Omega-3s and Cardiovascular Events Study Questioned

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WholeFoods Magazine Staff
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Washington, D.C.—In an analysis of previous studies that included almost 70,000 people, researchers from Greece concluded that omega-3 fatty acid supplementation is not significantly correlated with reduced risk of all-cause death, cardiac death, sudden death, heart attack, or stroke. The study, published in the September 12 issue of JAMA, has provoked a response from the Council for Responsible Nutrition (CRN) and other groups, which urge consumers to remain confident in the benefits of omega-3s.

The researchers cite the widespread use of omega-3s around the world, and the research both supporting and not supporting their use as cardiovascular health aids as background. They also refer to the recommendation by some government guidelines of omega-3 use for various cardiovascular health indicators, like for lowering triglycerides in the United States. They analyzed 20 studies with 68,680 randomized patients, which together reported 7,044 deaths, 3,993 cardiac deaths, 1,150 sudden deaths, 1,837 heart attacks and 1,490 strokes. It was against these numbers that they found no statistical link between omega-3 use and cardiac risk.

“Our findings do not justify the use of omega-3 as a structured intervention in everyday clinical practice or guidelines supporting dietary omega-3 PUFA administration. Randomized evidence will continue to accumulate in the field, yet an individual patient data meta-analysis would be more appropriate to refine possible associations related to, among others, dose, adherence, baseline intake and cardiovascular disease risk group,” the study authors concluded.

Duffy MacKay, N.D., vice president of scientific and regulatory affairs for CRN responded in a statement, “This study does not change the current recommendations by authoritative bodies such as the World Health Organization, American Heart Association and the U.S. National Academies of Science, who recommend adequate consumption of omega-3 fats.”

He also notes several factors that may undermine the author’s conclusions. These include the lack of differentiation between studies on those in the midst of or at risk for cardiac disease, and those conducted on healthy individuals. The Global Organization for EPA and DHA (GOED) also released a statement, which claimed the study failed to account for the effect of cardiovascular disease medications on such research.

The length of individual studies and dosage levels should also be taken into consideration in a review such as this, says WholeFoods science editor Richard Passwater, Ph.D., research director of the Selenium Nutritional Research Center in Berlin, MD and co-author of The Missing Wellness Factors: EPA and DHA. “The data that should be considered in conducting a meta-analysis of the effect of fish oil and related long-chain omega-3 foods in diseased persons should be from studies lasting more than 2 years and involving dosages of EPA and DHA of more than 1,000 milligrams, and the Omega-3 Index of the placebo groups should be controlled for,” Passwater says.

There is also the fact that in supplement studies, the dietary intake levels of nutrients like omega-3s are not always accounted for in the placebo group, potentially skewing the results. Some may already be getting the long-term health benefits of omega-3s, MacKay argues. He said, “It is impossible for five researchers to control the diet of almost 70,000 patients over several years (particularly as a retrospective meta-analysis), as omega-3 fats are widespread throughout a variety of foods.”

Published in WholeFoods Magazine, October 2012 (online 9/12/12)