Diets rich in fish and fish-oil supplements have long been claimed to prevent heart disease. The evidence to support this is the vast body of research studies and references that support the cardiovascular benefits of fish consumption and omega-3 supplementation. However, a recent large study (Alpha Omega Trial) examining the role of omega-3–enriched margarine as a functional food for secondary prevention of heart attacks revealed negative results. Using a meta-analysis, other investigators also showed insufficient evidence of a secondary preventive effect of omega-3 fatty acid supplements against overall cardiovascular events among patients with a history of cardiovascular disease. Publication of these studies has caused skepticism about the cardioprotective effects of omega-3 fats and has generated controversy over fish-oil and omega-3 supplements.
In 2002 in its scientific statement on fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease, The American Heart Association announced that “randomized controlled trials have demonstrated that omega-3 fatty acid supplements can reduce cardiac death, nonfatal MI, nonfatal stroke, and atherosclerosis in coronary patients. But, additional research is needed to confirm the health benefits of omega-3 fatty acid supplements for both primary and secondary prevention.”
The FDA has also approved Lovaza (omega-3-acid ethyl esters) as the only fish-oil supplement. While Lovaza is indicated for lowering elevated triglycerides, its labeling specifically states that “the effect of Lovaza on cardiovascular mortality and morbidity in patients with elevated triglyceride levels has not been determined.”
In late 2004, the FDA also announced, “Supportive but not conclusive research shows that consumption of eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA] omega-3 fatty acids may reduce the risk of coronary heart disease.”
A recent investigation showed that 60% of U.S. clinicians surveyed agreed that one of their roles as health care professionals is to provide information to patients about appropriate dietary supplements. The most popular supplements among cardiologists were multivitamins, omega-3/fish oil, and vitamin C. A majority of the U.S. population consumes fish-oil supplements daily, and this is due to the fact that a high percentage of health care providers recommend the daily use of these products to the public.
With the results of the above studies, the questions remain: Is fish oil cardioprotective or not? And what happens to the potential advocacy by health care professionals? In this article, we will review recent literature and recommendations on this major food supplement. Ultimately, consumers must educate themselves about the benefits of fish oil as well as consult with their doctors when deciding whether to take the supplements or not.
