and the level of LDL cholesterol (low-density lipoprotein) did not change with supplementation in either group, but a small transient decrease in the level of HDL (high-density lipoprotein) cholesterol was noted in the fish oil group. Blood pressure fell slightly in both groups after 3 and 6 weeks of supplementation, but reverted to baseline once supplementation was discontinued.

The researchers conclude that the antithrombotic (blood clot preventing) effect of fish oils may be due to their ability to lower fibrinogen levels.
Flaten, Hugo, et al. Fish-oil concentrate: effects of variables related to cardiovascular disease. American Journal of Clinical Nutrition, Vol. 52, 1990, pp. 300-06

A regular diet containing fish oils improves fat tolerance
PORTLAND, OREGON. An experiment involving seven healthy human subjects was carried out to determine if the composition of a background diet fed for four weeks would influence the rise in triglyceride level experienced after consuming a fatty test meal. The three background diets contained 30-40% of calories as saturated fats, polyunsaturated vegetable oils, and salmon oils respectively. Fasting triglyceride levels in the three regimes were 72+-19, 76+-37, and 46+-11 mg/dl respectively. It was found that the rise in plasma triglyceride level after a test meal containing 50 grams of fat was significantly lower for subjects who had been on the fish oil background diet. This relationship held true independent of the type of fat in the test meal (saturated, vegetable oil, or fish oil). The results suggest that long term (but not acute) fish oil consumption may improve fat tolerance.
Harris, William S., et al. Reduction of postprandial triglyceridemia in humans by dietary n-3 fatty acids. Journal of Lipid Research, Volume 29, No. 11, November 1988, pp. 1451-1460

Fish consumption combats hypertension and obesity

PERTH, AUSTRALIA. Obesity in patients with high blood pressure is associated with high cholesterol levels, poorer glucose control, and an increased risk of atherosclerosis and heart attacks. Researchers at the University of Western Australia have just released the results of a study that clearly demonstrates that a weight-loss diet combined with daily fish consumption is highly effective in reducing blood pressure, lowering triglyceride levels while increasing "good" (HDL2) cholesterol levels and in improving glucose tolerance.

Fish oils benefit heart transplant patients
OSLO, NORWAY. Most heart transplant patients (60-100%) develop hypertension within six months following their surgery. It is believed that the increase in blood pressure is caused by the anti-rejection drug cyclosporine. Medical doctors at the University of Oslo now report that supplementation with fish oils will prevent the development of hypertension. Their clinical trial involved 28 heart transplant patients who, 4 days after surgery, were randomized to receive either 4 grams of fish oil (providing 1.9 g of eicosapentaenoic acid [EPA] and 1.5 g of docosahexaenoic acid [DHA] as well as 14.8 mg of vitamin E) or 4 grams of corn oil with vitamin E once a day for 6 months. The patients' blood pressure (24-hour readings) were measured 12 days, 1 month, 2 months, 3 months, and 6 months after surgery. Blood samples were also taken for analysis of EPA and DHA content.

The researchers found that the average (mean) systolic blood pressure in the placebo group had increased by 17 mm Hg at the end of the 6-month supplementation period. In contrast, the average systolic blood pressure in the fish oil group had decreased by 2 mm Hg. The average diastolic pressure in the placebo group increased by 21 mm Hg as compared to an increase of only 10 mm Hg in the fish oil group. The researchers also observed a clear inverse correlation between the blood serum levels of EPA + DHA and systolic blood pressure. They conclude that daily supplementation with 4 grams of fish oil can markedly reduce the tendency to develop hypertension among cyclosporine-treated heart transplant patients.
Andreassen, Arne K., et al. Hypertension prophylaxis with omega-3 fatty acids in heart transplant recipients. Journal of the American College of Cardiology, Vol. 29, May 1997, pp. 1324-31

Controlled trials confirm blood pressure reduction with fish oils
BOSTON, MASSACHUSETTS. Numerous studies have concluded that fish oil consumption lowers blood pressure, but a few have found no effect and others have been inconclusive. Researchers at the Harvard Medical School have just completed a major evaluation of the results of 31 placebo-controlled trials involving 1356 subjects. They found that fish oil supplementation (mean dose of 5.6 grams/day) lowers systolic blood pressure (first [highest] reading of blood pressure measurement) by an average of 3.4 mm Hg and diastolic pressure (second [lowest] reading) by an average of 2.0 mm Hg. The effect is highly dose-dependent with 1 gram/day of fish oil lowering systolic pressure by an average of 0.66 mm Hg and diastolic pressure by an average of 0.35 mm Hg. Fish oil supplementation does not affect blood pressure in people with normal blood pressure, but relatively dramatic effects are seen in patients with high cholesterol levels and in patients with atherosclerosis. Both eicosapentaenoic and docosahexaenoic acids (the main components of fish oils) are effective in blood pressure reduction with docosahexaenoic acid being slightly superior. The Harvard researchers conclude that supplementation with 7.7 to 9 grams/day of fish oils will reduce systolic blood pressure by 4 mm Hg and diastolic pressure by 3 mm Hg in hypertensive individuals. Blood pressure reductions may be substantially larger among patients with atherosclerosis or high cholesterol levels.
Morris, Martha Clare, et al. Does fish oil lower blood pressure? A meta-analysis of controlled trials. Circulation, Vol. 88, No. 2, August 1993, pp. 523-33

Fish oils reduce blood pressure
BALTIMORE, MARYLAND. The daily consumption of fish oils (omega-3 polyunsaturated fatty acids) can significantly lower blood pressure in people suffering from hypertension. The benefit of the fish oils is comparable to that obtainable by sodium reduction and weight loss. A group of medical researchers at the Johns Hopkins Medical School evaluated the results of 17 clinical trials involving supplementation with fish oils for periods of three months or less. They found that the consumption of 3 grams per day of fish oil (6-10 capsules) or more led to impressive reductions in the blood pressure of hypertensive individuals. Systolic pressure was lowered by an average of 5.5 mm Hg and diastolic pressure was lowered by 3.5 mm Hg. The effect was found to be more pronounced at higher blood pressures and no significant effects were noted in people with normal blood pressure. Twenty-eight percent of the participants in the trials reported side effects such as a fishy taste or belching. The doctors suggest that fish oil supplementation may be a valuable therapy in patients with borderline hypertension who would otherwise be candidates for conventional drug therapy. They point out that the effects of long term (> 3 months) supplementation are unknown and that lower dosages than 3 g/day may be desirable and perhaps as effective. NOTE: Systolic pressure is the first (highest) reading given for a blood pressure measurement, diastolic is the second (lowest) reading, i.e. 120/80.
Appel, Lawrence J., et al. Does supplementation of diet with "fish oil" reduce blood pressure? Archives of Internal Medicine, Vol. 153, June 28, 1993, pp. 1429-38

Fish oil supplementation reduces blood pressure
CINCINNATI, OHIO. Conventional blood pressure lowering medications often have detrimental effects on quality of life and may lead to unfavourable changes in cholesterol levels. Several studies have found that supplementation with large amounts of fish oil (5-15 grams/day) lowers blood pressure significantly in hypertensive individuals. Whether smaller amounts are equally effective has been open to question.

Researchers at the University of Cincinnati (Ohio) College of Medicine now report that daily supplementation with low doses of fish oil is indeed effective in lowering blood pressure in mildly hypertensive patients. Their study involved 33 patients (men and women) with a diastolic pressure between 90 and 104 mm Hg. After a four-week wash-out period during which the participants discontinued all medications the patients were randomly allocated to one of two groups. Group 1 supplemented with 2.04 grams/day of fish oil containing 410 mg of eicosapentaenoic acid and 285 mg of docosahexaenoic acid. Group 2 was given a placebo capsule daily containing safflower oil (80% linoleic acid). After 12 weeks and a four-week wash-out period the groups switched supplementation so that group 1 now received the placebo. Blood pressure, heart rate, and body weight were recorded at two- week intervals during the study and blood samples were collected and analyzed at the beginning and end of each treatment period.

The researchers found that fish oil supplementation reduced diastolic pressure (sitting) by an average of approximately 4.4 mm Hg and systolic pressure by an average of 6.5 mm Hg when compared to values obtained prior to the start of treatment. There were no adverse effects on cholesterol levels. They conclude that fish oil supplementation is a safe and effective way of lowering blood pressure in mildly hypertensive subjects, but noted that the beneficial effects wear off relatively quickly once supplementation is discontinued. NOTE: This study was funded by a grant from RP Scherer Ltd. a manufacturer of fish oil products.
Radack, Kenneth, et al. The effects of low doses of n-3 fatty acid supplementation on blood pressure in hypertensive subjects. Archives of Internal Medicine, Vol. 151, June 1991, pp. 1173-80

Salt restriction and fish oil supplementation lower blood pressure
ADELAIDE, AUSTRALIA. Salt (sodium) restriction can help lower blood pressure in people with hypertension, but is less effective in people with normal pressure. Blood pressure tends to rise with age and there is some evidence that sodium restriction may help reduce this age-related increase. Fish oil supplementation is also effective in lowering blood pressure in hypertensive individuals, but its effect on people with normal pressure is unclear.

Australian researchers report that a combination of fish oil supplementation and salt restriction is highly effective in lowering both systolic and diastolic blood pressure in elderly people with normal pressures. Their study involved 50 healthy volunteers aged 60 to 80 years whose mean initial systolic and diastolic blood pressures were 133 and 77 mm Hg respectively. The participants were randomly assigned to one of four groups. Group 1 supplemented with 8 fish oil capsules per day (providing 4.2 g of omega-3 fatty acids) while maintaining a normal sodium intake. Group 2 supplemented with fish oil while consuming a low-sodium diet. Group 3 supplemented with sunflower oil combined with normal sodium intake while group 4 took sunflower oil while consuming a low-sodium diet. After 4 weeks the mean systolic blood pressure in group 1 had decreased by 8.9 mm Hg and the diastolic pressure by 6.0 mm Hg. There were no significant changes in blood pressure in the group supplementing with fish oil while maintaining a normal sodium intake. The researchers conclude that sodium restriction combined with fish oil supplementation effectively lowers blood pressure. They suggest that this finding may be of particular relevance in the treatment of hypertension in the elderly.
Cobiac, Lynne, et al. Effects of dietary sodium restriction and fish oil supplements on blood pressure in the elderly. Clinical and Experimental Pharmacology and Physiology, Vol. 18, 1991, pp. 265-68

Fish consumption reduces lung cancer risk

NAGOYA, JAPAN. Lung cancer is the leading cause of cancer deaths in Japan even though the incidence and mortality is still less than two-thirds of that found in the USA and the UK. Japanese researchers have just completed a study aimed at determining the association between lung cancer and diet. Their study involved 748 men and 297 women aged 40 to 79 years who had been diagnosed with lung cancer and 2964 male and 1189 female cancer-free controls.
The researchers found that both men and women who ate cooked or raw fish five times a week or more had half the incidence of lung adenocarcinoma when compared to participants who ate cooked or raw fish less than once a week. Women who consumed tofu (soybean curds) five times a week or more were found to have half the risk of adenocarcinomas, as compared to women who consumed tofu less than once a week. Frequent consumption of carrots was found to be beneficial for women, but detrimental for men especially smokers. Green vegetables were found to be highly beneficial for men, but not statistically so for women. There was also some evidence that increased coffee consumption is associated with an increased risk of squamous cell and small cell lung carcinomas in men. Increased consumption of dried or salted fish was not beneficial for men or women. The researchers speculate that this is because the processing destroys the healthy omega-3 oils (eicosapentaenoic acid and docosahexaenoic acid) present in raw and cooked fish.
Takezaki, T., et al. Dietary factors and lung cancer risk in Japanese with special reference to fish consumption and adenocarcinomas. British Journal of Cancer, Vol. 84, No. 9, May 4, 2001, pp. 1199- 1206

Docosahexaenoic acid halts melanoma:

We do not usually report on animal or test tube experiments, but found the results of this study so intriguing that we decided to make an exception.

VALHALLA, NEW YORK. The incidence of cutaneous malignant melanoma is growing rapidly among persons with fair skin. It is estimated that one in 75 Americans will develop melanoma within their lifetime. Melanoma has a pronounced tendency to spread to other organs (metastasis) and the 5-year survival rate for metastatic melanoma is less than 10%. There is growing evidence that diet can influence the risk of developing melanoma. It is now believed that a high intake of omega-6 fatty acids stimulates the growth of melanoma and other cancers whereas omega-3 fatty acids suppress the growth of cancer cells.

Researchers at the New York Medical College and the American Health Foundation have just released the results of a laboratory experiment which clearly shows that docosahexaenoic acid (DHA), a main component of fish oil, is highly effective in inhibiting the growth of human melanoma cells. The researchers treated 12 different human metastatic melanoma cell cultures (in vitro) with DHA and found that more than 50% of them stopped growing. They urge further testing of their findings in full-scale clinical trials involving patients with melanoma. They conclude that "if DHA is capable of suppressing cell and tumor growth and metastatic potential in in vivo models of melanoma, a clinical trial of DHA would be warranted as an adjuvant to current surgical and chemotherapeutic interventions".
Albino, Anthony P., et al. Cell cycle arrest and apoptosis of melanoma cells by docosahexaenoic acid: association with decreased pRb phosphorylation. Cancer Research, Vol. 60, August 1, 2000, pp. 4139- 45

Fish oils combat weight loss in cancer patients
EDINBURGH, UNITED KINGDOM. Cachexia (abnormal weight loss) is a major problem in many types of cancer especially cancer of the pancreas. Preliminary research has shown that supplementing the diet with fish oils, about 2.2 grams of EPA (eicosapentaenoic acid) and 1.4 grams of DHA (docosahexaenoic acid) daily, will stabilize weight in patients with inoperable pancreatic cancer. Now researchers at the Royal Infirmary of Edinburgh report that patients with pancreatic cancer can actually gain weight by consuming a nutritional supplement fortified with fish oils. The experiment involved 20 patients with inoperable pancreatic cancer (aged 18 to 80 years). The participants were asked to ingest two cans of fish oil-enriched nutritional supplement per day in addition to their normal food intake. The nutritional supplement provided 310 kcal per can and contained 16.1 g protein, 49.7 g carbohydrate, 6.5 g fat, 1.09 g EPA, 0.46 g DHA, and 28 essential vitamins and minerals.

After three weeks the patients had gained an average (median) of 1 kg in weight and at seven weeks an average of 2 kg. A significant improvement in performance status and appetite was also noted after three weeks on the supplement. Other research has shown that EPA inhibits the growth of pancreatic cancer cells in vitro. It is therefore of interest to note that the average survival time among the patients was over eight months. This compares very favourably with the normal survival time of 4.1 months and is at least as good as the survival time that can be obtained with aggressive chemotherapy.

The researchers conclude that a fish oil-enriched nutritional supplement has the potential to be a safe and effective means of preventing weight loss in cancer patients and may even increase survival time in patients with cancer of the pancreas. NOTE: This study was partially funded by Abbott Laboratories, the maker of the nutritional supplement.
Barber, M.D., et al. The effect of an oral nutritional supplement enriched with fish oil on weight-loss in patients with pancreatic cancer. British Journal of Cancer, Vol. 81, No. 1, September 1999, pp. 80-86

Fish oils improve survival of cancer patients
PATRAS, GREECE. Chemotherapy and other conventional medical treatments have proven ineffective in improving quality of life and survival of patients with end stage cancer. Now Greek medical researchers report that fish oil supplementation markedly increases the survival time for cancer patients with generalized malignancy. Their study involved 60 patients with generalized solid tumors. The patients were divided into two groups with one group receiving 18 grams/day of fish oil (six capsules of MAXEPA three times daily containing 170 mg eicosapentaenoic acid [EPA] and 115 mg docosahexaenoic acid [DHA] per capsule) and the other group receiving a placebo. The fish oil group also received 200 mg of vitamin E daily to compensate for the oxidative effect of the fish oil. Each group included 15 well-nourished and 15 malnourished patients. None of the well-nourished patients suffered from cancer cachexia (abnormally low weight and general weakness). The researchers measured the level of T cells, natural killer cells, and the synthesis of interleukin and tumor necrosis factor before the start of the supplementation and on day 40 of the trial. The study followed all patients until they died. Malnourished patients were found to have a considerably impaired immune function and a decreased production of tumor necrosis factor; both parameters were restored through fish oil supplementation. Malnourished patients overall had a much shorter survival time than well-nourished ones (mean of 213 days versus 481 days). Both malnourished and well-nourished patients who received fish oil and vitamin E survived significantly longer than did patients on placebo. The researchers speculate that fish oils exert their beneficial effect by decreasing the body's production of prostaglandin E2 which is believed to play an important role in the initiation and progression of cancer. They conclude that supplementation with dietary omega-3 polyunsaturated fatty acids, specifically fish oils with an antioxidant such as vitamin E may offer significant palliative support to cancer patients with end stage metastatic disease.
Gogos, Charalambos A., et al. Dietary omega-3 polyunsaturated fatty acids plus vitamin E restore immunodeficiency and prolong survival for severely ill patients with generalized malignancy. Cancer, Vol. 82, January 15, 1998, pp. 395-402

Fat consumption and cancer
LONDON, UNITED KINGDOM. Several major epidemiologic studies have found a clear association between a high dietary fat intake and the risk of developing breast and colon cancer. The correlation is particularly strong in the case of animal fats. One study found that a high fish or fish oil consumption is protective against later stage colon cancer in men, but has no effect on mortality from breast cancer. British medical researchers now report that fish and fish oils not only protect against colon cancer in men, but also against colon and breast cancer in women. This protective effect, however, is only apparent in countries where the intake of animal fats is high. In other words, a high intake of fish or fish oils counteracts the detrimental effects of a high animal fat consumption.

The study compared cancer mortality rates in 24 European countries, Canada and the USA with fish consumption and the intake of animal fats. In countries where the animal fat intake was high the researchers found a clear inverse correlation between the ratio of fish fat to animal fat and the risk of developing breast cancer in women and colon cancer in both men and women. A similar correlation was found between cancer risk and the ratio of fish fat to total fat intake.

The researchers conclude that a 15% decrease in animal fat intake combined with a 3-fold increase in fish oil intake could possibly reduce male colon cancer risk by as much as 30% in countries with a high animal fat intake. A 3-fold increase in fish oil intake could be achieved by eating fish three times a week or by taking two standard fish oil capsules daily.
Caygill, C.P.J., et al. Fat, fish, fish oil and cancer. British Journal of Cancer, Vol. 74, No. 1, July 1996, pp. 159-64

Colon cancer progression associated with fatty acid

BADALONA, SPAIN. Several epidemiological studies have shown that high fat diets are associated with an increased risk of colon cancer. Other studies have shown that diets rich in fish and fish oils are protective against colon cancer. Spanish medical researchers have just released the results of a major study aimed at determining if and how polyunsaturated fatty acids play a role in the progression of adenomas (benign polyps) to full-blown colon cancer. The study involved 27 patients with sporadic benign polyps of the rectum or colon, 22 patients with cancer of the colon or rectum, and 12 subjects with a normal colon. The researchers measured the fatty acid profile of blood plasma and biopsy samples of the lining of the colon from both diseased and normal areas. They found no differences between polyp patients and patients with a normal colon as far as plasma profile and normal colon lining profile was concerned. However, there was a significant difference between the fatty acid profile of normal colon tissue and diseased colon tissue in adenoma patients. Diseased lining tissue was found to have higher levels of linoleic acid, dihomogammalinolenic acid, and eicosapentaenoic acid (EPA) and lower levels of alpha-linolenic and arachidonic acids. There was also a very significant stepwise reduction in EPA content of diseased colon lining from the benign polyp stage to the most severe colon cancer stage.

The researchers conclude that there are significant changes in the levels of n-3 and n-6 fatty acids early on in the sequence leading from benign polyps to colon cancer and speculate that these changes might participate in the progression to colon cancer. They recommend further work to investigate the benefits of long-term dietary manipulation in view of the finding that low-dose fish oil supplementation normalizes the cell proliferation pattern in patients with sporadic polyps.
Fernandez-Banares, F., et al. Changes of the mucosal n3 and n6 fatty acid status occur early in the colorectal adenoma-carcinoma sequence. Gut, Vol. 38, 1996, pp. 254-59

Fish oils help patients with pancreatic cancer
EDINBURGH, UNITED KINGDOM. Cachexia (abnormally low weight, weakness, and general bodily decline) is common in patients suffering from pancreatic cancer. Cachexia makes patients more prone to infections, can shorten their survival, and reduce their mobility.

Researchers at the Royal Infirmary of Edinburgh have released the results of a study which clearly shows that fish oil supplementation can halt and even reverse cachexia in patients with pancreatic cancer. The study involved 18 patients with inoperable pancreatic cancer (9 had stage IV tumors). The patients were started out on 2 grams/day of fish oils (containing 360 mg of eicosapentaenoic acid and 240 mg of docosahexaenoic acid). The dose was subsequently increased by 2 grams/day every week until the patients' body tolerance was reached. The average final intake was 12 grams/day. Prior to entering the trial the average (mean) weight loss among the patients was 2.9 kg (6.3 lbs) per month. After 3 months of fish oil supplementation an average weight gain of 0.3 kg/month was observed among the patients. Overall, 11 patients (61%) gained weight, 3 became weight-stable, and 4 continued to lose weight, but at a significantly reduced rate. The concentration of eicosapentaenoic acid in plasma phospholipids increased from 0 to 5.3% of total fatty acids after 1 month of supplementation while the concentration of docosahexaenoic acid increased to 6.6% from a base level of 3.5%. The researchers conclude that fish oil supplementation arrests weight loss in cancer patients with cachexia.
Wigmore, Stephen J., et al. The effect of polyunsaturated fatty acids on the progress of cachexia in patients with pancreatic cancer. Nutrition (suppl), Vol. 12, No. 1, 1996, pp. S27-S30

Fish consumption and colon cancer
LONDON, UNITED KINGDOM. British researchers have published a major epidemiologic study dealing with the association between fish consumption and the incidence of breast and colon cancer, The researchers gathered data concerning the consumption of fish in 25 European countries for the periods 1961-63, 1974-76 and 1984-86. They also determined the standardized mortality rates for breast and colon cancer for the period 1983-87 for the same 25 countries. A statistical evaluation of the data showed a strong inverse correlation between recent fish consumption and colon cancer in men. The correlation was somewhat weaker for fish consumption 10 years earlier and non-existent for consumption 23 years earlier. A similar pattern was found for women, but the correlations were not statistically significant. The researchers found no correlation between breast cancer mortality and fish consumption at any time. They conclude that the consumption of fish and fish oils helps protect against colon cancer in its later stages, but does not affect the initiation stage. They believe fish oils exert their protective effect by inhibiting the formation of prostaglandin PGE2 which has been associated with the development and progression of colon cancer.
Caygill, C.P.J. and Hill, M.J. Fish, n-3 fatty acids and human colorectal and breast cancer mortality. European Journal of Cancer Prevention, Vol. 4, 1995, pp. 329-32

Fish oil supplementation helps prevent colon cancer
ROME, ITALY. The presence of benign polyps (adenomas) is a significant risk factor for full-blown colon or rectal cancer. Animal studies have shown that the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibit the development of colon cancer and epidemiological studies have shown that fish consumption is inversely proportional with the incidence of colon cancer. Encouraged by these findings, researchers at the Catholic University of Rome set out to determine if fish oil supplementation would inhibit the development of benign polyps, the precursors of colon cancer.

Their study involved 34 men and 26 women who had just undergone surgery to remove benign polyps from their colon. The patients were divided into 4 groups. Group 1 was supplemented with 1.4 grams of EPA and 1.1 grams of DHA per day, group 2 with 2.7 grams of EPA and 2.4 grams of DHA, group 3 with 4.1 grams of EPA and 3.6 grams of DHA while group 4 received placebo capsules containing mainly olive oil. Biopsy samples from the lower part of the colon lining and blood samples were taken and analyzed at the start of the trial and 30 days later at the end of the supplementation period. Overall, patients in the fish oil groups experienced a significant decline in the number of abnormal cells in their colon lining as compared to members of the placebo group. Further analysis showed that the reduction in the number of abnormal cells was limited to patients who had a large number of abnormal cells at the beginning of the trial. The researchers also noted a very significant increase in EPA and DHA levels and a significant drop in arachidonic acid level in the biopsy samples from the fish oil supplemented patients.

A separate 6-month trial involving 15 patients taking 1.4 grams per day of EPA and 1.1 grams per day of DHA also showed a significant drop in the number of abnormal colon lining cells. The researchers conclude that low-dose supplementation with fish oils inhibit the proliferation of abnormal cells (a precursor to polyps) in patients at risk for colon cancer and that this effect can be maintained with long- term treatment. They caution that it may be advisable to increase vitamin E intake during fish oil administration.
Anti, Marcello, et al. Effects of different doses of fish oil on rectal cell proliferation in patients with sporadic colonic adenomas. Gastroenterology, Vol. 107, December 1994, pp. 1709-18

Fats and breast cancer
MILAN, ITALY. The association between the intake of various fats and oils and the risk of breast cancer has been the subject of several studies. There is still no real consensus as to which fats are beneficial and which are not. The evidence for a protective role of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main components of fish oils, is probably the strongest.
Researchers at the Italian National Cancer Institute have just completed an investigation aimed at clarifying the association between fat intake and breast cancer risk. A total of 4052 postmenopausal women were followed for an average of 5.5 years. During this time 71 cases of invasive breast cancer were diagnosed. The cancer patients were matched with 141 controls. All study participants had blood samples drawn and red blood cell (erythrocyte) membranes were analyzed for their fatty acid content. The researchers point out that erythrocyte membranes are good biomarkers for not only dietary fat intake, but also for other dietary and hormonal factors.
Women with DHA concentrations in the highest tertile had less than half the risk of breast cancer than did women in the lowest tertile. Polyunsaturated fatty acids overall were also protective with omega-3 acids being somewhat more protective than omega-6 acids. Saturated fatty acid concentrations were not significantly related to breast cancer risk. A higher concentration of monounsaturated fats, especially oleic acid, was associated with a significantly increased risk. The researchers point out that most oleic acid in mammalian tissue is derived from saturated stearic acid through a process involving the enzyme delta 9-desaturase. Saturated fatty acids, cholesterol, carbohydrates, insulin, testosterone, and estrogen all activate this enzyme whereas dietary polyunsaturated fatty acids and fasting deactivate it. The researchers conclude that the delta 9-desaturase enzyme may be an important link between breast cancer risk and dietary fat consumption and urge further research in the field.
Pala, Valeria, et al. Erythrocyte membrane fatty acids and subsequent breast cancer: a prospective Italian study. Journal of the National Cancer Institute, Vol. 93, July 18, 2001, pp. 1088-95

Fish consumption helps prevent prostate cancer
STOCKHOLM, SWEDEN. Several studies have shown an inverse relationship between blood levels of fish oils (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and the risk of prostate cancer. A study just completed by medical researchers at the Karolinska Institute confirms this association.
The Swedish study involved 3136 pairs of male twins born between 1886 and 1925. The participants completed food frequency questionnaires in 1961 and 1967 and were then followed up for 30 years. By December 31, 1997 the researchers had recorded 466 diagnoses of prostate cancer (340 fatal ones). The average age of diagnosis was 76.7 years. After adjusting for other known risk factors the researchers conclude that men who never eat fish have a two- to three-fold higher risk of prostate cancer than do men who eat moderate to high amounts. The researchers emphasize that only fatty fish such as salmon, herring and mackerel, which contain high amounts of omega-3 fatty acids (EPA and DHA), would be expected to be beneficial.
Terry, Paul, et al. Fatty fish consumption and risk of prostate cancer. The Lancet, Vol. 357, June 2, 2001, pp. 1764-66 (research letter)

Fish oils help prevent prostate cancer
AUCKLAND, NEW ZEALAND. Medical researchers in New Zealand provide convincing evidence that an increased consumption of fish oils helps reduce the risk of developing prostate cancer. Their study involved 317 men who had been diagnosed with prostate cancer during 1996-97 and 480 age-matched controls. Blood samples were obtained from all participants and the erythrocyte (red blood cell) phosphatidylcholine fraction of the plasma was analyzed for EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the two main components of fish oils.

Evaluation of the collected data showed a clear correlation between blood level of EPA and DHA and the presence of prostate cancer. Study participants with levels in the highest quartile were found to have a 40 per cent lower incidence than participants with levels in the lowest quartile. This relationship held true even when adjusted for age, height, use of NSAIDs (non-steroidal anti-inflammatory drugs), socio- economic status, and estimated intake of lycopene and polyunsaturated fats.

The researchers also found that men with low socio-economic status, a low intake of lycopene, and non- regular use of NSAIDs were more likely to develop prostate cancer. They did not, however, find any correlation between self-reported intake of EPA and DHA indicating that food frequency questionnaires are not an accurate method for estimating fish oil intake. The researchers speculate that fish oils may prevent the progression of prostate cancer by inhibiting the biosynthesis of eicosanoids from arachidonic acid.
Norrish, A.E., et al. Prostate cancer risk and consumption of fish oils: a dietary biomarker-based case-control study. British Journal of Cancer, Vol. 81, No. 7, December 1999, pp. 1238-42

Breast cancer risk linked to fatty acid profile
CHAPEL HILL, NORTH CAROLINA. Breast cancer rates differ greatly between countries. They are 5 times higher in the United States than in Japan and twice as high in France as in neighbouring Spain. Differences in overall fat consumption in these countries have been extensively studied, but no link to breast cancer incidence has been detected so far. A large team of researchers from the Netherlands, Ireland, Spain, Finland, Switzerland, Germany and the United States now report that, while overall fat consumption may not be significant, the make-up of the fats could be. As part of the large EURAMIC Study the researchers investigated the link between the content of polyunsaturated fats in adipose (fat) tissue of postmenopausal women and breast cancer incidence. A total of 291 women with breast cancer and 351 controls were included in the study which involved 5 European medical centers. The women all had samples of adipose tissue taken (from the buttocks) and analyzed to determine the concentration of the main polyunsaturated fatty acids: the omega-3 acids - alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the omega-6 acids - linoleic acid (LA) and its metabolite arachidonic acid (AA).

The study found no significant correlation between omega-3 fatty acid levels and breast cancer incidence, but did find a trend to increasing incidence with increasing levels of omega-6 fatty acids in the adipose tissue samples. The researchers also found a significant association between the ratio of EPA and DHA to LA levels and breast cancer incidence in 4 out of 5 of the medical centers involved in the study. Pooling all results showed that women with the highest ratio had a 35% lower breast cancer incidence than women with the lowest ratio. In other words, women with a relatively high adipose tissue level of EPA and DHA (the main components of fish oils) and a relatively low level of LA and its metabolites had a lower breast cancer risk. The researchers note that LA (linoleic acid) is the precursor of certain eicosanoids which may promote tumour growth. EPA and DHA inhibit the production of these harmful compounds and may also, on their own, inhibit tumour growth. The researchers also point out that several epidemiological studies have found an inverse correlation between fish consumption and breast cancer incidence and urge further studies to determine the relationship between the dietary intake of specific fatty acids and breast cancer risk.
Simonsen, Neal, et al. Adipose tissue omega-3 and omega-6 fatty acid content and breast cancer in the EURAMIC Study. American Journal of Epidemiology, Vol. 147, No. 4, 1998, pp. 342-52

ARTHRITIS

Fish oils help reduce arthritis symptoms
EPSOM, UNITED KINGDOM. Dr. Gail Darlington of the Epsom General Hospital and Dr. Trevor Stone of the University of Glasgow have just released a major paper reviewing the current state of the art in regards to diet and inflammatory diseases such as rheumatoid arthritis (RA). About 2% of the world's population suffers from RA and the disease is three times more prevalent among women than among men. RA can strike at any age and involves an inflammation of joint tissues associated with the release of toxic substances in the synovium that leads to cartilage destruction. The main symptoms are swelling of the affected joints, morning stiffness, fatigue and general malaise. There is considerable evidence now that RA is caused by oxidative stress and involves an excessive production of pro-inflammatory compounds like tumor necrosis factor-alpha and interleukin-1beta.

Research has shown that supplementation with fish oils (eicosapentaenoic acid and docosahexaenoic acid) can markedly reduce interleukin-1beta production and results in a significant reduction in morning stiffness and the number of painful joints in RA patients. Omega-6 polyunsaturated fatty acids (found in cooking oils and margarine), on the other hand, have been found to exacerbate RA symptoms. Fish oils have also been found useful in the management of systemic lupus erythematosus.

Drs. Darlington and Stone point out that long-term supplementation with fish oils may affect immune function and caution against daily intakes of more than 750 mg of EPA. (Editor's Note: Other studies have found intakes of 5 grams/day or more to be entirely safe for periods as long as seven years.) They also point out that fish oil supplements should contain at least 3 mg of vitamin E per gram of fish oil in order to avoid excessive peroxidation. [225 references]
Darlington, L. Gail and Stone, Trevor W. Antioxidants and fatty acids in the amelioration of rheumatoid arthritis and related disorders. British Journal of Nutrition, Vol. 85, March 2001, pp. 251-69

Fish oils recommended for rheumatoid arthritis
NEWCASTLE, AUSTRALIA. At least 13 published randomized, controlled clinical trials have reported significant benefits of fish oil supplementation in rheumatoid arthritis patients. Now researchers at the University of Newcastle weight in with the additional evidence to support these earlier findings. Their 15- week study involved 50 patients who had been diagnosed with rheumatoid arthritis. The patients were all consuming a diet which contained less than 10 grams/day of omega-6 fatty acids. These fats are known to promote inflammation through their eicosanoid metabolites. Half the patients were given fish oil capsules to provide a daily intake of 40 mg/kg body weight (about 2.8 grams for a 70 kg person); the other half received placebo capsules containing 50/50 corn/olive oil. All subjects continued with their regular diet and medications. About half the patients dropped out during the experiment, mainly due to changes in their medications. Complete clinical evaluations were carried out at baseline, 4, 8 and 15 weeks.

There were no significant changes after 4 or 8 weeks, but at the 15-week evaluation major improvements were noted in the group receiving fish oil. Particularly impressive were the improvements in the duration of morning stiffness and the overall assessment of disease activity (by both patients and physicians). Significant improvements were noted in 6 of the 9 evaluation parameters in the fish oil group; no improvements were noted in the control group. Only the total number of joints affected, the erythrocyte sedimentation rate (ESR), and the C-reactive protein level were unaffected by supplementation.

In an accompanying editorial Drs. Cleland and James of the Royal Adelaide Hospital emphasize the importance of maintaining a low intake of omega-6 fatty acids in order to keep the ratio of omega-6 to omega-3 as low as possible. They conclude that "dietary fish oil supplements should now be regarded as part of standard therapy for rheumatoid arthritis".
Volker, Dianne, et al. Efficacy of fish oil concentrate in the treatment of rheumatoid arthritis. Journal of Rheumatology, Vol. 27, October 2000, pp. 2343-46
Cleland, Leslie G. and James, Michael J. Fish oil and rheumatoid arthritis: antiinflammatory and collateral health benefits. Journal of Rheumatology, Vol. 27, October 2000, pp. 2305-06 (editorial)

Borage and fish oils go together
JACKSONVILLE, FLORIDA. Supplementation with gamma-linolenic acid (GLA) found in borage and evening primrose oils reduces the symptoms of chronic inflammatory diseases such as rheumatoid arthritis and atopic dermatitis. It is believed that the transformation of GLA to DGLA (dihomo-gamma- linolenic acid) in the inflammatory cells (white blood cells) helps dampen the inflammatory effects of AA (arachidonic acid). Unfortunately, there is a fly in the ointment. While GLA supplementation results in a decrease in AA in the inflammatory cells it also causes, somewhat paradoxically, a very significant increase in AA in the blood serum itself. A high blood level of AA is associated with an increased risk of blood clotting and is a potent risk factor for heart disease.

Researchers at the Mayo Clinic now report that the potentially harmful effects of GLA supplementation can be eliminated by simultaneous supplementation with fish oil. Their small clinical trial involved a control group of 2 healthy men and 2 healthy women who consumed a controlled diet while supplementing with 3 grams/day of GLA (5 capsules of borage oil morning and evening). The active treatment group (5 women and 7 men) followed the same protocol with the addition of 3 grams/day of EPA (eicosapentaenoic acid) taken in the form of 5 capsules of concentrated fish oil (each capsule containing 600 mg of EPA and 280 mg of DHA (docosahexaenoic acid). After 3 weeks of supplementation samples of white blood cells and samples of blood serum were analyzed to determine fatty acid profiles. Both groups experienced a marked increase in beneficial DGLA in their white blood cells. The control group (GLA supplementation only) also saw a significant increase in detrimental AA in their blood serum, but no such increase was observed in the group taking fish oil as well.

The researchers conclude that the detrimental effects of GLA supplementation can be avoided by adding fish oils to the supplementation regimen.
Barham, J. Brooke, et al. Addition of eicosapentaenoic acid to gamma-linolenic acid: supplemented diets prevent serum arachidonic acid accumulation in humans. Journal of Nutrition, Vol. 130, 2000, pp. 1925-31

Fish oils and rheumatoid arthritis
BADALONA, SPAIN. Several studies have shown that supplementation with n-3 polyunsaturated fatty acids (n-3 PUFAs) found in fish oils is beneficial for rheumatoid arthritis (RA) patients. Spanish medical researchers now report that RA patients tend to have decreased levels of n-3 PUFAs in their blood and synovial (joint) fluid. Their study involved 24 female and 15 male RA patients (median age of 64 years). Blood and joint fluid samples were collected from the patients and from a control group consisting of 28 healthy volunteers (17 male and 11 female with a median age of 61 years). All samples were analyzed to determine their fatty acid profile. RA patients were found to have significantly lower levels of eicosapentaenoic acid (the main component of fish tissue oil) in both their blood plasma and synovial fluid. The level of alpha-linolenic acid was lower in the synovial fluid of RA patients, but not in their blood plasma. The level of docosahexaenoic acid (a major component of fish tissue oil) also tended to be lower in synovial fluids of RA patients, but not in their blood plasma.

The researchers conclude that RA patients have an abnormal fatty acid profile and a significant deficiency in certain essential fatty acids. They believe this finding may explain why supplements such as fish oils and gamma-linolenic acid (from evening primrose and borage) have been found to be beneficial in the treatment of rheumatoid arthritis.
Navarro, Elisabet, et al. Abnormal fatty acid pattern in rheumatoid arthritis - A rationale for treatment with marine and botanical lipids. Journal of Rheumatology, Vol. 27, February 2000, pp. 298-303

Fish oils relieve rheumatoid arthritis
ALBANY, NEW YORK. Rheumatoid arthritis is a systemic inflammatory disease involving an excessive release of leukotriene B4 and interleukin 1 in the body. Both animal experiments and human studies have shown that supplementation with fish oils reduces the release of these inflammatory compounds and in the process relieves the common arthritis symptoms of morning stiffness and tender joints. Dr. Joel Kremer of the Albany Medical College has summarized the current knowledge concerning fish oils and rheumatoid arthritis and concludes that taking 3-6 grams daily of fish oils (n-3 dietary fatty acids) for 12 weeks or more will significantly diminish joint pain and morning stiffness in RA patients. Several studies have shown that the improvement in some patients is significant enough to allow them to materially reduce or completely discontinue their use of non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac and naproxen. Dr. Kremer also points out that fish oil supplementation has been found to benefit patients with inflammatory bowel disease.
Kremer, Joel M. n-3 fatty acid supplements in rheumatoid arthritis. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 349S-51S

Fish oils benefit rheumatoid arthritis patients
BOSTON, MASSACHUSETTS. Many small studies have concluded that fish oil supplementation leads to a marked improvement in rheumatoid arthritis symptoms. However, precisely because these studies have been small their publication has not had a major impact on the medical treatment of arthritis. A team of researchers from the Harvard Medical School has now combined and analyzed the results of these smaller studies. Their meta-analysis covered 10 double-blind, randomized, placebo-controlled studies aimed at determining the effect of fish oil supplementation on 8 measures of arthritis severity including the number of tender joints, number of swollen joints, extent of morning stiffness, grip strength, erythrocyte sedimentation rates, and overall global assessment of disease severity. The studies involved a total of 368 participants who took fish oil supplements for at least three months. The meta-analysis revealed a highly significant decrease in the number of tender joints and a significant shortening in the duration of morning stiffness among patients supplementing with fish oils. No statistically significant changes were observed for the other measured indicators of disease severity.
Fortin, Paul R., et al. Validation of a meta-analysis: the effects of fish oil in rheumatoid arthritis. Journal of Clinical Epidemiology, Vol. 48, 1995, pp. 1379-90

Fish oil may replace NSAIDs in some RA patients
ALBANY, NEW YORK. There is considerable evidence that fish oil supplementation can alleviate the symptoms of rheumatoid arthritis (RA). What is less clear is how much is required and whether fish oils are effective enough to eliminate the need for non-steroidal anti-inflammatory drugs (NSAIDs). Researchers at the Albany Medical College have released the results of a study which throws light on both of these questions.

The double-blind, placebo-controlled study involved 66 patients with active RA as indicated by the presence of at least 3 of the following symptoms:

6 or more tender joints;
3 or more swollen joints;
30 minutes or more of morning stiffness;
a sedimentation rate of 28 mm/hour or higher.

The patients were weaned off their current anti-inflammatory medications and were then started on the NSAID diclofenac (75 mg twice a day). After 2 weeks they were randomized into 2 groups receiving 130 mg/kg per day of either fish oil (EPA+DHA ethyl esters) or corn oil (an omega-6 fatty acid). The daily dose of fish oil corresponds to about 9 grams/day for a person weighing 70 kg. After 18 or 22 weeks the diclofenac was replaced by a placebo and the fish and corn oil supplementation continued for another 8 weeks after which all patients were switched to the corn oil plus diclofenac placebo until the end of the study at week 48.

The researchers found that the fish oil group achieved a significant lessening of their symptoms from the start of supplementation and until the replacement of diclofenac with the placebo. No statistically significant benefits were observed in the corn oil group. Several patients in the fish oil group maintained their improved status even after diclofenac withdrawal. The researchers conclude that some RA patients using fish oil supplementation may be able to discontinue NSAIDs without experiencing a flare-up of their disease. They also noted that the benefits achieved from supplementing with 9 grams/day of fish oil were no greater than those observed in other studies using only 3 to 6 grams/day.
Kremer, Joel M., et al. Effects of high-dose fish oil on rheumatoid arthritis after stopping nonsteroidal antiinflammatory drugs. Arthritis & Rheumatism, Vol. 38, August 1995, pp. 1107-14

Long-term fish oil supplementation benefits RA patients
LEUVEN, BELGIUM. Belgian researchers have released the results of a major study aimed at determining the long-term effects of fish oil supplementation in rheumatoid arthritis patients. Sixty patients completed the year-long, double-blind, randomized study. The participants were divided into 3 groups with 1 group receiving a daily supplement of 6 capsules containing 1 gram of olive oil each (placebo); another group receiving 3 olive oil capsules plus 3 fish oil capsules (containing 1 gram of fish oil each); and the third group receiving 6 fish oil capsules daily (corresponding to 2.6 grams/day of omega-3 fatty acid). All patients continued on their regular arthritis medications.

Three months into the study it became clear that the patients on fish oil alone had improved considerably when compared to the other 2 groups and this improvement became even more pronounced after 12 months of supplementation. Fifty-three per cent of the patients in the fish oil group showed significant overall (global) improvement as compared to 10% in the placebo group and 33% in the fish oil plus olive oil group. Forty-seven per cent of the patients in the fish oil group were also able to reduce their intake of NSAIDs and disease-modifying anti-rheumatic drugs as compared to 15% in the placebo group and 29% in the olive oil plus fish oil group. The researchers conclude that long-term supplementation with fish oils benefits rheumatoid arthritis patients significantly and may lessen their need for NSAIDs and other RA medications.
Geusens, Piet, et al. Long-term effect of omega-3 fatty acid supplementation in active rheumatoid arthritis. Arthritis & Rheumatism, Vol. 37, June 1994, pp. 824-29

Fish oil and margarine don't go together
ADELAIDE, AUSTRALIA. Fish oil supplements containing EPA (eicosapentaenoic acid) have an anti- inflammatory effect and may benefit people suffering from rheumatoid arthritis and psoriasis. This beneficial effect is significantly reduced when the diet is high in linoleic acid. A seven week controlled experiment involving 30 male volunteers was recently completed in Australia. The participants were given 1.6 gram EPA and 0.32 gram DHA (docosahexaenoic acid) daily. Half the volunteers were kept on a diet high in linoleic acid by using margarine as a spread and polyunsaturated oils for cooking. The other half used butter and olive oil which are low in linoleic acid. The experiment clearly showed that the incorporation of fish oil is enhanced by a diet containing butter and fish oil. Margarine and polyunsaturated oils had an inhibiting effect and should therefore be excluded from the diet in order to obtain maximum benefit from fish oil.
Cleland, Leslie G., et al. Linoleate inhibits EPA incorporation from dietary fish-oil supplements in human subjects. American Journal of Clinical Nutrition, Vol. 55, February 1992, pp. 395-99

Fish oils alleviate rheumatoid arthritis symptoms
ALBANY, NEW YORK. Rheumatoid arthritis is believed to involve an overactivity of certain inflammatory agents derived from arachidonic acid. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main components of fish oils, are known to inhibit the formation of these inflammatory agents. Research has shown that fish oil supplementation is beneficial in alleviating the symptoms of several inflammatory diseases.

Researchers at the Albany Medical College and the State University of New York now report that fish oils are quite effective in relieving the symptoms of rheumatoid arthritis. Their study involved 33 arthritis patients (25 women and 8 men) aged between 23 and 74 years who had suffered from arthritis for more than 3 years. Half the patients were assigned to supplement daily with 15 fish oil capsules (containing a total of 2.7 grams EPA and 1.8 grams DHA) while the other half received 15 placebo capsules every day (containing olive oil). After 14 weeks of supplementation and a 4-week wash-out period during which everyone took placebo capsules the group on fish oil switched to placebos and vice versa for a further 14 weeks. After 14 weeks on fish oil there was a very noticeable decrease in the average number of tender joints among the patients (from 9 to 5.5) and a 2.5-hour increase in the time to the first onset of fatigue after getting up in the morning. Although not statistically significant a trend to a shorter duration of morning stiffness and fewer swollen joints were also observed.

The researchers conclude that fish oil supplementation relieves arthritis symptoms, but point out that at least 12 weeks of fish oil ingestion is required before the benefits are felt.
Kremer, Joel M., et al. Fish-oil fatty acid supplementation in active rheumatoid arthritis: A double-blinded, controlled, crossover study. Annals of Internal Medicine, Vol. 106, April 1987, pp. 497-503

Fish diet helps patients with Crohn's disease

OTSU, JAPAN. Crohn's disease is an inflammatory disease involving intestinal pain, diarrhea, and malabsorption of nutrients. The disease is characterized by periods of active disease interspersed with periods of remission. Elemental diet (ED) therapy is the preferred treatment in Japan. Conventional treatment with prednisone and salycylates has been only marginally successful in extending the periods of remission. The ED therapy involves tube feeding (enteral nutrition) a mixture of free amino acids, short-chain maltodextrins, and low levels of fat in the form of soybean oil. Not surprisingly, compliance with this diet is poor resulting in shorter periods of remission.

Medical researchers at the Shiga University of Medical Science now report that one of the three daily enteral meals can be replaced by a special meal eaten normally. This new CD (Crohn's disease) diet consists of rice, cooked fish, and soup. It is rich in polyunsaturated fatty acids and has an omega-3 to omega-6 ratio of only 0.5. The researchers tried out the new diet regimen on 20 patients with Crohn's disease who had been using enteral ED therapy for over a month. The patients were allowed to eat the CD diet for lunch or dinner and continued with the ED regimen for the other 2 meals. They were also given nutritional education to emphasize the importance of following the diets. The results were very encouraging. Prior to the introduction of the CD diet 9 out of 10 patients experiences a relapse within one year; on the new regimen only 4 out of the 10 had a flare-up within one year. The researchers conclude that the combination ED and CD diet along with nutritional education is effective in extending the remission periods in Crohn's disease. They also point out that the inclusion of the CD diet prevents the development of nutritional deficiencies often seen in patients on the elemental diet alone.
Tsujikawa, Tomoyuki, et al. Clinical importance of n-3 fatty acid-rich diet and nutritional education for the maintenance of remission in Crohn's disease. Journal of Gastroenterology, Vol. 35, 2000, pp. 99-104

Fish oils give hope to patients with Crohn's disease
BOLOGNA, ITALY. Crohn's disease is characterized by periods of active disease interspersed with periods of remission. Now researchers at the University of Bologna report that fish oils prevent relapses. Their experiment involved 78 patients with Crohn's disease who had been classified as having a high risk of relapse. Half the patients were randomized to receive nine fish oil capsules daily, the other half received nine placebo capsules daily. The fish oil capsules contained 500 mg of a marine lipid concentrate each (40 per cent eicosapentaenoic acid and 20 per cent docosahexaenoic acid) and provided a total of 2.7 grams of n-3 fatty acids per day. The capsules were enteric-coated so as to ensure that they dissolved in the small intestine instead of in the stomach and to minimize unpleasant side effects such as flatulence, heartburn, belching, and diarrhea. The results of the fish oil therapy were spectacular. While 69 per cent of the patients in the control group had a relapse during the one-year study period, only 28 per cent in the therapy group did. At the end of the one-year period 59 per cent of the patients in the fish oil group were still in remission as compared to only 26 per cent in the placebo group. The researchers conclude that fish oil therapy (with enteric-coated capsules) is effective in preventing relapses in patients with Crohn's disease in remission. (NOTE: This study was supported in part by Tillotts Pharma of Switzerland, the manufacturer of the enteric-coated fish oil capsules).
Belluzzi, Andrea, et al. Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease. The New England Journal of Medicine, Vol. 334, No. 24, June 13, 1996, pp. 1557-60

Essential fatty acid deficiency and gastrointestinal disorders
BOSTON, MASSACHUSETTS. Researchers at the Boston University Medical Center report that patients with chronic gastrointestinal disorders have abnormal essential fatty acid profiles. Their study involved 25 patients with Crohn's disease, 11 with ulcerative colitis, 4 with celiac sprue, and 7 with short bowel syndrome. The patients and 56 non-obese healthy controls all provided fasting blood samples which were used to determine the fatty acid content of whole plasma. The researchers found that the patients tended to have significantly lower overall levels of saturated fat, monounsaturated fat, and polyunsaturated fat than did the controls. Their fatty acid profile was also shifted so that the percentage of polyunsaturated fat was lower than in the controls.

The researchers conclude that patients with inflammatory bowel diseases, sprue, and short bowel syndrome suffer from a deficiency of essential fatty acids. They believe this deficiency is not only a consequence of the disorder, but also contributes to it by interfering with the renewal and formation of new cells in the gut. They suggest that this deficiency needs to be corrected by adding omega-3 and/or omega-6 oils to the diet in the ratio required to eliminate the abnormalities. The researchers caution that some patients may not be able to metabolize the precursor omega-3 (alpha-linolenic acid) and omega-6 (linoleic acid) fatty acids and may need to be supplemented directly with the metabolites, eicosapentaenoic acid (EPA) and gamma-linolenic acid if needed, in the form of periodic intravenous infusions. [58 references]
Siguel, Edward N. and Lerman, Robert H. Prevalence of essential fatty acid deficiency in patients with chronic gastrointestinal disorders. Metabolism, Vol. 45, January 1996, pp. 12-23

Fish oils ameliorate ulcerative colitis

SAN FRANCISCO, CALIFORNIA. Ulcerative colitis, a common form of inflammatory bowel disease, is accompanied by an increased level of leukotriene B4 in the lining of the colon. Fish oils are known to inhibit the synthesis of leukotrienes and it has therefore been postulated that they might be beneficial in the treatment of ulcerative colitis. Researchers at the Veterans Affairs Medical Center have just released the results of a study aimed at testing this hypothesis.

The study involved 11 male patients aged 31 to 74 years who had been diagnosed with ulcerative colitis. The patients were randomized into two groups with one group receiving 15 fish oil capsules (providing 2.7 grams of eicosapentaenoic acid (EPA) and 1.8 grams of docosahexaenoic acid (DHA) daily); the other group received placebo capsules (olive oil). After 3 months on the supplements all participants underwent a 2-month wash-out period and were then assigned to the opposite treatment to what they had received during the first stage for another 3 months. Clinical evaluations of all patients were performed at the start of the study and every month thereafter.

Evaluation of the patients' clinical data at the end of the treatment periods showed a significant beneficial effect of fish oil supplementation. The mean disease severity score for the patients on fish oil declined by 56% as compared to 4% for the placebo group. Eight of the 11 patients (72%) were able to markedly reduce or totally eliminate their use of anti-inflammatory medication and steroids while taking the fish oils.

The researchers conclude that fish oil supplementation results in a marked clinical improvement of active mild to moderate ulcerative colitis.
Aslan, Alex and Triadafilopoulos, George. Fish oil fatty acid supplementation in active ulcerative colitis: A double-blind, placebo-controlled, crossover study. American Journal of Gastroenterology, Vol. 87, April 1992, pp. 432-37

Fish oils benefit patients with ulcerative colitis
NEW YORK, NY. Researchers at the Mount Sinai School of Medicine report that fish oil supplementation is highly effective in alleviating ulcerative colitis. Their small pilot study involved 10 patients with mild to moderate ulcerative colitis who had not been helped by conventional medical therapy. The patients were given 15 capsules of fish oil daily containing a total of 2.7 grams of eicosapentaenoic acid (EPA) and 1.8 grams of docosahexaenoic acid (DHA). The capsules were taken in 3 divided doses for an 8-week period. All patients underwent rigid sigmoidoscopy at entry to the study, at 4 weeks, and at the completion of the study. They also kept a daily log of the number of bowel movements, stool consistency, and any side effects. At the end of the 8 weeks 7 out of the 10 patients showed marked to moderate improvement and 4 out of 5 patients on prednisone were able to reduce their daily dose by 20 to 66%.

The researchers speculate that the EPA in the fish oil interferes with the synthesis of the highly inflammatory leukotriene B4 in the lining of the colon and that this effect accounts for the improvement. They recommend a large, randomized, placebo-controlled, double-blind trial to confirm the beneficial effects of fish oil supplementation in ulcerative colitis patients.
Salomon, Peter, et al. Treatment of ulcerative colitis with fish oil n-3-omega fatty acid: an open trial. Journal of Clinical Gastroenterology, Vol. 12, No. 2, 1990, pp. 157-61

Fish oils in treatment of psoriasis

GIESSEN, GERMANY. Psoriasis is a fairly common skin disease characterized by thick, silvery white scales surrounded by a red, inflamed border. Psoriasis is accompanied by high concentrations of arachidonic acid in the plaques and profound changes in the metabolism of eicosanoids leading to an increase in proinflammatory agents. It is known that eicosapentaenoic acid (EPA) counteracts the formation of these proinflammatory agents and some studies have shown that oral supplementation with fish oils benefits psoriasis patients.

A team of researchers from Austria, the Czech Republic, the Slovak Republic, Germany, and Poland now report that intravenous infusions of a fish oil emulsion is quite effective in ameliorating the symptoms of chronic plaque-type psoriasis. Their double-blind, randomized, placebo-controlled, multicenter trial involved 54 men and 29 women between the ages of 18 and 80 years who had been hospitalized with severe psoriasis. The patients were randomized into two groups. Group 1 (43 patients) received twice daily infusions of a fish oil emulsion (100 ml of a 10% emulsion infused over a period of 90 minutes) while group 2 (40 patients) received twice daily infusions of a placebo emulsion based on linoleic acid. The severity of the psoriasis was assessed by physicians on days 0, 4, 7, 11 and 15 of the two-week trial. Sixteen of the 43 patients (37%) receiving fish oil showed at least a 50% improvement in their condition at the end of the trial as compared to 9 out of 40 patients (23%) in the placebo group.

The researchers conclude that intravenous administration of a fish oil emulsion is safe and effective in the treatment of chronic plaque-type psoriasis and plan further work to determine if once daily infusions would be equally effective. NOTE: This study was funded in part by Fresenius AG, a manufacturer of fish oil emulsions.
Mayser, Peter, et al. Omega-3 fatty acid-based lipid infusion in patients with chronic plaque psoriasis: results of a double-blind, randomized, placebo-controlled, multicenter trial. Journal of the American Academy of Dermatology, Vol. 38, April 1998, pp. 539-47

EPA and etretinate alleviate psoriasis symptoms
OTSU, JAPAN. Etretinate is a powerful drug used to treat skin disorders such as psoriasis. It can cause serious adverse effects when used in the regularly prescribed dose of about 1 mg/kg per day. Researchers at the Shiga University of Medical Science now report that a combination of eicosapentaenoic acid (EPA) and etretinate at a lower dose (0.3 - 0.5 mg/kg per day) works as well as the pure, high-dose and has significantly fewer side effects. Their clinical trial included 40 psoriasis patients who were randomly assigned to receive either 20 mg etretinate daily (in capsules) or 20 mg etretinate plus 1800 mg of EPA ethyl ester (in capsules). After 12 weeks the participants were examined to determine the extent of improvement. Forty-five per cent of the patients in the combination group showed excellent improvement (greater than 75%) as compared to 15% in the pure etretinate group. The time to achieve a 50% improvement in symptoms was also considerably shorter in the combination group (5.1 weeks) than in the monotherapy group (7.6 weeks). Adverse reactions such as inflammation of the lips, dry mouth and eyes, and scaling were observed in both groups, but were mild and tolerable. The researchers conclude that the combination regimen is effective in the treatment of psoriasis without marked adverse reactions.
Danno, Kiichiro and Sugie, Nobuo. Combination therapy with low-dose etretinate and eicosapentaenoic acid for psoriasis vulgaris. Journal of Dermatology, Vol. 25, 1998, pp. 703-05

Topically applied fish oil alleviates psoriasis
BUENOS AIRES, ARGENTINA. Itching, scaling, and erythema (abnormal flushing of the skin) are common features of psoriasis, a fairly common skin disorder. One of the main characteristics of psoriasis is an increased concentration of arachidonic acid and its metabolite, leukotriene B4, in and around psoriatic plaque. It is well-established that fish oils suppress the formation of leukotriene B4 so researchers at the University of Buenos Aires Faculty of Medicine decided to investigate whether topical application of fish oil to skin areas affected by psoriasis would alleviate the symptoms. Their clinical trial involved 25 patients with psoriasis who were randomly assigned to apply either fish oil or liquid paraffin to their psoriatic plaques and leave them covered for 6 hours overnight under an occlusive dressing. The treatment was repeated daily for a 4-week period. Fish oil proved highly effective in reducing scaling (severity of scaling went from an average rating of 2.91 to 0.32 on a scale from 0 to 4), plaque thickness (from a rating of 2.21 to 0.52), and erythema (from a rating of 2.71 to 0.90). Itching was not relieved by the fish oil treatment. The 4-week liquid paraffin treatment was also effective in reducing erythema, but was significantly inferior to the fish oil treatment in reducing scaling and had no significant effect on itching or plaque thickness. Both treatments were well accepted by the patients and the researchers conclude that they are both clinically effective with the fish oil treatment being superior to the paraffin treatment.
Escobar, S.O., et al. Topical fish oil in psoriasis: a controlled and blind study. Clinical and Experimentology Dermatology, Vol. 17, 1992, pp. 159-62

Fish oil and margarine don't go together
ADELAIDE, AUSTRALIA. Fish oil supplements containing EPA (eicosapentaenoic acid) have an anti-inflammatory effect and may benefit people suffering from rheumatoid arthritis and psoriasis. This beneficial effect is significantly reduced when the diet is high in linoleic acid. A seven week controlled experiment involving 30 male volunteers was recently completed in Australia. The participants were given 1.6 gram EPA and 0.32 gram DHA (docosahexaenoic acid) daily. Half the volunteers were kept on a diet high in linoleic acid by using margarine as a spread and polyunsaturated oils for cooking. The other half used butter and olive oil which are low in linoleic acid. The experiment clearly showed that the incorporation of fish oil is enhanced by a diet containing butter and fish oil. Margarine and polyunsaturated oils had an inhibiting effect and should therefore be excluded from the diet in order to obtain maximum benefit from fish oil.
Cleland, Leslie G., et al. Linoleate inhibits EPA incorporation from dietary fish-oil supplements in human subjects. American Journal of Clinical Nutrition, Vol. 55, February 1992, pp. 395-99

Fish oils reduce psoriasis symptoms
SHEFFIELD, UNITED KINGDOM. Psoriasis is a relatively common skin disorder that affects between one and two per cent of the population. Itching, scaling, and erythema (abnormal flushing of the skin) are common features. Abnormal levels of leukotrienes (metabolites of arachidonic acid) are believed to be involved in the development and progression of the disorder. Eicosapentaenoic acid (EPA), a major component of fish oils, is known to dampen the adverse effects of leukotrienes and has been proven to have significant anti-inflammatory effects.

Medical doctors at the Royal Hallamshire Hospital have just released the results of a clinical trial designed to evaluate the effects of oral supplementation with fish oils in the treatment of psoriasis. The 28 patients involved in the trial had all been diagnosed with chronic psoriasis. They were randomized into two groups with one group receiving 10 fish oil capsules (containing 1.8 grams of EPA) and the other group receiving 10 olive oil capsules every day for the duration of the 12-week trial. After 8 weeks of treatment there was a significant reduction in itching, erythema and scaling in the fish oil group and a trend towards a decrease in the surface area of skin affected by the disease. No significant changes occurred in the placebo group. The researchers conclude that fish oil supplementation is useful in the treatment of psoriasis particularly when itching is a major problem.
Bittiner, S.B., et al. A double-blind, randomised, placebo-controlled trial of fish oil in psoriasis. The Lancet, February 20, 1988, pp. 378-80

Fish oils help asthma patients

LARAMIE, WYOMING. Asthma is an increasingly common affliction in the Western world. It is estimated that between 20 and 25 per cent of all children suffer from one or more symptoms of asthma at some point. There is evidence that a high dietary intake of linoleic acid (n-6 PUFA) may exacerbate asthma symptoms. Linoleic acid is found in particularly high concentrations in vegetable oils such as safflower, sunflower, and corn oils. Researchers at the University of Wyoming now report that adjusting the dietary intake of polyunsaturated fatty acids (PUFAs) may be effective in reducing asthma symptoms in many patients. Their experiment involved 26 non-smoking asthma-sufferers aged 19 to 25 years. The normal dietary intake of n-6 PUFA was determined for all participants at the start of the study and after one month. For the first month participants were given fish oil capsules containing enough EPA and DHA to adjust their intake ratio of n-3 PUFAs (fish oils) to n-6 PUFAs to 0.1:1. During the second month the participants had their n-3 PUFA to n-6 PUFA ratio adjusted to 0.5:1. The average fish oil intake required to produce the 0.5:1 ratio was 3.3 grams per day. Extensive testing showed that more than 40 per cent of the participants experienced a significant improvement in their breathing ability and better resistance to asthma attacks while on the high fish oil diet. The researchers conclude that dietary supplementation with fish oils or other enriched sources of n-3 PUFAs may be a viable therapy for asthma.
Broughton, K. Shane, et al. Reduced asthma symptoms with n-3 fatty acid ingestion are related to 5- series leukotriene production. American Journal of Clinical Nutrition, Vol. 65, April 1997, pp. 1011- 17

Oily fish protects against childhood asthma
SYDNEY, AUSTRALIA. Researchers at the University of Sydney report that the regular consumption of oily fish is associated with a much reduced risk of developing asthma in childhood. Their study involved 574 children aged 8 to 11 years. The children's parents completed detailed questionnaires about the frequency of the intake of more than 200 foods for a one-year period. The children were evaluated for current asthma as defined by airway hyperresponsiveness and a tendency to wheeze with or without exercise. The researchers found that children who regularly consumed fresh, oily fish (such as mullet, orange roughy, Atlantic salmon or rainbow trout which contains more than two per cent fat) had a four times lower risk of developing asthma than did children who rarely or never ate oily fish. The risk reduction persisted even after adjustment for other risk factors such as parental asthma and smoking, early respiratory infections, race, and place of birth. Consumption of non-oily fish and canned fish was not associated with a reduced asthma risk. Fish oil contains the two omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The researchers speculate that EPA may prevent the development of asthma or reduce its severity by reducing airway inflammation and responsiveness. A very recent study suggests that long-term fish oil supplementation may reduce asthma severity.
Hodge, Linda, et al. Consumption of oily fish and childhood asthma risk. Medical Journal of Australia, Vol. 164, February 5, 1996, pp. 137-40

Fish oils improve lung function in asthma patients
PARIS, FRANCE. Asthma involves an inflammation of the airway (pharynx, larynx and lungs). Epidemiological studies have shown that populations with a high intake of fish oils have a lower incidence of inflammatory diseases such as asthma. French researchers have completed a small trial to see if oral fish oil supplementation would benefit asthma patients. A total of 12 allergic asthmatic patients who were routinely receiving inhaled salbutamol, steroid and sodium nedocromil therapy participated in the one- year randomized, double-blind trial. Half the patients received 1 gram of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) daily; the other half received a placebo. Participants were evaluated every month and lung function tests performed every three months. A significant improvement in lung function was observed among the patients in the fish oil group. Forced expiratory volume in 1 second (FEV1) increased by 23% after 9 months of supplementation. The researchers point out that the treatment was well-tolerated and urge large-scale, long-term trials to confirm their findings.
Dry, J. and Vincent, D. Effect of a fish oil diet on asthma: results of a 1-year double-blind study. Int Arch Allergy Appl Immunol, Vol. 95, 1991, pp. 156-57

Fish oils may protect against emphysema
MINNEAPOLIS, MINNESOTA. Researchers at the University of Minnesota report that smokers who eat fish regularly are much less likely to develop chronic obstructive pulmonary diseases such as chronic bronchitis and emphysema. They believe the protective effect is due to the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content of fish. Other studies have shown that fish oils have anti- inflammatory properties and benefit patients with rheumatoid arthritis and ulcerative colitis. The study included 8960 people, 55 per cent of which were former smokers and 45 per cent current smokers. The researchers found that present or former smokers who ate four servings of fish per week had about half the risk of developing chronic bronchitis as did smokers who only ate 0.5 serving or less per week. Heavy fish eaters had only one third the risk of getting emphysema as did smokers who ate little fish. Eating four servings of fish per week corresponds to a daily intake of about 480 mg of fish oils (EPA and DHA). The researchers conclude that a high dietary intake of fish oils (n-3 fatty acids) may protect cigarette smokers against chronic obstructive pulmonary diseases.
Shahar, Eyal, et al. Dietary n-3 polyunsaturated fatty acids and smoking-related chronic obstructive pulmonary disease. The New England Journal of Medicine, Vol. 331, No. 4, July 28, 1994, pp. 228- 33

Lung disease and fish oils - A review of the evidence
BOSTON, MASSACHUSETTS. The idea that fish and fish oils may protect against lung disease developed from early studies of the dietary habits of Greenland Eskimos. Dr. D.F. Horrobin hypothesized that the high content of omega-3 fatty acids in the Eskimo diet is at least partially responsible for the low prevalence of lung disease in this population group. This makes biological sense inasmuch as omega-3 fatty acids (notably from fish and fish oils) are known to inhibit the synthesis of the inflammatory eicosanoids involved in lung diseases.

Dr. Joel Schwartz, MD of the Harvard Medical School has just published a review of the evidence concerning omega-3 fatty acids and lung disease. Dr. Schwartz concludes that there is good evidence that a high intake of fish helps retard the age-related decline in lung capacity observed among both smokers and non-smokers. He also points out that one long term trial of fish oil supplementation in adult asthma patients showed significant benefits, but that shorter trials (less than 1 year) have not confirmed these findings. Two Australian studies have shown that consumption of fresh fish (particularly oily fish) protects children against wheezing and asthma. The evidence concerning cystic fibrosis is controversial. Some studies have shown that fish oil supplementation suppresses the formation of the inflammatory eicosanoids which are characteristic of cystic fibrosis; however, little or no clinical improvements are noted in these studies. Other studies have found a significant protective effect of fish and fish oil in regard to chronic bronchitis and emphysema (chronic obstructive pulmonary disease) especially among smokers.

Dr. Schwartz concludes that there is a good case for fish and fish oils being protective against the development of chronic lung diseases, but that more research is needed to establish conclusive proof of benefits.
Schwartz, Joel. Role of polyunsaturated fatty acids in lung disease. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 393S-96S

Hyperactive children lack essential fatty acids

WEST LAFAYETTE, INDIANA. Children suffering from attention-deficit hyperactivity disorder (ADHD) are inattentive, impulsive, and hyperactive. Researchers at Purdue University now report that hyperactive children have lower levels of key fatty acids in their blood than do normal children. Their experiment involved 53 boys aged 6 to 12 years of age who suffered from ADHD, but were otherwise healthy and 43 matched controls. Analyses showed that the boys with ADHD had significantly lower levels of arachidonic, eicosapentaenoic, and docosahexaenoic acids in their blood. The hyperactive children suffered more from symptoms associated with essential fatty acid deficiency (thirst, frequent urination, and dry hair and skin) and were also much more likely to have asthma and to have had many ear infections. The researchers conclude that ADHD may be linked to a low intake of omega-3 fatty acids (linolenic, eicosapentaenoic, and docosahexaenoic acids) or a poorer ability to convert 18-carbon fatty acids to longer more highly unsaturated acids. The researchers conclude that supplementation with the missing fatty acids may be a useful treatment for hyperactivity.
Stevens, Laura J., et al. Essential fatty acid metabolism in boys with attention-deficit hyperactivity disorder. American Journal of Clinical Nutrition, Vol. 62, No. 4, October 1995, pp. 761-68

Intravenous fish oil infusion safe for CF patients

NEW YORK, NY. Seriously ill cystic fibrosis (CF) patients cannot absorb fats and other nutrients properly and therefore often need infusions of essential fatty acids. These infusions are most often based on linoleic acid as many CF patients have been found to have a deficiency of this omega-6 fatty acid. There is now substantial evidence that long-chain omega-3 fatty acids found in fish oils can suppress inflammatory processes such as those involved in CF.

A team of American, Finnish, and German researchers completed a small clinical trial aimed at determining if it would be safe and effective to use a fish oil fortified emulsion in the intravenous feeding of CF patients. The trial involved 12 patients; 6 were given infusions of a lipid emulsion enriched with fish oils while the remaining 6 (control group) were given infusions of the standard linoleic acid-based emulsion. The fish oil emulsion contained 18.3% eicosapentaenoic acid (EPA), 27.6% docosahexaenoic acid (DHA), 12.7% oleic acid, and 2.5% linoleic acid. The standard emulsion contained 54.5% linoleic acid, 22.4% oleic acid, and 0% EPA and DHA. Both emulsions were administered daily (over a 4-hour period) for 1 month at a dose of 150 mg/kg of body weight. The researchers found no adverse effects on liver function or coagulation parameters and no toxic or allergic reactions in the patients receiving the fish oil emulsion. There was a tendency to improved lung function in the fish oil group and a tendency towards a worsening in the control group during the trial; however, these effects were not statistically significant. The researchers conclude that intravenous infusions of lipid emulsions containing fish oils are safe for CF patients. They urge additional, longer-term studies to determine if such infusions would be of clinical benefit.
Katz, David P., et al. The use of an intravenous fish oil emulsion enriched with omega-3 fatty acids in patients with cystic fibrosis. Nutrition, Vol. 12, No. 5, 1996, pp. 334-39

Fish oil helps cystic fibrosis victims
NEW SOUTH WALES, AUSTRALIA. Researchers at the University of Sydney have found that daily supplementation with fish oil capsules alleviates many of the symptoms of cystic fibrosis. Cystic fibrosis is a serious, inherited childhood disease which involves a malfunctioning of the body's mucus glands. An abnormally thick mucus is produced which clogs the lungs and results in breathing difficulties. Other symptoms include persistent cough and wheezing, repeated lung infections, and a failure to gain weight. Sixteen cystic fibrosis patients aged 12 to 26 took part in the experiment. Half the group received fish oil capsules providing 2.7 g of eicosapentaenoic acid (EPA) per day while the other half received identical olive oil capsules as a placebo. After six weeks of treatment the patients receiving EPA coughed up significantly less sputum, were breathing easier (both forced expiatory volume and vital capacity were up) and generally felt better. The Australian researchers believe that the EPA acts by modifying the role of leukotriene B4. Leukotriene B4 is thought to be the main culprit in the excessive inflammatory response to bacteria which characterizes cystic fibrosis.
Lawrence, R. and Sorrell, T. Eicosapentaenoic acid in cystic fibrosis: evidence of a pathogenesis role for leukotriene B4. The Lancet, Vol. 342, August 21, 1993, pp. 465-69

Cystic fibrosis and fish oils
GENT, BELGIUM. There is evidence that cystic fibrosis patients with high plasma phospholipid levels of omega-3 fatty acids have better lung function than patients with lower levels. Cystic fibrosis (CF) is, unfortunately, often accompanied by fat malabsorption so it is not clear whether oral fat supplementation with omega-3 fatty acids would benefit CF patients.

Researchers at the State University of Gent set up an experiment to see if CF patients are able to absorb omega-3s effectively by mouth. The trial involved 9 CF patients (4 females and 5 males) ranging in age from 7 to 20 years. All had been diagnosed with pancreatic insufficiency and had poor fat absorption despite supplementing with pancreatic enzyme preparations. The patients were assigned to receive either 6 fish oil capsules per day for a month followed by 6 placebo capsules for a month or 6 placebo capsules daily for a month followed by 6 fish oil capsules daily for a month. Each fish oil capsule contained 335 mg of salmon oil and 165 mg of commercial soy lecithin and provided 152 mg of omega-3 fatty acids. The placebo capsules contained 500 mg of pharmaceutical-grade liquid paraffin.

The researchers found that the CF patients who took fish oil showed a marked increase in their phospholipid levels of eicosapentaenoic acid [EPA] (increase of 327%) and docosahexaenoic acid [DHA] (increase of 215%). The levels of EPA and DHA returned to baseline 2 weeks after discontinuing supplementation. The researchers also noted that patients with low initial levels of EPA showed the greatest increase in EPA levels after supplementation. They conclude that oral supplementation with fish oil and lecithin is effective in increasing the levels of omega-3 fatty acids especially EPA and DHA in cystic fibrosis patients.
Christopher, Armand, et al. Increase of long chain omega-3 fatty acids in the major serum lipid classes of patients with cystic fibrosis. Ann Nutra Metab, Vol. 36, 1992, pp. 304-12

Fish consumption and pregnancy outcome

COPENHAGEN, DENMARK. Danish researchers report that women who consume fish or seafood once a week during the first 16 weeks of pregnancy have a 3.6 times lower risk of giving birth to a low birth weight (less than 2500 grams) or premature (born before 259 days) baby than do women who never consume fish or seafood. The study involved almost 9000 women who completed a food frequency questionnaire. The researchers found that women whose daily intake of fish was less than 15 grams, corresponding to a fish oil intake of 150 mg/day, were significantly more likely to give birth to a preterm or underweight baby than were women with higher intakes. They suggest that small amounts of fish oil may confer protection against preterm delivery and low birth weight.
Olsen, Sjurour Frooi and Secher, Niels Jorgen. Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study. British Medical Journal, Vol. 324, February 23, 2002, pp. 1-5

Maternal milk and DHA supplementation
MUNICH, GERMANY. Docosahexaenoic acid (DHA) is vital for the proper development of an infant's brain and retina. DHA must be supplied through mother's milk or infant formula as the infant itself is unable to synthesize it from other dietary sources such as flax oil. The DHA content of human milk varies from 0.05% in vegetarian women to 1.40% in Inuit women. An average level in omnivorous women is about 0.3% by weight. It is assumed that a mother's diet affects the composition of her breast milk, but no specific studies of the transfer of DHA to breast milk has been made so far.

Researchers at the Ludwig-Maximilian-Universitat now report that an increased dietary intake of DHA by a lactating woman results in a proportional increase in her breast milk. Their study involved 10 lactating women who between week 4 and 6 postpartum supplemented with either 200 mg of DHA per day or 200 mg of a corn/soy oil mixture (placebo oil). At the end of the 2 weeks the DHA content of the milk from the DHA-supplemented mothers had increased by 28% while the DHA content in the milk from the mothers in the placebo group had decreased by 25%. In other words, after 2 weeks the DHA content in the milk from DHA-supplemented mothers was almost twice as high as in the milk from the mothers in the placebo group. There were no significant differences in the amount of milk produced per day by the 2 groups. Editor's note: Supplementation with DHA would be particularly important for lactating mothers who are vegetarian.
Fidler, Natasa, et al. Docosahexaenoic acid transfer into human milk after dietary supplementation: a randomized clinical trial. Journal of Lipid Research, Vol. 41, September 2000, pp. 1376-83

Fish oil supplementation during pregnancy is safe
ADELAIDE, AUSTRALIA. There is still considerable controversy regarding the role of long chain omega- 3 polyunsaturated fatty acids (PUFAs) in infant development and little attention has been paid to the requirements of mothers for these nutrients. Two researchers at the University of Adelaide have just released a review of existing research findings concerning these subjects. One clinical trial found that women who supplemented with fish oil (1.5 grams eicosapentaenoic acid [EPA] and 1 gram docosahexaenoic acid [DHA] daily) from their 30th week of pregnancy extended the pregnancy by 4 days and gave birth to infants weighing an average of 100 grams more that infants born to mothers supplementing with placebos (olive oil). Other studies have failed to confirm these effects. A recent study found that DHA levels decrease rapidly in women after giving birth independent of whether they are breastfeeding or not. There is speculation that this relative DHA deficiency could be a major factor in postpartum depression, but clinical trials are needed to confirm this. The deficiency can be completely eliminated by supplementing with 200 to 400 mg/day of DHA. The evidence concerning the benefits of maternal DHA supplementation on infant development is inconclusive. One study found that infants with an adequate DHA status at 3 months of age scored better on a mental development test at age 1 year, but not at 2 years of age. The researchers conclude that there is no evidence that maternal DHA supplementation is harmful and that it may have subtle benefits to both mother and infant. However, further clinical trials are needed to verify this.
Makrides, Maria and Gibson, Robert A. Long-chain polyunsaturated fatty acid requirements during pregnancy and lactation. American Journal of Clinical Nutrition, Vol. 71 (suppl), 2000, pp. 307S- 11S

Formula-fed infants need DHA
TORONTO, CANADA. A team of researchers from Canada, Britain, and the USA emphasize the importance of ensuring that newborn infants get sufficient docosahexaenoic acid (DHA) in order to ensure optimal neural and visual development during the first 6 months of life. They point out that there is still controversy as to whether the required DHA can be synthesized by the infants themselves (from alpha- linolenic acid) or must be supplied by the diet - be it breast milk or infant formula.

The researchers reviewed numerous studies comparing the DHA status of breast-fed infants with that of formula-fed ones. They found that over the first 6 months of life DHA accumulates in the body of breast- fed infants at a rate of 10 mg/day with 48% of this accumulation occurring in the brain. They estimate that an intake of 20 mg/day of DHA is required to achieve this accumulation and point out that breast feeding supplies about 60 mg/day. They believe the seeming over-abundance of DHA in breast milk may be needed in order to provide for potentially increased losses during disease, infection, surgery, and other conditions adversely affecting the infants' metabolism.

On the other hand, formula-fed infants would seem to develop a serious deficiency of DHA if they are fed a formula which has not been fortified with DHA (usually in combination with arachidonic acid). Standard infant formulas contribute about 390 mg/day of alpha-linolenic acid so about 5.2% of this would have to be converted to DHA in order to produce the needed 20 mg/day. The researchers point out that there is no evidence at all that infants are able to achieve this conversion rate and speculate that the rate may be as much as 20 times lower than required. This conclusion is amply supported by the fact that formula-fed infants actually lose 993 mg of DHA over the first 6 months of life while breast-fed babies gain an average of 1882 mg. The accumulation of DHA in the brain of formula-fed infants is only half of that observed in breast-fed infants and while the liver in breast-fed infants gains 24 mg of DHA during the first 6 months the liver in formula-fed ones actually loses 136 mg.

The researchers conclude that feeding infants with a non-fortified formula will not provide the DHA provided by breast milk. They urge further work to determine whether a formula containing at least 0.2% DHA (providing 60 mg/day of DHA) will provide equivalent DHA accumulation to that of breast-fed infants.
Cunnane, Stephen C., et al. Breast-fed infants achieve a higher rate of brain and whole body docosahexaenoate accumulation than formula-fed infants not consuming dietary docosahexaenoate. Lipids, Vol. 35, January 2000, pp. 105-11

Docosahexaenoic acid fortifies breast milk
HOUSTON, TEXAS. Docosahexaenoic acid (DHA) is an important component of brain cell membranes; a deficiency during infancy has been linked to poorer brain development and a decline in visual acuity. DHA occurs naturally in breast milk, but is absent in most infant formulas. Surveys have shown that the DHA content in breast milk from American women tends to be lower than that in milk from women in most other countries. Researchers at the Baylor College of Medicine now report that the DHA content of breast milk can be increased by supplementing with DHA and that this higher DHA content is transferred to breast-fed infants. The study involved 26 pregnant women who planned to breast feed exclusively for at least eight weeks after giving birth. The women were randomly assigned to one of four groups and given a daily DHA supplement or placebo from two weeks after giving birth to eight weeks after giving birth. Group 1 received an algae-produced triacylglycerol with a high DHA content (providing less than 230 mg/day of DHA); group 2 consumed two high DHA content eggs (providing 170 mg/day of DHA); group 3 took a low EPA, high DHA fish oil (providing 260 mg/day of DHA); and group 4 (the control group) consumed two regular eggs daily (providing less than 35 mg/day of DHA).

All three forms of DHA supplements produced significant increases in the DHA content of the women's blood plasma (phospholipid phase) and breast milk. Consumption of two eggs per day over a six-week period was well tolerated by all participants and had no adverse effects on cholesterol or triglyceride levels. The DHA level in the blood plasma (phospholipid phase) of the breast-fed infants also increased significantly over the six-week supplementation period with the infants in groups 1 and 3 having the largest increases. NOTE: This study was supported by a grant from the Mead-Johnson Nutritional Group. [61 references]
Jensen, Craig L., et al. Effect of docosahexaenoic acid supplementation of lactating women on the fatty acid composition of breast milk lipids and maternal and infant plasma phospholipids. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 292S-99S

Infants need long-chain omega-3 fatty acids
KANSAS CITY, MISSOURI. It is well-established that human infants require an adequate supply of omega-3 and omega-6 long-chain polyunsaturated fatty acids for optimal growth and neural development. There is evidence that the need for omega-3 acids, particularly docosahexaenoic acid (DHA), is especially pronounced among pre-term infants. It has been suggested that these infants lack the ability to synthesize DHA from alpha-linolenic acid in sufficient amounts to ensure an adequate supply to the brain and retina. Several studies have shown that pre-term infants fed a formula with added DHA developed better visual acuity and retinal response to light and scored higher when evaluated for mental development. In term infants some studies, but not all, have found higher visual acuity and better problem-solving ability in infants fed a DHA-containing formula.

Dr. S.E. Carlson of the University of Missouri supports the idea of adding DHA to infant formulas, but cautions that his fortification should be balanced with an appropriate addition of long-chain omega-6 acids (arachidonic acid) in order to more closely approximate the composition of mother's milk.
Carlson, S.E. Long-chain polyunsaturated fatty acids and development of human infants. Acta Paediatr Suppl, No. 430, 1999, pp. 72-7

Your brain needs DHA

NEW YORK, NY. Dr. Barbara Levine, Professor of Nutrition in Medicine at Cornell University, sounds the alarm concerning a totally inadequate intake of DHA (docosahexaenoic acid) by most Americans. DHA is the building block of human brain tissue and is particularly abundant in the grey matter of the brain and the retina. Low levels of DHA have recently been associated with depression, memory loss, dementia, and visual problems. DHA is particularly important for fetuses and infants; the DHA content of the infant's brain triples during the first three months of life. Optimal levels of DHA are therefore crucial for pregnant and lactating mothers. Unfortunately, the average DHA content of breast milk in the United States is the lowest in the world, most likely because Americans eat comparatively little fish. Making matters worse is the fact that the United States is the only country in the world where infant formulas are not fortified with DHA. This despite a 1995 recommendation by the World Health Organization that all baby formulas should provide 40 mg of DHA per kilogram of infant body weight. Dr. Levine believes that postpartum depression, attention deficit hyperactivity disorder (ADHD), and low IQs are all linked to the dismally low DHA intake common in the United States. Dr. Levine also points out that low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. DHA is abundant in marine phytoplankton and cold-water fish and nutritionists now recommend that people consume two to three servings of fish every week to maintain DHA levels. If this is not possible, Dr. Levine suggests supplementing with 100 mg/day of DHA.
Levine, Barbara S. Most frequently asked questions about DHA. Nutrition Today, Vol. 32, November/December 1997, pp. 248-49

Mothers' fish oil supplementation benefits infants
PORTLAND, OREGON. Animal experiments have shown that monkeys born by mothers with low blood levels of docosahexaenoic acid (DHA) develop impaired vision. There is also evidence that premature human infants fed standard infant formulas (very low in DHA) have impaired visual function which can be improved significantly by adding fish oils to their formulas. All this adds to the growing evidence that DHA is essential for the proper development of the brain and retina in the fetus and infant.

Researchers at the Oregon Health Sciences University recently set out to answer the question "Do high intakes of DHA by pregnant women increase the DHA level in their newborn infants?" Their clinical trial involved 31 healthy, pregnant women 15 of whom were assigned to receive 2.6 grams/day of omega-3 fatty acid from fish (1.01 grams DHA/day) from their 26th to their 35th week of pregnancy. The remaining women served as controls. The fish oil supplement was taken as a combination of tinned sardines and fish oil capsules; either 1 half tin of sardines plus 7 fish oil capsules per day, 1 tin of sardines (3 3/4 oz) plus 3 fish oil capsules per day or 10 fish oil capsules (10 grams) per day. Blood samples were collected from mothers at entry to the study, monthly after entry and at delivery, and from the infants at delivery. The level of DHA in the red blood cells of supplemented mothers rose from 4.69% (of total fatty acids) at entry to 7.15% at the end of week 34 and then declined (as expected) to 5.97% at delivery. DHA increases in the blood plasma paralleled the increase in the red blood cells, but at a lower level. DHA levels in newborn infants differed greatly depending on whether the mothers had supplemented or not. Red blood cell levels in infants born by supplementing mothers were 35.2% higher than in the control infants and blood plasma levels were 45.5% higher (5.05% vs. 3.47%).

The researchers believe that supplementing pregnant mothers with fish oil may benefit brain and retinal development in their offspring particularly if born prematurely. They point out that supplementing from mid-pregnancy to the 34th week is perfectly safe and may reduce the incidence of preeclampsia (pregnancy-related high blood pressure) as well.
Connor, William E., et al. Increased docosahexaenoic acid levels in human newborn infants by administration of sardines and fish oil during pregnancy. Lipids, Vol. 31 (suppl), 1996, pp. S183- S87

Docosahexaenoic acid helps brain development
MILAN, ITALY. Researchers at the University of Milan report that infants whose formula contains long- chain polyunsaturated fatty acids [especially Docosahexaenoic acid (DHA)] have better brain development than children who do not receive DHA in their formula. The observation supports earlier findings that there is a direct correlation between the DHA concentration in the red blood cells of infants and their visual acuity. The researchers recommend that infants who are not breastfed be fed on a DHA- enriched formula. Breast milk already contains the fatty acids necessary for good brain development.
Agostoni, Carlo, et al. Docosahexaenoic acid status and developmental quotient of healthy term infants. The Lancet, Vol. 346, September 2, 1995, p. 638

Additional References

Birch, E.E., et al. Visual acuity and the essentiality of docosahexaenoic acid and arachidonic acid in the diet of term infants. Pediatric Research, Vol. 44, August 1998, pp. 201-09
Conclusion: Supplementation with DHA appears necessary for optimal development of the brain and eyes of formula-fed infants.
Auestad, N., et al. Visual acuity, erythrocyte fatty acid composition, and growth in term infants fed formulas with long chain polyunsaturated fatty acids for one year. Pediatric Research, Vol. 41, January 1997, pp. 1-10
Conclusion: There was no improvement in growth or visual function in healthy term infants feed formula supplemented with DHA for 12 months.
Carlson, S.E. and Werkman, S.H. A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until two months. Lipids, Vol. 31, January 1996, pp. 85-90
Conclusion: DHA-supplemented formula increases information processing speed in preterm infants.
Werkman, S.H., and Carlson, S.E. A randomized trial of visual attention of preterm infants fed docosahexaenoic acid until nine months. Lipids, Vol. 31, January 1996, pp. 91-7
Conclusion: Preterm babies fed DHA-enriched formula had more rapid information processing.
Makrides, M., et al. Fatty acid composition of brain, retina, and erythrocytes in breast- and formula- fed infants. American Journal of Clinical Nutrition, Vol. 60, August 1994, pp. 189-94
Conclusion: Breast-fed infants have higher DHA levels in their cortex than do formula-fed infants.
Carlson, S.E., et al. Visual-acuity development in healthy preterm infants: effect of marine-oil supplementation. American Journal of Clinical Nutrition, Vol. 58, July 1993, pp. 35-42
Conclusion: Fish oil-fortified formula improves visual acuity in preterm infants.
Hoffman, D.R., et al. Effects of supplementation with omega-3 long-chain polyunsaturated fatty acids on retinal and cortical development in premature infants. American Journal of Clinical Nutrition, Vol. 57 (suppl 5), May 1993, pp. 807S-12S
Conclusion: Fish oil-fortified formula improves visual and cortical function in preterm infants.
Hoffman, D.R. and Uauy, R. Essentiality of dietary omega-3 fatty acids for premature infants: plasma and red blood cell fatty acid composition. Lipids, Vol. 27, November 1992, pp. 886-95
Conclusion: Formula for preterm infants should be supplemented with omega-3 fatty acids including fish oils.
Birch, E.E., et al. Dietary essential fatty acid supply and visual acuity development. Invest Ophthalmol Vis Sci, Vol. 33, October 1992, pp. 3242-53
Conclusion: Fish oil-fortified formula improves visual acuity in preterm infant

Hyperactive children lack essential fatty acids

Attention-deficit disorder in adults

SUNBURY, OHIO. Attention-deficit hyperactivity disorder (ADHD) is characterized by hyperactivity, emotional instability, poor coordination, short attention span, poor concentration, impulsiveness, and learning disorders. It is very common among school-age children with an incidence of between four and twenty per cent. Dr. Eugene Arnold, MD, Professor of Psychiatry at Ohio State University, points out that ADHD is not just a childhood disorder, but can be found among adults as well. Dr. Arnold has just completed an exhaustive survey of alternative treatments for adult ADHD. Although none of these treatments have undergone strictly controlled clinical trials some of them may nevertheless be worth a try. Relaxation training, biofeedback, meditation and massage are safe therapies that may have benefits. Fish oil supplementation, vitamins and minerals (in RDA dosages), herbal and homeopathic remedies, laser acupuncture, and anti-fungal (Candida) therapy may also be of benefit. Thyroid dysfunction and chronic lead poisoning are possible causes of ADHD and should be investigated and treated if necessary. Chelation is effective in removing lead. Zinc and magnesium supplementation may be useful if a deficiency is present and St. John's wort (hypericum) should at least be given a pilot study according to Dr. Arnold.
Arnold, L. Eugene. Alternative treatments for adults with ADHD. Annals of the New York Academy of Sciences, Vol. 931, June 2001, pp. 310-41

Docosahexaenoic acid deficiency may be key to ADHD
WEST LAFAYETTE, INDIANA. It is estimated that 3-5% of the school-age population in the United States suffer from attention-deficit hyperactivity disorder (ADHD). Prominent symptoms of this disorder are a poor attention span, inability to complete tasks, hyperactivity, and a tendency to interrupt others. Almost one quarter of children with ADHD also suffer from one or more specific learning disabilities in math, spelling or reading.

A study first reported in 1995 linked ADHD to a deficiency of certain long-chain fatty acids. These acids (arachidonic, eiscosapentaenoic, and docosahexaenoic acids) are all metabolites of the two essential fatty acids, linoleic acid (omega-6) and alpha-linolenic acid (omega-3). Researchers at Purdue University are now leaning towards the conclusion that a subclinical deficiency in docosahexaenoic acid (DHA) is responsible for the abnormal behaviour of children with ADHD. They point out that supplementation with a long-chain omega-6 fatty acid (evening primrose oil) has been unsuccessful in ameliorating ADHD and believe this is because ADHD-children need more omega-3 acids rather than more omega-6 acids. The researchers also found that children with ADHD were breast fed less often as infants than were children without ADHD. Breast milk is an excellent source of DHA. A study is now underway to investigate the effect of oral supplementation with DHA on the behaviour of ADHD-children.
Burgess, John R., et al. Long-chain polyunsaturated fatty acids in children with attention-deficit hyperactivity disorder. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 327S- 30S

Fish oils may help dyslexic children

GUILDFORD, UNITED KINGDOM. Dyslexia is a fairly common condition which involves difficulties in learning to read and write, mirror reversals of letters and words, and poor short-term memory. Dyslexia is closely related to dyspraxia (problems with coordination and muscle control) and attention-deficit hyperactivity disorder. It is estimated that about 10% of the populations of the United States and the United Kingdom suffer from dyslexia and 4% are severely affected. There was a 3-fold increase in the prevalence of learning disorders in the USA over the period 1976 to 1993 and 80% of the new cases involved dyslexia.

Dr. Jacqueline Stordy of the University of Surrey believes that dyslexia, dyspraxia, and attention-deficit hyperactivity disorder have one common denominator - a deficiency of long-chain fatty acids. She points to a study which found improved dark adaptation (a problem among dyslexics) after supplementation with 480 mg/day of docosahexaenoic acid (a main constituent of fish oil) for a month. Another study involving 15 dyspractic children found that supplementation with a proprietary mixture of tuna oil, evening primrose oil, thyme oil, and vitamin E for 4 months markedly improved their motor skills. The mixture provided 480 mg of docosahexaenoic acid, 35 mg of arachidonic acid, 96 mg of alpha-linolenic acid, 80 mg of vitamin E, and 24 mg of thyme oil daily. Dr. Stordy concludes that long-chain polyunsaturated fatty acid supplements may benefit children with dyslexia, dyspraxia, and attention-deficit hyperactivity disorder and notes that large, double-blind, placebo-controlled studies are already underway to verify this hypothesis.
Stordy, B. Jacqueline. Dark adaptation, motor skills, docosahexaenoic acid, and dyslexia. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 323S-26S

Your brain needs DHA
NEW YORK, NY. Dr. Barbara Levine, Professor of Nutrition in Medicine at Cornell University, sounds the alarm concerning a totally inadequate intake of DHA (docosahexaenoic acid) by most Americans. DHA is the building block of human brain tissue and is particularly abundant in the grey matter of the brain and the retina. Low levels of DHA have recently been associated with depression, memory loss, dementia, and visual problems. DHA is particularly important for fetuses and infants; the DHA content of the infant's brain triples during the first three months of life. Optimal levels of DHA are therefore crucial for pregnant and lactating mothers. Unfortunately, the average DHA content of breast milk in the United States is the lowest in the world, most likely because Americans eat comparatively little fish. Making matters worse is the fact that the United States is the only country in the world where infant formulas are not fortified with DHA. This despite a 1995 recommendation by the World Health Organization that all baby formulas should provide 40 mg of DHA per kilogram of infant body weight. Dr. Levine believes that postpartum depression, attention deficit hyperactivity disorder (ADHD), and low IQs are all linked to the dismally low DHA intake common in the United States. Dr. Levine also points out that low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. DHA is abundant in marine phytoplankton and cold-water fish and nutritionists now recommend that people consume two to three servings of fish every week to maintain DHA levels. If this is not possible, Dr. Levine suggests supplementing with 100 mg/day of DHA.
Levine, Barbara S. Most frequently asked questions about DHA. Nutrition Today, Vol. 32, November/December 1997, pp. 248-49

Hyperactive children lack essential fatty acids
WEST LAFAYETTE, INDIANA. Children suffering from attention-deficit hyperactivity disorder (ADHD) are inattentive, impulsive, and hyperactive. Researchers at Purdue University now report that hyperactive children have lower levels of key fatty acids in their blood than do normal children. Their experiment involved 53 boys aged 6 to 12 years of age who suffered from ADHD, but were otherwise healthy and 43 matched controls. Analyses showed that the boys with ADHD had significantly lower levels of arachidonic, eicosapentaenoic, and docosahexaenoic acids in their blood. The hyperactive children suffered more from symptoms associated with essential fatty acid deficiency (thirst, frequent urination, and dry hair and skin) and were also much more likely to have asthma and to have had many ear infections. The researchers conclude that ADHD may be linked to a low intake of omega-3 fatty acids (linolenic, eicosapentaenoic, and docosahexaenoic acids) or a poorer ability to convert 18-carbon fatty acids to longer more highly unsaturated acids. The researchers conclude that supplementation with the missing fatty acids may be a useful treatment for hyperactivity.
Stevens, Laura J., et al. Essential fatty acid metabolism in boys with attention-deficit hyperactivity disorder. American Journal of Clinical Nutrition, Vol. 62, No. 4, October 1995, pp. 761-68

ADHD and essential fatty acids
AUCKLAND, NEW ZEALAND. Researchers at the School of Medicine at the University of Auckland released a fascinating report which throws a great deal of light on the question "Why are hyperactive children different from normal children"?

The study involved 48 hyperactive children and 49 age- and sex-matched controls. The hyperactive children were selected based on input from both teachers and parents and all participants were evaluated using four behaviour rating scales. The researchers discovered numerous, statistically significant differences between hyperactive and normally behaved children:

Hyperactive children had significantly lower birth weights and learned to walk later than normal children;
Hyperactive children were more likely to have frequent coughs and colds (44% vs. 8% among normal children);
52% of hyperactive children had an abnormal degree of thirst compared to only 6% in the control group;
Hyperactive children were more likely to have speech and language difficulties (32% vs. 6%) and difficulties in learning (67% vs. 6%).

Blood analyses showed that hyperactive children had significantly depressed levels of docosahexaenoic, dihomogammalinolenic, and arachidonic acids. Other research has found that hyperactive children also tend to have lower zinc levels. The researchers point out that male animals require 3 times as much EFAs (essential fatty acids) as do females in order to achieve normal neonatal and infant development; this is consistent with the finding that hyperactivity is far more common among boys than among girls. They also report that they carried out a double-blind, placebo-controlled, crossover study of supplementation with evening primrose oil in 31 selected hyperactive children. No benefits of the supplementation were observed. NOTE: This study was partially funded by Efamol Research Ltd., a manufacturer of evening primrose oil supplements.
Mitchell, E.A., et al. Clinical characteristics and serum essential fatty acid levels in hyperactive children. Clinical Pediatrics, Vol. 26, August 1987, pp. 406-11

Fish oils: A cure for depression?

WASHINGTON, DC. On a worldwide basis more working days are lost to depression than to any other illness. The incidence of depression is growing with people born within the last 50 years being twice as likely to suffer from it than were their parents. Dr. Joseph Hibbeln of the National Institutes of Health believes that the reason for the increase in depression can be directly attributed to a major shift in dietary patterns, specifically fat intake. He points out that the vast increase in the use of soy, corn, palm and cottonseed oils in the last 100 years has totally changed the traditional ratio of omega-6 to omega-3 fatty acids in the diet. Soy oil consumption in the US, for example, has increased thousand-fold in the last 100 years helping to skew the omega-6 to omega-3 ratio from about 1:1 to today's 16:1. This, Dr. Hibbeln believes, spells trouble. The brain consists pretty well entirely of fat so clearly one's fat intake could affect one's brain composition, particularly the ion channels which channel signals in and out of the brain. There is also evidence that low levels of omega-3 fatty acids are associated with low levels of the mood hormone serotonin. Dr. Hibbeln's hypothesis is supported by the fact that the incidence of depression is considerably lower in countries with a high fish consumption.
Fish, particularly fatty ocean fish, is an excellent source of omega-3 fatty acids and its frequent consumption would help to nudge the ratio back towards the optimum 1:1. At least three clinical trials have observed a marked improvement in depressed patients given relatively high doses of fish oils. This has spurred other scientists to look closer at the potential benefits of fish oil supplementation. At the moment there are at least 10 clinical trials underway evaluating fish oils in the treatment of depression, attention deficit disorder, and schizophrenia.
Small, Meredith F. The happy fat. New Scientist, August 24, 2002, pp. 34-37
Editor's comment: Daily supplementation with 1-3 grams of a high quality fish oil is entirely safe and may not only improve your mood, but help protect you from heart disease, stroke and arthritis as well.

Fish consumption reduces suicide risk

KUOPIO, FINLAND. Researchers at the University of Kuopio report that regular fish consumption reduces the risk of depression and suicide. Their study involved 1767 Finnish men and women who were evaluated for depression and suicidal tendencies using the 21-item Beck Depression Inventory. They were also asked about their fish consumption. The researchers conclude that people who consume fish twice a week or more have a 37 per cent lower risk of being depressed and a 43 per cent lower risk of having thoughts of harming themselves (suicidal tendencies).
The results are consistent with those of a large Japanese study involving 265,000 subjects who were followed up for 17 years. This study found a decreased risk of suicide among people who consumed fish daily. Dr. Andrew Stoll, MD of the Harvard Medical School points out that Icelanders who consume a lot of seafood have far lower rates of seasonal affective disorder (SAD) than do inhabitants of other countries situated at similar latitudes. Both Dr. Stoll and the Finnish researchers urge large-scale trials to conclusively determine whether it is appropriate to recommend increased fish intake or fish oil supplementation to depressed people or indeed to the population as a whole.
Tanskanen, Antti, et al. Fish consumption, depression, and suicidality in a general population. Archives of General Psychiatry, Vol. 58, May 2001, pp. 512-13

Dementia associated with low DHA levels

GUELPH, CANADA. Dementia now affects about 47% of the population over 80 years of age in Western countries. The incidence of Alzheimer's disease, a leading cause of dementia, is growing especially rapidly. There is no cure for Alzheimer's disease (AD) and it is not at all clear what causes it. Researchers at the University of Guelph now report that they have found low levels of long-chain polyunsaturated fatty acids, notably DHA (docosahexaenoic acid) in people suffering from AD and dementia.

The study involved 84 people (aged 80 years or older) who were given a thorough clinical evaluation. Nineteen of the people were diagnosed as having AD, 10 as having non-AD dementia, 36 were characterized as non-demented but cognitively impaired, and 19 had normal cognitive functioning. Blood samples were obtained from all participants and analyzed for fatty acids in the phospholipid phases of the plasma. The researchers observed significantly lower levels of EPA (by about 42%), DHA (by 17-33%) and total omega-3 fatty acids (by 23-28%) in the plasma phospholipids phase of the patients with AD, other dementia and cognitive impairment (non-demented) than in the normal controls. DHA is highly concentrated in the cerebral cortex and a deficiency in blood plasma is likely to translate into a deficiency in the brain.

Other research has confirmed the association between low DHA and EPA levels and impaired cognitive function. Other studies have found that fish oil supplementation improves mood, cooperation, appetite, sleep, and short-term memory in AD patients. The Guelph researchers conclude that an effort should be made to increase the intake of fish or fish oils in the population at large and the elderly in particular.
Conquer, Julie A., et al. Fatty acid analysis of blood plasma of patients with Alzheimer's disease, other types of dementia, and cognitive impairment. Lipids, Vol. 35, December 2000, pp. 1305-12

EPA cures schizophrenia

LONDON, UK. There is evidence that schizophrenia is associated with an abnormal metabolism of unsaturated fatty acids in both blood plasma and red blood cells. This abnormality, in turn, is associated with extraordinary low levels of long-chain unsaturated fatty acids such as EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and AA (arachidonic acid) in cell membranes.

Researchers at the Imperial College School of Medicine now report that fatty acid levels can be restored to normal and schizophrenia symptoms eliminated or at least vastly diminished by oral supplementation with EPA, the major component of fish oils. Their experiment involved a 30-year-old man who had suffered from schizophrenia for over 10 years. He had frequent (at least daily) hallucinations and also suffered from persecutory delusions and thought disorder. The patient was put on 2 grams/day of EPA and was evaluated for schizophrenia symptoms and blood plasma and red blood cell membrane levels of fatty acids at monthly intervals for 6 months. The results were spectacular. After 6 months the overall score for schizophrenia symptoms had dropped by a factor of 6 (an 85% reduction in severity). Episodes of delusions were completely eliminated and there was an 88% reduction in the number of hallucinatory episodes.

The remarkable clinical improvement in symptoms was associated with substantial increases in the levels of EPA, DHA and AA in red blood cell membranes and with significant increases in EPA and DHA levels in blood plasma. The researchers conclude that EPA supplementation is able to reverse the abnormal fatty acid profiles found in schizophrenics and that this reversal is associated with, and is likely to be the cause of, the clinical improvement.
Richardson, A.J., et al. Red cell and plasma fatty acid changes accompanying symptom remission in a patient with schizophrenia treated with eicosapentaenoic acid. European Neuropsychopharmacology, Vol. 10, 2000, pp. 189-93

Fish oil supplementation helps schizophrenia patients
OXFORD, UK. The Cochrane Library, a prestigious medical think-tank dedicated to the development of evidence-based medicine, has just released a review of the evidence concerning the use of polyunsaturated fatty acids (fish oils and evening primrose oil) in the treatment of schizophrenia. A wide- ranging literature survey revealed 4 studies that met the Library's stringent quality measures. The most recent study (Shah 2000) included 30 newly diagnosed schizophrenia patients who were not on antipsychotic drugs at the beginning of the trial. The patients were randomized to receive either a placebo or a daily dose of eicosapentaenoate (quantity not specified). At the end of the 12 weeks all the patients in the placebo group needed to be placed on antipsychotic drugs. Only 9 of the 15 patients in the active treatment group needed these drugs after the 12 weeks.

Another study (Peet 1997) compared evening primrose oil supplementation with placebo in 43 schizophrenics. The patients' mental state was not improved in either the placebo or the treatment group after 12 weeks. A third study involving 29 schizophrenics compared supplementation with fish oil to evening primrose oil and found fish oil superior.

The researchers conclude that fish oils may be useful in the treatment of schizophrenia and that medical doctors should not discourage their patients from taking fish oil supplements. They add that fish oils seem to be well tolerated and free of adverse effects.
Joy, CB, et al. Polyunsaturated fatty acid (fish or evening primrose oil) for schizophrenia. The Cochrane Library, Issue 4, 2000

Dieting and depression

TUCSON, ARIZONA. Low-fat diets have been widely promoted for lowering cholesterol levels, for reducing body weight, and for preventing certain types of cancer. At least one study, however, has found that although a reduction in cholesterol may reduce mortality from heart disease it may increase the incidence of fatal accidents, violent deaths, suicides, and depression. Researchers at the University of Arizona now believe that they may have found an explanation for this phenomenon. They point out that fat restriction and cholesterol-lowering drugs may change the concentrations of polyunsaturated fatty acids (PUFAs) in the tissues including nerve tissue (neurons). Fat-restricting diets usually lead to a relative increase in the intake of omega-6 PUFAs and a relative decrease in the intake of omega-3 fatty acids. This can have serious consequences inasmuch as the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oils, are crucial for the proper functioning of the nervous system. Several large-scale studies have found a clear association between low blood levels of EPA and DHA and an increased risk of depression, violence and suicide; a recent study in Japan found that DHA supplementation reduced aggression among healthy Japanese students.

Epidemiologic studies have found a clear correlation between a low intake of EPA and DHA and the prevalence of depression. In two studies of population groups in the USA the incidence of depression was found to be 3.7% and 2.9%. Average intake of EPA and DHA in the USA is estimated to be about 0.1 gram per day. In two Japanese studies, on the other hand, the incidence of depression was only 0.9% and 0% and the intake of EPA plus DHA was 1.5 grams per day and 4.2 grams/day respectively. Other studies have shown that on-off dieting can produce a serious imbalance in the ratio of fatty acids and may lead to depression

The researchers conclude that an extremely low-fat diet may be counter-productive and have deleterious psychological ramifications. They stress that dietary advice regarding cholesterol reduction, weight loss, and cancer prevention should emphasize the importance of an adequate intake of omega-3 fatty acids.
Bruinsma, Kristen A. and Taren, Douglas L. Dieting, essential fatty acid intake, and depression. Nutrition Reviews, Vol. 58, April 2000, pp. 98-108 [116 references]

Low docosahexaenoic acid levels and Alzheimer's disease

BOSTON, MASSACHUSETTS. Docosahexaenoic acid (DHA), a major component of fish oils, is the most important fatty acid in the brain and retina and makes up more than 30% of the structural lipid (fat) in neurons. There is ample evidence that a deficiency of DHA is associated with depression, attention deficit hyperactivity disorder, and dementia. Clinical studies have shown that an increased intake of DHA may benefit patients with dyslexia and Alzheimer's disease.

Researchers at Boston University and Tufts University School of Medicine now report that they have found a clear association between low blood levels (in the phosphatidylcholine fraction of serum) of DHA and the risk of developing Alzheimer's disease. Their study involved 1188 elderly Americans (mean age of 75 years) who had blood samples drawn and analyzed for DHA in 1985. Sixteen of the participants had clinically diagnosed Alzheimer's at the time of blood sampling. The researchers noted that 11 of the 16 (69%) had DHA levels in the lower half of the DNA distribution. The remaining 1172 participants were followed for 10 years. Again the researchers noted that participants with DHA levels in the lower half of the distribution had a 67% greater risk of developing Alzheimer's disease. The researchers suggest that maintaining adequate levels of DHA through the consumption of fish or dietary supplements rich in DHA may be particularly important for the elderly.
Kyle, D.J., et al. Low serum docosahexaenoic acid is a significant risk factor for Alzheimer's dementia. Lipids, Vol. 34 (suppl), 1999, p. S245

Fish oils and manic-depressive illness

BOSTON, MASSACHUSETTS. Manic-depressive illness (bipolar disorder) is a common, severe mental illness involving repeated episodes of depression, mania (rapid mood changes, hyperactivity, and excessive cheerfulness) or both. It is usually treated with drugs such as lithium carbonate or valproate. Unfortunately, these drugs are not very effective and recurrence rates are high. It is generally believed that bipolar disorder involves an overactivity in the neuronal signal pathways. Omega-3 fatty acids are known to dampen this overactivity and the hypothesis has been advanced that they may be useful in the treatment of bipolar disorder. Medical scientists have now confirmed this in a landmark study just completed at the Harvard Medical School.

The double-blind, placebo-controlled study involved 30 patients (men and women 18 to 65 years of age) who had all been diagnosed with bipolar disorder. Half the patients were given seven fish oil capsules twice a day while the placebo group were given seven olive oil capsules twice a day. Each fish oil capsule contained 440 mg of eicosapentaenoic acid and 240 mg of docosahexaenoic acid. All of the participants except four in the fish oil group and four in the placebo group also continued to receive a standard mood-stabilizing drug prescribed previously. The mental state of the participants was measured using four scales (Clinical Global Impression Scale, Global Assessment Scale, Young Mania Rating Scale, and the Hamilton Rating Scale for Depression) at the start of the study and after two, four, six, eight, twelve and sixteen weeks. Twelve of the 14 participants in the fish oil group completed the four- month study without major episodes of mania or depression as compared to only six out of 16 participants in the placebo group. Also, while nine of the placebo group members experienced worsening depression none of the fish oil group members did. The four patients in the fish oil group who had not been prescribed mood-stabilizing drugs all completed the study without major episodes, but only one member in the placebo group not on mood-stabilizing drugs did. The average decline in depression rating on the Hamilton Scale was almost 50 per cent in the fish oil group as compared to an increase of 25 per cent in the control group. The Harvard researchers urge further trials of fish oils in the treatment of depression and manic-depressive illness.
Stoll, Andrew L., et al. Omega 3 fatty acids in bipolar disorder. Archives of General Psychiatry, Vol. 56, May 1999, pp. 407-12 and pp. 415-16 (commentary)
Calabrese, Joseph R., et al. Fish oils and bipolar disorder. Archives of General Psychiatry, Vol. 56, May 1999, pp. 413-14 (commentary)

Fish consumption and depression
ROCKVILLE, MARYLAND. Dr. Joseph Hibbeln, a researcher at the National Institute on Alcohol Abuse and Alcoholism reports in a letter to The Lancet that he has found a convincing correlation between fish consumption and the incidence of major depression. Dr. Hibbeln correlated the annual incidence of major depression per 100 people in nine countries with the consumption of fish. He found a high incidence of depression in countries with low fish consumption. New Zealand with an annual fish consumption of only 40 lbs had an annual incidence rate of depression of 5.8 per cent while Korea with a fish consumption of more than 100 lbs/year had an annual incidence rate of only 2.3 per cent. Japan with a fish consumption of almost 150 lbs/year had the lowest incidence of major depression (0.12 per cent). Dr. Hibbeln cautions that various economic, social, cultural and other factors could have influenced his results, but points out that high blood plasma concentrations of docosahexaenoic acid, an essential fatty acid found in fish, has been linked to increased serotonin turnover and lower incidences of depression and suicide.
Hibbeln, Joseph R. Fish consumption and major depression. The Lancet, Vol. 351, April 18, 1998, p. 1213 (correspondence)

Omega-3 fatty acid deficiency linked to depression
SHEFFIELD, UNITED KINGDOM. The composition of cell membranes has a profound effect on membrane-related proteins such as enzymes and receptors and there is considerable evidence that cell membrane structure is a significant factor in depression. This structure in turn is highly dependent on the presence of certain essential fatty acids, notably docosahexaenoic acid (DHA).

Researchers at the University of Sheffield and the Efamol Research Institute in Nova Scotia now report that they have found a highly significant association between severity of depression and the levels of omega-3 fatty acids in both the diet and the red blood cell membranes.

Their study involved 10 patients with major depression and 14 healthy control subjects with no history of psychiatric disorder (average age of participants was 39 years). All participants had blood samples taken and analyzed for essential fatty acid (EFA) content and also completed a questionnaire to determine their dietary intake of EFAs over the 7 days prior to enrollment.

The severity of depression was found to be inversely proportional with the red blood cell level and dietary intake of omega-3 fatty acids. The correlation between a low level of alpha-linolenic acid in blood cells and depression and between low blood cell levels of DHA and depression were particularly strong. No correlation was found between red blood cell levels of omega-6 fatty acids and depression. However, there was a slight positive correlation between dietary intake of omega-6s and severity of depression when both patients and controls were considered in one group. The researchers conclude that low levels of omega-3 fatty acids in cell membranes are associated with depression. They speculate that supplementation with omega-3 fatty acids may be useful in alleviating depression.
Edwards, Rhian, et al. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. Journal of Affective Disorders, Vol. 48, 1998, pp. 149-55

DHA levels linked to suicide and violence
BETHESDA, MARYLAND. Several studies have found a link between low cholesterol levels and an increased tendency to violence, suicide, and depression. Scientists at the National Institute on Alcohol Abuse and Alcoholism believe that the real culprit in this association is low concentrations of 5- hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid and that it is the blood level of polyunsaturated fatty acids rather than the levels of cholesterol which affect 5-HIAA levels. 5-HIAA is a metabolite of serotonin.

To test this hypothesis the researchers measured the levels of cerebrospinal 5-HIAA and the levels of blood plasma polyunsaturated fatty acids in a group of 176 subjects. Forty-nine of the subjects were healthy volunteers, 88 were early-onset alcoholics (excessive alcohol use prior to their 25th birthday), and 39 were late-onset alcoholics. None of the alcoholics had been drinking for at least 21 days prior to the test. The researchers found a strong positive correlation between blood levels of docosahexaenoic acid (DHA) and the level of 5-HIAA in the healthy volunteers. In other words, the higher the DHA levels the higher the 5-HIAA levels and as a corollary, the lower the tendency to depression, violence and suicide. In the early-onset alcoholics the situation was completely reversed. Higher DHA levels corresponded to lower 5-HIAA levels and thus a possibly increased tendency to violence, suicide and depression. The researchers found no correlation between 5-HIAA levels and total cholesterol levels. They conclude that further studies are required to determine if supplementation with essential fatty acids, notably DHA, can influence central nervous system serotonin and dopamine metabolism and modify impulsive behaviour related to these neurotransmitters.
Hibbeln, Joseph R., et al. Essential fatty acids predict metabolites of serotonin and dopamine in cerebrospinal fluid among healthy control subjects, and early- and late-onset alcoholics. Biological Psychiatry, Vol. 44, 1998, pp. 235-42

Your brain needs DHA
NEW YORK, NY. Dr. Barbara Levine, Professor of Nutrition in Medicine at Cornell University, sounds the alarm concerning a totally inadequate intake of DHA (docosahexaenoic acid) by most Americans. DHA is the building block of human brain tissue and is particularly abundant in the grey matter of the brain and the retina. Low levels of DHA have recently been associated with depression, memory loss, dementia, and visual problems. DHA is particularly important for fetuses and infants; the DHA content of the infant's brain triples during the first three months of life. Optimal levels of DHA are therefore crucial for pregnant and lactating mothers. Unfortunately, the average DHA content of breast milk in the United States is the lowest in the world, most likely because Americans eat comparatively little fish. Making matters worse is the fact that the United States is the only country in the world where infant formulas are not fortified with DHA. This despite a 1995 recommendation by the World Health Organization that all baby formulas should provide 40 mg of DHA per kilogram of infant body weight. Dr. Levine believes that postpartum depression, attention deficit hyperactivity disorder (ADHD), and low IQs are all linked to the dismally low DHA intake common in the United States. Dr. Levine also points out that low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. DHA is abundant in marine phytoplankton and cold-water fish and nutritionists now recommend that people consume two to three servings of fish every week to maintain DHA levels. If this is not possible, Dr. Levine suggests supplementing with 100 mg/day of DHA.
Levine, Barbara S. Most frequently asked questions about DHA. Nutrition Today, Vol. 32, November/December 1997, pp. 248-49

Fish consumption slows mental decline
ROTTERDAM, THE NETHERLANDS. Dutch researchers report an intriguing association between diet and the extent and rate of cognitive impairment in older men. Their study, part of the Zutphen Elderly Study, involved almost 1000 men born between 1900 and 1920. The men's intake of various food components was assessed (by personal interviews) in 1985 and 1990 and their cognitive function was evaluated in 1990 and 1993 using the Mini-Mental State Examination scale. The MMSE scale includes questions on orientation to time and place, registration, attention and calculation, recall, language, and visual construction.

The researchers found that men with the highest intake of linoleic acid (mainly from margarine, butter, baking fats, sauces, and cheeses) had a 76% higher degree of cognitive impairment than did men with the lowest intake. This association held true even after adjusting for age, level of education, cigarette smoking, alcohol consumption, and calorie intake. The intake of omega-3 fatty acids, on the other hand, was not associated with any degree of impairment. Men with a high fish intake were less likely to be cognitively impaired than men with a low intake and their rate of decline over the period 1990-93 was half that of men rarely consuming fish. The intake of beta-carotene, flavonoids, and vitamins C and E was not associated with a greater or lesser degree of impairment. However, there was a clear correlation between a high vitamin C intake and a decline in cognitive function over the period 1990-93. Men with a high vitamin C intake were twice as likely to have experienced a decline as were men with a low intake. The researchers speculate that vitamin C may act as a pro-oxidant in the presence of free iron in the brain.
Kalmijn, S., et al. Polyunsaturated fatty acids, antioxidants, and cognitive function in very old men. American Journal of Epidemiology, Vol. 145, January 1, 1997, pp. 33-41

Fatty acid profile linked to depression
MELBOURNE, AUSTRALIA. Depression is becoming increasingly prevalent in Western society. Some researchers believe that part of the reason for this can be traced to major dietary changes which have taken place over the past century. During this time there has been a large increase in the intake of saturated fats and linoleic acid (LA)-rich vegetable oils at the expense of alpha-linolenic acid (ALA)-rich foods such as fish and wild game. It is estimated that the ratio between LA-type (n-6) polyunsaturated fatty acids (PUFAs) and ALA-type (n-3) PUFAs has risen from 1:1 to 10:1 or higher. Some researchers have postulated that the sharp rises in depression and other neurological disorders are closely related to the increased intake of LA-rich vegetable oils.

Now researchers at the Royal Melbourne Institute of Technology report that the severity of depression is indeed directly associated with the ratio of LA- to ALA-type PUFAs in red blood cells. Their study involved 20 moderately to severely depressed patients. The severity of depression was determined using the 21-item Hamilton depression rating scale and a second scale which omitted anxiety symptoms. All patients had blood samples drawn and analyzed for arachidonic acid (AA) - the major metabolite of linoleic acid, and EPA - the major metabolite of alpha-linolenic acid and the main constituent of fish oils. The researchers found a clear correlation between a high AA/EPA ratio and increased severity of depression. There was also a significant association between a low level of EPA in the red blood cells and increased severity of depression.

The researchers conclude that there is a definite relationship between high AA/EPA ratios and increased severity of depression, but are not certain whether the fatty acid imbalance causes depression or whether depression results in a high AA/EPA ratio. They suggest that further studies be done to determine the benefits of supplementation aimed at increasing tissue levels of EPA and thereby decreasing the AA/EPA ratio.
Adams, Peter B., et al. Arachidonic acid to eicosapentaenoic acid ratio in blood correlates positively with clinical symptoms of depression. Lipids, Vol. 31 (suppl), 1996, pp. S157-S61

Fish oils alleviate schizophrenia symptoms
SHEFFIELD, UNITED KINGDOM. Schizophrenia is a serious mental illness characterized by such symptoms as delusions, hallucinations, emotional blunting, and social withdrawal. There is growing evidence that abnormalities in cell membrane fatty acid composition is involved in the disease. Researchers at the Northern General Hospital have just completed a study of the composition of red blood cell membranes in 23 drug-treated schizophrenic patients. They found that the patients had low levels of arachidonic acid (AA), linoleic acid (LA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) when compared to healthy controls. They also noted that the schizophrenics had higher levels of thiobarbituric acid reactive substances (TBARS) in their blood plasma indicating that the depletion of the fatty acids in the red blood cells might be due to an increase in oxidative breakdown reactions rather than to impaired incorporation of the fatty acids into the membranes.

A more recent study by the same researchers evaluated the effect of fish oil supplementation on the severity of schizophrenic symptoms in a group of 24 patients. They were given 10 grams/day of concentrated fish oil for a six-week period. The supplementation resulted in a marked increase in EPA and other omega-3 fatty acids in the red blood cell membranes and a concomitant decrease in omega-6 fatty acid levels. The researchers also noted a significant decrease in the severity of symptoms during the supplementation period. Interestingly enough, none of the patients were clinically deficient in fatty acid intake prior to supplementation, but a correlation between higher EPA intake and less severe symptoms was clearly evident. The researchers conclude that schizophrenia is somehow related to an abnormal fatty acid metabolism and urge larger clinical trials to evaluate the potential benefits of omega-3 fatty acid supplementation in the treatment of this disorder.
Laugharne, J.D.E., et al. Fatty acids and schizophrenia. Lipids, Vol. 31 (suppl), 1996, pp. S163-S65

Docosahexaenoic acid fights depression
ROCKVILLE, MARYLAND. Researchers at the National Institute of Alcohol Abuse and Alcoholism believe that the increasing rates of depression seen in North America over the last 100 years are due to a significant shift in the ratio of n-6 (arachidonic acid, linoleic acid) to n-3 (docosahexaenoic acid, linolenic acid) fatty acids in the diet. The human race evolved on a diet having a ratio of about 1:1 of these acids; it is now estimated to be between 10:1 and 25:1. Docosahexaenoic acid (DHA) is a main component of the synaptic membranes and a lack of it has been linked to depression. Fish oils are a rich source of DHA and it can also be biosynthesized in the body from linolenic acid. The researchers speculate that the depressions which often accompany alcoholism, multiple sclerosis, and childbirth (postpartum depression) are all due to a lack of DHA and can be corrected by increasing the dietary intake of DHA or linolenic acid (flax seed oil). They also point out that depression and coronary heart disease are strongly associated and that a low intake of n-3 fatty acids has been linked to both.
Hibbeln, Joseph R. and Salem, Norman. Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. American Journal of Clinical Nutrition, Vol. 62, July 1995, pp. 1-9

Fish oils help patient with Alzheimer's disease
MURRAYVILLE, VICTORIA, AUSTRALIA. Dr. Robert Peers, an Australian family physician, reports on the case of a 77-year-old farmer diagnosed with Alzheimer's disease (confirmed by a neurologist). The patient, when first admitted to a nursing home, was restless and destructive and unable to dress himself. After several months he became calmer, regained weight, and was again able to dress himself. Dr. Peers ascribes the changes to the fact that the nursing home served fish every week thus providing the patient with long-chain omega-3 fatty acids which had been missing in his previous diet. In the five years prior to being diagnosed with Alzheimer's disease (AD) the farmer had been in the habit of just frying up meat, rice and vegetables in an omega-6 vegetable oil. Dr. Peers provides a compelling scientific explanation of the reasons why a deficiency in docosahexaenoic acid (DHA), a main component of fish oil, may lead to Alzheimer's disease. He suggests that patients with AD should be queried about an excessive intake of omega-6 fatty acids (from vegetable oils and margarine) and a deficient intake of omega-3 fatty acids. If an imbalance is observed it should be treated with fish oil supplementation. He points out that DHA is quickly taken up by the brain and hypothesizes that fish oil supplementation may not only improve Alzheimer's symptoms, but may even prevent the disease from progressing further.

Two other Australian physicians, Drs. Simons and Broe, find Dr. Peers' observation interesting, but caution that considerably more research needs to be done for fish oil supplementation to be recognized as an effective treatment for AD.
Peers, Robert J. Alzheimer's disease and omega-3 fatty acids: hypothesis. Medical Journal of Australia, Vol. 153, November 5, 1990, pp. 563-64 (letter)

Low fat diet increases EPA and DHA levels
MINNESOTA, MINNEAPOLIS. Blood levels of fatty acids are believed to reflect the dietary intake of fatty acids. Researchers at the University of Minnesota now report that while high fat diets tend to increase the level of omega-6 fatty acids (generally undesirable) low fat diets tend to increase the level of beneficial omega-3 acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

Their clinical trial involved 10 healthy subjects who were randomized to receive a high fat diet (45% fat) for a 28-day period or a low fat diet (20% fat) for the same period. After a 3-4 week washout period the participants were fed the other diet for an additional 28 days. Blood samples were taken at the beginning and end of each feeding period. The two diets provided the same amount of calories (isoenergic) and had equivalent proportions of the different fatty acids notably linoleic and linolenic acids. The researchers noted that the high fat diet produced a significant increase in the proportion of omega-6 fatty acids, particularly the long chain ones, in the phospholipids and cholesterol fractions of the blood. In contrast, the low fat diet produced a significant increase in the proportion of omega-3 fatty acids, particularly EPA and DHA, in the phospholipids and cholesterol fractions and also resulted in a lower overall omega-6 content in these fractions.

The researchers speculate that the benefits of a low fat diet may, in part, be due to the higher blood levels (phospholipids and cholesterol fractions) of beneficial omega-3 fatty acids (especially EPA and DHA) engendered by a low fat diet.
Raatz, Susan K., et al. Total fat intake modifies plasma fatty acid composition in humans. Journal of Nutrition, Vol. 131, February 2001, pp. 231-34

Alpha-linolenic acid and DHA
GRONINGEN, THE NETHERLANDS. Alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA) have both been shown to reduce the risk of heart disease. Studies using isotopically labeled ALA have shown that it can be converted by the body to EPA (eicosapentaenoic acid) and DHA, but how significant this conversion is in actual practice is not known.

Dutch researchers now report that the conversion of ALA to DHA in vegans (strict vegetarians) is negligible and that supplementation with ALA does not increase DHA levels significantly. Their trial included 6 healthy men and 3 healthy women between the ages of 20 and 60 years who were adhering to a vegan diet (no meat, fish, eggs or dairy products). The participants were randomized to receive either 2.01 grams of ALA (4 ml linseed [flax] oil) daily or 1.17 grams of gamma-linolenic acid (6 ml borage oil) daily for a four-week period. This was followed by a four-week period during which all the participants received both supplements. Blood samples were taken and analyzed for fatty acid content at the start of the trial and after four and eight weeks. Neither the linseed oil nor the borage oil by themselves increased blood levels of EPA or DHA, but their combination did produce a statistically significant, but nevertheless negligible, increase in EPA and DHA in the cholesterol and triglyceride fractions of the blood. The researchers point out that a clinical trial involving omnivores (meat and fish eaters) gave similar results and conclude that ALA supplementation is not effective in increasing DHA levels significantly.
Fokkema, M.R., et al. Short-term supplementation of low-dose gamma-linolenic acid (GLA), alpha- linolenic acid (ALA), or GLA plus ALA does not augment LCP omega-3 status of Dutch vegans to an appreciable extent. Prostaglandins, Leukotrienes and Essential Fatty Acids, Vol. 63, November 2000, pp. 287-92

Dieting and depression
TUCSON, ARIZONA. Low-fat diets have been widely promoted for lowering cholesterol levels, for reducing body weight, and for preventing certain types of cancer. At least one study, however, has found that although a reduction in cholesterol may reduce mortality from heart disease it may increase the incidence of fatal accidents, violent deaths, suicides, and depression. Researchers at the University of Arizona now believe that they may have found an explanation for this phenomenon. They point out that fat restriction and cholesterol-lowering drugs may change the concentrations of polyunsaturated fatty acids (PUFAs) in the tissues including nerve tissue (neurons). Fat-restricting diets usually lead to a relative increase in the intake of omega-6 PUFAs and a relative decrease in the intake of omega-3 fatty acids. This can have serious consequences inasmuch as the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oils, are crucial for the proper functioning of the nervous system. Several large-scale studies have found a clear association between low blood levels of EPA and DHA and an increased risk of depression, violence and suicide; a recent study in Japan found that DHA supplementation reduced aggression among healthy Japanese students.

Fish consumption combats hypertension and obesity

Fish oil and margarine don't go together
ADELAIDE, AUSTRALIA. Fish oil supplements containing EPA (eicosapentaenoic acid) have an anti- inflammatory effect and may benefit people suffering from rheumatoid arthritis and psoriasis. This beneficial effect is significantly reduced when the diet is high in linoleic acid. A seven week controlled experiment involving 30 male volunteers was recently completed in Australia. The participants were given 1.6 gram EPA and 0.32 gram DHA (docosahexaenoic acid) daily. Half the volunteers were kept on a diet high in linoleic acid by using margarine as a spread and polyunsaturated oils for cooking. The other half used butter and olive oil which are low in linoleic acid. The experiment clearly showed that the incorporation of fish oil is enhanced by a diet containing butter and fish oil. Margarine and polyunsaturated oils had an inhibiting effect and should therefore be excluded from the diet in order to obtain maximum benefit from fish oil.
Cleland, Leslie G., et al. Linoleate inhibits EPA incorporation from dietary fish-oil supplements in human subjects. American Journal of Clinical Nutrition, Vol. 55, February 1992, pp. 395-99

Fish oils do not promote harmful peroxidation
CORVALLIS, OREGON. There is ample evidence that fish consumption and fish oil supplementation help protect against heart disease. However, the main components of fish oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are highly unsaturated and would therefore be prone to oxidation. This has prompted some researchers to express concern that fish oils might contribute to the lipid peroxidation involved in the development of atherosclerosis.

Researchers at the Oregon State University have just released two major studies designed to further explore this concern. The first study involved 15 postmenopausal women who were randomized to supplement with 15 grams/day of sunflower oil, 15 grams/day of safflower oil or 15 grams/day of fish oil (providing 2.0 grams of EPA and 1.4 grams of DHA per day) in a 3-treatment crossover trial. The researchers conclude that there is no evidence that fish oil supplementation increases lipid peroxidation when assessed by measuring the levels of blood plasma malondialdehyde (MDA) and F2-isoprostanes. However, a slight increase in thiobarbituric acid reactive substances (TBARS) was noted in the fish oil supplemented group. The researchers believe this to be insignificant and point out that the TBARS test is somewhat unreliable.

The second study involved 46 postmenopausal women who were randomly assigned to receive a daily fish oil supplement (providing 2.5 grams of EPA and 1.8 grams of DHA) combined with 0, 100, 200 or 400 mg of synthetic vitamin E (RRR-alpha-tocopherol acetate). Each of the 5-week treatment periods was followed by a 4-week washout interval in a 4-treatment, 4-period crossover design.

The researchers noted substantial increases in blood plasma levels of EPA (from 0.110 to 0.734 mmol/L) and DHA (from 0.283 to 0.515 mmol/L). They also observed an average drop in triglyceride concentrations of almost 30%. Vitamin E (alpha-tocopherol) levels rose by about 50% after supplementation with 100 mg/day (50 IU) of alpha-tocopherol-acetate and by about 69% after supplementation with 400 mg/day (200 IU). The increase in alpha-tocopherol level was accompanied by a significant decrease in gamma-tocopherol level. The researchers evaluated the effect of supplementation on lipid oxidation (TBARS) and protein oxidation (carbonyl groups). They did not observe any increased protein oxidation, but did find a small but statistically significant increase in TBARS concentration after fish oil supplementation; they dismiss this finding as being likely to be clinically irrelevant. The size of the increase did not change with increased vitamin E intake. The researchers conclude, "If fish oil consumption does not cause an increase in oxidation as measured by protein carbonyls, then an increased intake of vitamin E [during fish oil supplementation] is not necessary."
Higdon, Jane V., et al. Supplementation of postmenopausal women with fish oil rich in eicosapentaenoic acid and docosahexaenoic acid is not associated with greater in vivo lipid peroxidation compared with oils rich in oleate and linoleate as assessed by plasma malondialdehyde and F2-isoprostanes. American Journal of Clinical Nutrition, Vol. 72, September 2000, pp. 714-22
Wander, Rosemary C. and Du, Shi-Hua. Oxidation of plasma proteins is not increased after supplementation with eicosapentaenoic and docosahexaenoic acids. American Journal of Clinical Nutrition, Vol. 72, September 2000, pp. 731-37

Dr. Jan Eritsland, a cardiologist at the Ulleval University Hospital, has just released a major study dealing with the safety of n-3 and n-6 PUFAs. Based on numerous reports published in the medical literature Dr. Eritsland concludes that a high intake of n-3 PUFAs reduces the risk for cardiovascular disease and heart attack and is entirely safe at least up to a level corresponding to 10% of the daily calorie intake. He does caution though that the intake of dietary antioxidants (especially vitamin E) needs to be increased if the PUFA intake is increased. Supplementation with 4 grams/day of highly concentrated fish oil (containing 3.4 g of EPA and DHA) was found to lower triglyceride levels, but had no effect on cholesterol levels or glycemic control (plasma glucose and insulin levels). Although fish oils are known to reduce the tendency of blood to aggregate (clot) a recent major trial showed no difference in bleeding episodes among heart disease patients supplementing with 2 to 5 grams/day of fish oils and the controls. This held true even if the patients were also taking warfarin or aspirin. PUFAs of the n-3 family may help prevent cancer and there is no evidence at all that they promote it. There is, however, some limited evidence that n-6 PUFAs (linoleic acid) may indeed be involved in the initiation or promotion of cancer. Most experts recommend that the intake of linoleic acid not exceed 10% of daily calorie intake. [73 references]
Eritsland, Jan. Safety considerations of polyunsaturated fatty acids. American Journal of Clinical Nutrition, Vol. 71 (suppl), January 2000, pp. 197S-201S

Fish oil and vitamin E go together
BELTSVILLE, MARYLAND. Fish oils are beneficial in the prevention of cancer and cardiovascular disease. They do, however, oxidize very easily and therefore add to the oxidant stress on the body. An experiment was recently carried out by the U.S. Department of Agriculture to see if an increased intake of vitamin E could counteract this detrimental effect of fish oils. Forty men aged 32 to 44 were involved. The men consumed a controlled diet for a total of 28 weeks. For the first 10 weeks they received placebo oil capsules (15 g/day), for the next 10 weeks they received fish oil capsules (15 g/day), and for the last 8 weeks they received the fish oil plus 200 mg of vitamin E (all-rac-alpha-tocopherol). The urinary excretion of peroxidation products (malondialdehyde) more than doubled when the fish oil capsules were introduced but then dropped by a factor of four when vitamin E was added. The vitamin E concentration in the red blood cells dropped very significantly when fish oil was ingested but more than recovered with the vitamin E supplement. It is concluded that the negative effects of fish oil consumption can be overcome by taking them together with vitamin E.
Nair, Padmanabhan P., et al. Dietary fish oil-induced changes in the distribution of alpha-tocopherol, retinol, and beta-carotene in plasma, red blood cells, and platelets: modulation by vitamin E. American Journal of Clinical Nutrition, Vol. 58, July 1993, pp. 98-102

Fish oil supplements increase requirements for Vitamin E
LONDON, ENGLAND. A recent experiment carried out at King's College in London showed that daily intake of fish oil supplement reduces the plasma concentration of vitamin E to below normal range. Nine healthy male subjects were given a daily fish oil supplement containing 2.1 g docosahexaenoic acid (DHA) and 0.8 g eicosapentaenoic acid (EPA) for a six week period. The proportion of DHA and EPA in the blood increased during the trial while the concentration of very-low-density-lipoprotein-cholesterol and triacylglycerol decreased. Blood pressure fell slightly during treatment, but rose again once the fish oil supplementation was discontinued. Of particular interest was the finding that alpha-tocopherol (vitamin E) concentration in the blood fell from 20 micromol/l to about 10 micromol/l during the experiment. This raises the question whether fish oil supplementation increases the need for antioxidant supplementation.
Sanders, T.A.B. and Hinds, Allison. The influence of a fish oil high in docosahexaenoic acid on plasma lipoprotein and vitamin E concentrations and haemostatic function in healthy male volunteers. British Journal of Nutrition, Vol. 68, July 1992, pp. 163-73

Fish oils recommended for diabetes and hypertension
TROMSO, NORWAY. Fish and fish oils help protect against the development of atherosclerosis and heart disease. It is believed that fish oils exert their protective effect by lowering blood pressure and the levels of triglycerides and very-low-density lipoprotein (VLDL). Fish oils are also believed to reduce platelet aggregation and to suppress the growth of smooth-muscle cells in the arterial walls. Many people with hypertension also suffer from diabetes and there has been concern that fish oil supplementation may aggravate problems with glucose intolerance. Researchers at the University of Tromso now report that fish oil supplementation lowers blood pressure significantly in people with hypertension and has no effect on glucose control even in people with mild diabetes. The study involved 78 obese volunteers with essential hypertension. The participants were randomly assigned to one of two equal-sized groups. The fish oil group received four fish oil capsules a day (containing a total of 3.4 grams of a mixture of eicosapentaenoic acid and docosahexaenoic acid) for a period of 16 weeks. The control group received four corn oil capsules a day.

The researchers believe that consumption of fish increases the level of EPA and DHA in the membranes of the red blood cells which in turn reduces platelet aggregation and coronary spasm. This belief was confirmed by finding that blood samples taken from 95 cardiac arrest patients and 133 controls showed that a high blood content of EPA and DHA (five per cent of total fatty acids) corresponded to a 70 per cent reduction in the risk of cardiac arrest when compared to study participants with a low EPA and DHA content in their blood (3.3 per cent of total fatty acids). Other studies have shown that patients who have already suffered a heart attack can reduce their risk of future life-threatening arrhythmias and sudden cardiac death by increasing their intake of fish, fish oils or linolenic acid (flax seed oil). The researchers conclude that a modest intake of EPA and DHA from seafood may reduce the risk of ventricular fibrillation and death from coronary heart disease. NOTE: Fresh salmon is one of the best sources of fish oils; it contains twice as much per serving as does albacore tuna and six times more EPA and DHA than a serving of cod.
Siscovick, David S., et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Journal of the American Medical Association, Vol. 274, No. 17, November 1, 1995, pp. 1363-67

Fish oil supplementation does not increase bleeding tendency
OSLO, NORWAY. A group of Norwegian medical researchers reports that fish oil supplementation does not increase the bleeding tendency in heart disease patients receiving aspirin or warfarin. The study involved 511 patients who had undergone coronary artery bypass surgery. On the second day after the operation half the patients were assigned in a random fashion to receive 4 grams of fish oil per day (providing 2 g/day of eicosapentaenoic acid, 1.3 g/day of docosahexaenoic acid, and 14.8 mg/day of vitamin E). At the same time the patients were also randomized to receive either 300 mg of aspirin per day or warfarin aimed at achieving an INR of 2.5-4.2. The patients were evaluated every 3 months and questioned about bleeding episodes for the duration of the 9-month study.

The researchers concluded that fish oil supplementation did not result in a statistically significant increase in bleeding episodes in either the aspirin group or in the warfarin group. They also found no significant long-term effects of fish oil on common parameters of coagulation and fibrinolysis. They noted that the blood levels (serum phospholipid levels) of eicosapentaenoic acid and docosahexaenoic acid increased by 140% and 14% respectively in the patients taking fish oil. The serum triglyceride levels decreased by 19.1% in the fish oil group while no significant change was observed in the remainder of the patients. NOTE: This study was partially funded by Pronova Biocare AS (a fish oil manufacturer) and Nycomed Pharma AS.
Eritsland, J., et al. Long-term effects of n-3 polyunsaturated fatty acids on haemostatic variables and bleeding episodes in patients with coronary artery disease. Blood Coagulation and Fibrinolysis, Vol. 6, 1995, pp. 17-22

Consuming freshwater fish may lower risk of heart disease
KUOPIO, FINLAND. A 15-week experiment involving 62 students was carried out to determine if a regular diet of freshwater fish affects coronary heart disease risk factors. The students were divided into three groups: a fish eating group who made no other changes to their diet, a fish eating group who also decreased their overall fat intake and a control group (19 students) who ate a typical western diet. The special diet consisted of one fish meal a day (in addition to the regular diet) and provided about 0.25 g/day of eicosapentaenoic acid and 0.55 g/day of docosahexaenoic acid. Serum cholesterol was found to decrease in fish eaters who also decreased their lipid intake but not in the other groups. Blood triglyceride levels decreased significantly in the fish eating groups, but not in the control group. Levels of apolipoproteins A1 and B were lowered in both fish eating groups as was the formation of thromboxane B2 during incubation of whole blood. In the fish eating groups, the proportion of omega-3 fatty acids increased significantly in erythrocyte ghosts and platelets at the expense of omega-6 fatty acids. The results of the study support the contention that moderate fish consumption has a protective effect against coronary heart disease.
Agren, J.J., et al. Boreal freshwater fish diet modifies the plasma lipids and prostanoids and membrane fatty acids in man. LIPIDS, Vol. 23, No.10, October 1988, pp. 924-929

Fish oils help prevent macular degeneration

BOSTON, MASSACHUSETTS. Age-related macular degeneration (AMD) is a leading cause of blindness for which treatment options are limited. Note: The macula is responsible for detailed, fine central vision and is located at the center of the retina. Researchers at the Harvard Medical School have just released a major study that points to a close association between the development of AMD and the consumption of certain fats. The study involved 42,743 female nurses enrolled in 1984 and 29,746 male health professionals enrolled in 1986. The nurses completed 130-item food frequency questionnaires in 1984, 1986 and 1990 and the men completed them in 1986 and 1990.

By 1996 a total of 567 study participants (351 women and 216 men) had developed AMD with visual loss of 20/30 or worse. The researchers found that women with a high fat intake (fifth quintile) had a 63 per cent greater risk of AMD than women with a low intake (first quintile). For men, the increased risk was 36 per cent. The major contributors to the increased risk were high intake of linolenic acid and trans-fatty acids. In contrast, a high intake of docosahexaenoic acid (DHA), a main component of fish oils, was found to lower the risk of AMD by about 30 per cent. More than one serving per week of beef, pork or lamb as a main dish was associated with a 35 per cent increased risk of AMD when compared to an intake of less than three servings per month. Fish, especially canned tuna, was found to have a protective effect, with the participants who ate fish more than four times per week having a 35 per cent lower risk of AMD than people eating fish three times per month or less.

The researchers conclude that a high intake of linolenic acid may increase the risk of AMD. They caution though that their finding contradicts other studies that have shown that linolenic acid is protective against coronary heart disease.
Cho, Eunyoung, et al. Prospective study of dietary fat and the risk of age-related macular degeneration. American Journal of Clinical Nutrition, Vol. 73, February 2001, pp. 209-18

Fish consumption protects against macular degeneration
SYDNEY, AUSTRALIA. Age-related macular degeneration (maculopathy) is a leading cause of blindness in both Australia and the United States. There is some evidence that atherosclerosis and macular degeneration may both be related to a high intake of saturated fat and cholesterol. A large Australian study (Blue Mountain Eye Study) now confirms this connection. The study involved 3654 men aged 49 years or older who completed a 145-item, semi-quantitative food frequency questionnaire and also underwent a detailed eye examination including stereoscopic macular photography. Among the participants there were 240 cases (6.5%) of early-stage degeneration and 72 cases (2%) of late-stage disease. The study results confirmed that the incidence of late-stage macular degeneration was almost 3 times higher among the men with a daily cholesterol intake of 400 mg or more than among the men with an intake of 231 mg/day or less. Somewhat surprisingly there was also a strong correlation between the intake of monounsaturated fat (olive oil) and the incidence of early-stage macular degeneration. The men with an intake of 34 grams/day or more had a 48% greater incidence than the men with an intake of 25 grams/day or less. Regular fish consumption was found to be highly protective. The men who ate fish more than once a week had a 50% lower incidence of late-stage macular degeneration than did the men who ate fish less than once per month.
Smith, Wayne, et al. Dietary fat and fish intake and age-related maculopathy. Archives of Ophthalmology, Vol. 118, March 2000, pp. 401-04

Fish oils (EPA) speed up healing of ligament injuries

WEST LAFAYETTE, INDIANA. Ligaments are tough bands of fibrous connective tissue (mainly collagen) that link two bones together at a joint. Injuries to ligaments are notoriously slow to heal. Researchers at Purdue University now report the results of an intriguing experiment which shows that eicosapentaenoic acid (the main component of fish tissue oils) materially speeds up the healing of "wounded" ligament cells in vitro. The experiment was carried out on three cultures of animal medial collateral ligament cells. The first culture was treated with arachidonic acid (an n-6 polyunsaturated fatty acid), the second with eicosapentaenoic acid (an n-3 polyunsaturated fatty acid), and the third served as a control.

After four days the cells were analyzed to determine their fatty acid profile. The AA (arachidonic acid) treated cells were found to have an n-6 to n-3 ratio of 24.3 while the EPA (eicosapentaenoic acid) treated cells had a ratio of 1.1. This indicates that the two fatty acids were well-absorbed and incorporated into the cells. Next a "wound" was introduced into the surface layers of the cell cultures by streaking a sterile pipette across them. The rate at which ligament cells grew back into the "wound" was measured over a 72-hour period and taken as an indication of wound healing speed. Both the AA and EPA treated cultures showed a higher degree of regrowth in the wound area than did the control. However, while AA decreased the synthesis of collagen by the ligament cells, EPA markedly increased it.

The researchers conclude that dietary supplementation with fish oils (n-3 polyunsaturated fatty acids) could be used to improve the healing of ligament injuries by enhancing the entry of new cells into the wound area and by speeding up collagen synthesis.
Hankenson, Kurt D., et al. Omega-3 fatty acids enhance ligament fibroblast collagen formation in association with changes in interleukin-6 production. Proceedings of the Society for Experimental Biology and Medicine, Vol. 223, January 2000, pp. 88-95

Atopic diseases linked to fatty acid ratio

TURKU, FINLAND. An atopic disease is a form of allergy where the hypersensitivity reaction occurs at a location different from the initial contact point between the body and the offending agent (allergen). For example, food taken by mouth may cause an allergic skin reaction - atopic dermatitis. The incidence of atopic diseases such as dermatitis, allergic rhinitis, and asthma is rising in industrialized countries and now affects about 20% of the population.

A team of researchers from the University of Turku and Tufts University in Boston now report that the increase in atopic diseases is closely tied in with an increase in the consumption of omega-6 fatty acids (linoleic acid) which have pushed the ratio of omega-6 to omega-3 (alpha-linolenic, eicosapentaenoic, and docosahexaenoic acids) fatty acids in the diet to an unfavorably high level (10:1 or higher). An increasing dietary intake of linoleic acid has been linked to a rise in atopic diseases in both Germany and Japan. A recent study of Finnish and Swedish school children found that children with a high ratio of eicosapentaenoic acid to linoleic acid had a lower prevalence of atopic diseases while children with allergies tended to have a lower level of docosahexaenoic acid in their blood.

The researchers point out that the metabolic products (eicosanoids) of omega-6 fatty acids promote inflammation while the metabolites of omega-3 acids dampens inflammation. They also point to several clinical trials which have shown that supplementation with fish oil or alpha-linolenic acid can reduce the symptoms of atopic dermatitis and asthma. They conclude that an increased intake of omega-3 fatty acids (fish oils and alpha-linolenic acid) may alleviate atopic diseases caused by an excessive intake of omega-6 fatty acids.
Kankaanpaa, Pasi, et al. Dietary fatty acids and allergy. Annals of Medicine, Vol. 31, 1999, pp. 282-87 [61 references]

Fish oils benefit kidney patients

ROCHESTER, MINNESOTA. IgA nephropathy is a common kidney disease that often follows a viral infection of the gastrointestinal or upper respiratory tract. There is no known cure for the disease and treatment with steroids, antibiotics, anticoagulants, antiplatelet drugs, and phenytoin has been ineffective. About 20 to 40% of all IgA nephropathy patients develop renal failure 5 to 25 years after diagnosis.

Researchers at the Mayo Clinic report that supplementation with fish oils, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is highly effective in slowing down the progression of the disease. Their clinical trial involved 106 patients who had been diagnosed with IgA nephropathy. Fifty-five of the patients were randomized to receive 12 fish oil capsules daily (providing 1.87 grams of EPA and 1.36 grams of DHA in total) while the remaining 51 patients received 12 olive oil (placebo) capsules daily.

The progression of the disease was judged by regularly measuring the level of creatinine in blood serum during the two years of the trial. A clear difference was observed. While the patients in the fish oil group had an average median increase in serum creatinine of only 0.03 mg/dL the patients in the placebo group experienced an increase of 0.14 mg/dL annually indicating that their disease was progressing significantly faster. After four years 40% of the patients in the placebo group had died or developed end-stage renal disease as compared to only 10% in the fish oil group. No adverse effects of fish oil supplementation were observed.

The Mayo Clinic researchers conclude that fish oil supplementation retards the progression of IgA nephropathy. NOTE: This study was partially funded by Merck, Sharp & Dohme, a manufacturer of pharmaceuticals, and Seven Seas Health Care, a producer of fish oils.
Donadio, James V., et al. A controlled trial of fish oil in IgA nephropathy. New England Journal of Medicine, Vol. 331, November 3, 1994, pp. 1194-99
van Ypersele de Strihou, Charles. Fish oil for IgA nephropathy? New England Journal of Medicine, Vol. 331, November 3, 1994, pp. 1227-29 (editorial)

Fish oil supplementation alleviates Raynaud's disease

ALBANY, NEW YORK. Raynaud's phenomenon is characterized by periods of disrupted blood flow to the fingers caused by exposure to cold or stress. The condition is relieved by warming the affected parts. It is estimated that about 4% of the US population suffer from the primary form of this phenomenon, the so-called Raynaud's disease. Secondary Raynaud's phenomenon occurs in association with connective tissue disease (progressive systemic sclerosis).

Researchers at the Albany Medical College now report that supplementation with fish oils significantly reduces the symptoms of Raynaud's disease (primary Raynaud's phenomenon), but has no beneficial effects in secondary Raynaud's phenomenon. Their double-blind, placebo-controlled clinical trial involved 32 patients, 20 with primary disease and 12 with Raynaud's phenomenon secondary to progressive systemic sclerosis. The patients were exposed to a series of experiments which involved immersing their left hand into increasingly colder water baths for a five-minute period and then measuring the blood flow and systolic pressure in the index finger. Half the patients were given 12 1-gram fish oil capsules daily containing a total of 3.96 grams of eicosapentaenoic acid (EPA) and 2.64 grams of docosahexaenoic acid (DHA) while the other half received 12 olive oil capsules per day for a 12-week period.

The fish oil supplementation was found to be highly effective in alleviating the symptoms of Raynaud's disease. At the 12-week checkup the systolic pressure measured after immersion in the 15o C water bath increased by 40 mm Hg in the fish oil group compared to a drop of 3 mm Hg in the placebo group. Five of 11 patients who developed symptoms before the start of the experiment could not be induced to develop symptoms at all when evaluated after 6 and 12 weeks of supplementation. The researchers conclude that fish oil supplementation is highly effective in alleviating symptoms of primary Raynaud's phenomenon, but has no effect in secondary Raynaud's phenomenon.
DiGiacomo, Ralph A., et al. Fish-oil dietary supplementation in patients with Raynaud's phenomenon: a double-blind, controlled, prospective study. American Journal of Medicine, Vol. 86, February 1989, pp. 158-64

There are good fats and there are bad fats. Artificially produced trans-fatty acids are bad in any amount and saturated fats from animal products should be kept to a minimum. The best fats or oils rather, since they are liquid at room temperature, are those that contain the essential fatty acids so named because without them we die. Essential fatty acids are polyunsaturated and grouped into two families, the omega-6 EFAs and the omega-3 EFAs.

Seemingly minor differences in their molecular structure make the two EFA families act very differently in the body. While the metabolic products of omega-6 acids promote inflammation, blood clotting, and tumor growth, the omega-3 acids act entirely opposite. Although we do need both omega-3s and omega-6s it is becoming increasingly clear that an excess of omega-6 fatty acids can have dire consequences. Many scientists believe that a major reason for the high incidence of heart disease, hypertension, diabetes, obesity, premature aging, and some forms of cancer is the profound imbalance between our intake of omega-6 and omega-3 fatty acids. Our ancestors evolved on a diet with a ratio of omega-6 to omega-3 of about 1:1. A massive change in dietary habits over the last few centuries has changed this ratio to something closer to 20:1 and this spells trouble. [1-3]

Sources and requirements
The main sources of omega-6 fatty acids are vegetable oils such as corn oil and soy oil which contain a high proportion of linoleic acid. Omega-3 acids are found in flaxseed oil, walnut oil, and marine plankton and fatty fish. The main component of flaxseed and walnut oils is alpha-linolenic acid while the predominant fatty acids found in fatty fish and fish oils are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The most beneficial and active of these fatty acids are EPA and DHA. Alpha-linolenic acid can be converted to EPA and DHA in the body, but the conversion is quite inefficient especially in older people. [1, 2]

Scientists were first alerted to the many benefits of EPA and DHA in the early 1970s when Danish physicians observed that Greenland Eskimos had an exceptionally low incidence of heart disease and arthritis despite the fact that they consumed a high-fat diet. Intensive research soon discovered that two of the fats (oils) they consumed in large quantities, EPA and DHA, were actually highly beneficial. More recent research has established that fish oils (EPA and DHA) play a crucial role in the prevention of atherosclerosis, heart attack, depression, and cancer. Clinical trials have shown that fish oil supplementation is effective in the treatment of many disorders including rheumatoid arthritis, diabetes, ulcerative colitis, and Raynaud's disease. [1-5]

Recognizing the unique benefits of EPA and DHA and the serious consequences of a deficiency the US National Institutes of Health recently published Recommended Daily Intakes of fatty acids. They recommend a total daily intake of 650 mg of EPA and DHA, 2.22 g/day of alpha-linolenic acid and 4.44 g/day of linoleic acid. Saturated fat intake should not exceed 8 per cent of total calorie intake or about 18 g/day.

Good for the brain and children too
The human brain is one of the largest "consumers" of DHA. A normal adult human brain contains more than 20 grams of DHA. Low DHA levels have been linked to low brain serotonin levels which again are connected to an increased tendency to depression, suicide, and violence. A high intake of fish has been linked to a significant decrease in age-related memory loss and cognitive function impairment and a lower risk of developing Alzheimer's disease. A recent study found that Alzheimer's patients given an omega-3-rich supplement experienced a significant improvement in their quality of life.[6-9]

Several studies have established a clear association between low levels of omega-3 fatty acids and depression. Other studies have shown that countries with a high level of fish consumption have fewer cases of depression. Researchers at Harvard Medical School have successfully used fish oil supplementation to treat bipolar disorder (manic- depressive illness) and British researchers report encouraging results in the treatment of schizophrenia. [10-15]

An adequate intake of DHA and EPA is particularly important during pregnancy and lactation. During this time the mother must supply all the baby's needs for DHA and EPA because it is unable to synthesize these essential fatty acids itself. DHA makes up 15 to 20% of the cerebral cortex and 30 to 60% of the retina so it is absolutely necessary for normal development of the fetus and baby. There is some evidence that an insufficient intake of omega-3 fatty acids may increase the risk of premature birth and an abnormally low birth weight. There is also emerging evidence that low levels of omega-3 acids are associated with hyperactivity in children. [1, 3, 16-22]

The constant drain on a mother's DHA reserves can easily lead to a deficiency and some researchers believe that preeclampsia (pregnancy- related high blood pressure) and postpartum depression could be linked to a DHA deficiency. Experts recommend that women get at least 500- 600 mg of DHA every day during pregnancy and lactation. The easiest way to ensure this intake is to take a good fish oil supplement daily. [17-19]

Researchers at the University of Sydney have found that children who regularly eat fresh, oily fish have a four times lower risk of developing asthma than do children who rarely eat such fish. They speculate that EPA present in the fish may prevent the development of asthma or reduce its severity by reducing airway inflammation and responsiveness. Researchers at the University of Wyoming have found that supplementation with 3.3 grams/day of fish oil markedly reduces breathing difficulties and other symptoms in asthma patients. Other research has found fish oil to be beneficial in the treatment of other lung diseases such as cystic fibrosis and emphysema. [23-29]

The heart's best friend
An enormous amount of medical literature testifies to the fact that fish oils prevent and may help to ameliorate or reverse atherosclerosis, angina, heart attack, congestive heart failure, arrhythmias, stroke, and peripheral vascular disease. Fish oils help maintain the elasticity of artery walls, prevent blood clotting, reduce blood pressure and stabilize heart rhythm. [1-4, 30-33]

Danish researchers have concluded that fish oil supplementation may help prevent arrhythmias and sudden cardiac death in healthy men. An Italian study of 11,000 heart attack survivors found that patients supplementing with fish oils markedly reduced their risk of another heart attack, a stroke or death. A group of German researchers found that fish oil supplementation for 2 years caused regression of atherosclerotic deposits and American medical researchers report that men who consume fish once or more every week have a 50% lower risk of dying from a sudden cardiac event than do men who eat fish less than once a month. [34-40]

Greek researchers report that fish oil supplementation (10 grams/day) reduces the number of attacks by 41% in men suffering from angina. Norwegian medical doctors have found that fish oil supplementation reduces the severity of a heart attack and Indian researchers report that supplementation started immediately after a heart attack reduces future complications. Bypass surgery and angioplasty patients reportedly also benefit from fish oils and clinical trials have shown that fish oils are safe for heart disease patients. The evidence is indeed overwhelming. An adequate daily intake (about 1 gram) of EPA and DHA is essential to maintain a healthy heart. Fish oils are especially important for diabetics who have an increased risk of heart disease. [41-49]

Researchers at the University of Cincinnati have found that supplementing with as little as 2 grams/day of fish oil (410 mg of EPA plus 285 mg of DHA) can lower diastolic pressure by 4.4 mm Hg and systolic pressure by 6.5 mm Hg in people with elevated blood pressure. Enough to avoid taking drugs in cases of borderline hypertension. Several other clinical trials have confirmed that fish oils are indeed effective in lowering high blood pressure and that they may work even better if combined with a program of salt restriction. [50-55]

Reduces pain and helps prevent cancer
Fish oils are particularly effective in reducing inflammation and can be of great benefit to people suffering from rheumatoid arthritis or ulcerative colitis. Daily supplementation with as little as 2.7 grams of EPA and 1.8 grams of DHA can markedly reduce the number of tender joints and increase the time before fatigue sets in. Some studies have also noted a decrease in morning stiffness and at least two clinical trials concluded that arthritis patients who took fish oils could eliminate or sharply reduce their use of NSAIDs and other arthritis drugs. [56-61]

Patients with ulcerative colitis have abnormally low blood levels of EPA. Clinical trials have shown that supplementation with fish oil (2.7 grams of EPA and 1.8 grams of DHA daily) can reduce the severity of the condition by more than 50% and enable many patients to discontinue anti-inflammatory medication and steroids. [62-64]

There is now also considerable evidence that fish oil consumption can delay or reduce tumor development in breast cancer. Studies have also shown that a high blood level of omega-3 fatty acids combined with a low level of omega-6 acids reduces the risk of developing breast cancer. Daily supplementation with as little as 2.5 grams of fish oils has been found effective in preventing the progression from benign polyps to colon cancer and Korean researchers recently reported that prostate cancer patients have low blood levels of omega-3 fatty acids. Greek researchers report that fish oil supplementation improves survival and quality of life in terminally ill cancer patients. [65-73]

Safe and easily available
It is estimated that 85% or more of people in the Western world are deficient in omega-3 fatty acids and most get far too much of the omega-6 fatty acids. Vegetarian diets, for example, tend to be very high in omega-6.

The recommended daily intake of EPA plus DHA is about 650 mg rising to 1000 mg/day during pregnancy and lactation. Clinical trials have used anywhere from 1 g/day to 10 g/day, but little additional benefit has been observed at levels above 5 g/day of EPA and DHA combined. The benefits of therapeutic supplementation may become evident in a few weeks when blood parameters (triglycerides, fibrinogen) are involved, but may take 3 months or longer to materialize in degenerative diseases like atherosclerosis and rheumatoid arthritis. [74, 75]

The processing and packaging of the fish oil are crucial in determining its quality. Low quality oils may be quite unstable and contain significant amounts of mercury, pesticides, and undesirable oxidation products. High quality oils are stabilized with adequate amounts of vitamin E and are packaged in individual foil pouches or other packaging impervious to light and oxygen. Some very recent research carried out at the University of Minnesota found that emulsified fish oils are much better absorbed than the straight oils in gelatin capsules. [76]

Cod liver oils and fish oils are not the same. Cod liver oil is extracted from cod liver and is an excellent source of vitamins A and D. Fish oils are extracted from the tissues (flesh) of fatty fish like salmon and herring and are good sources of EPA and DHA. Fish oils contain very little vitamin A and D, but cod liver oil does contain EPA and DHA. However, you would probably exceed the recommended daily intake of vitamins A and D if you were to try to obtain therapeutic amounts of EPA and DHA from cod liver oil.

Supplementing with fish oils has been found to be entirely safe even for periods as long as 7 years and no significant adverse effects have been reported in hundreds of clinical trials using as much as 18 grams/day of fish oils. Fish oil supplementation does, however, lower blood concentrations of vitamin E so it is a good idea to take extra vitamin E when adding fish oils to your diet. A clinical trial carried out by the US Department of Agriculture found that taking 200 mg/day of synthetic vitamin E (equivalent to about 100 IU of natural alpha- tocopherol) is sufficient to completely counteract this effect of fish oil supplementation. [74, 75, 77, 78]

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DHA & EPA

The Omega-3 and Omega 6 fatty acids make up two families of fats that are absolutely essential to human life. These essential fatty acids are important because they form important components of our cell membranes. They also regulate the body’s use of cholesterol and the production of substances that regulate nearly all other bodily processes.*

Most of the vegetable oils we consume today have high amounts of Omega-6. But these oils have very little Omega-3. Today nutritional science is validating more and more healthful benefits that Omega-3 fatty acids can have on the human mind and body. Omega-3 fatty acids in their long-chain forms, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are both found almost exclusively in deep, cold water fish. EPA is needed to create health-promoting prostaglandins that support cardiovascular health and cell membranes throughout the body. DHA is vital for a healthy brain, eyes and reproductive system. *

The body works best when the two types of fatty acids are combined in the right proportions. Because there is evidence that people in industrialized nations have a disproportionately high intake of Omega-6 fatty acids, it is suggested that we reduce our intake of Omega-6 and increase our intake of Omega-3.

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