Essential Fatty Acids Lower Risk of Heart Disease
Dietary and supplemental intake of omega-3 fatty acids may reduce the risk of heart attack or sudden death, according to a study published in the American Journal of Medicine.1 The authors pooled the results of several studies (a meta-analysis) to better determine whether these compounds protect against heart disease.
The researchers searched several databases for all published controlled trials using omega-3 fatty acids, either as a supplement or as part of a dietary intervention. The studies had to meet three criteria: (1) trials had to compare dietary or supplemental intake of omega-3 fatty acids with a control diet or placebo, (2) studies had to report the incidence of heart attacks or death among people who participated, and (3) trial participants with heart disease had to have been followed for at least six months. Eleven studies met these criteria, with a combined total of roughly 8,000 individuals each in the treatment group and control groups.
The results of the meta-analysis showed that consumption of omega-3 fatty acids through diet or nutritional supplementation significantly reduced the risk of heart disease. The risk of nonfatal heart attack, fatal heart attack, sudden death, and death from all causes in those who consumed omega-3 fatty acids was reduced by 20%, 30%, 30%, and 20%, respectively, compared with the risk in those consuming a control diet or placebo. The results seen in dietary-intervention studies were slightly more pronounced than those observed in nutritional-supplementation studies. However, only 2 of the 11 studies evaluated dietary intervention as a means of increasing omega-3 fatty acid intake, and both of those studies were small and neither well designed. It may, therefore, be premature to conclude that dietary modification is more effective than supplementation with omega-3 fatty acids.
Omega-3 fatty acids contribute to heart-disease prevention by causing several chemical changes in the blood vessels (dilating blood vessels, suppressing inflammation, and controlling growth of the cells that line the inner part of the arteries). The combined effect keeps arteries wide open, so blood can flow without restriction.
Although the authors do not specify an optimal daily intake, trials that tested nutritional supplements of omega-3 fatty acids used 0.3 to 6 grams of eicosapentaenoic acid (EPA) and 0.6 to 3.7 grams of docosahexaenoic acid (DHA) per day. This is approximately equivalent to consuming 4 to 12 ounces of cold-water fish per day. Good dietary sources of omega-3 fatty acids include cod, salmon, mackerel, halibut, and flaxseed. The analysis suggests that regular intake of omega-3 fatty acids in the diet or in supplement form may lead to a healthier heart and a longer life.
1. Bucher HC, Hengstler P, Schindler C, Meier G. N-3 Polyunsaturated Fatty Acids in Coronary Heart Disease: A Meta-Analysis of Randomized Controlled Trials. Am J Med 2002;112:298–304.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of Garlic and Cholesterol: Everything You Need to Know (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice in Westport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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