Do Omega-3 Fats Support Heart Health?
Researchers found that omega-3 fat supplementation was not associated with a lower risk of all-cause mortality
A review of existing research and reanalysis of certain studies on omega-3 fats and heart health has resulted in a surprising finding: The review calls into question the long-standing positive association between heart health and fish oil supplementation. The focus of the analysis was omega-3 supplements rather than dietary sources.
Fishing for better health
In this study, heart and vascular health was measured by longevity: death due to any cause (all-cause mortality), cardiac death, or sudden death due to heart disease, heart attack, and stroke. Researchers pooled results from 20 previous studies of a total 68,680 adults in a statistical method called meta-analysis. All of the studies included in the meta-analysis were clinical trials in which some of the participants were given omega-3 fat supplements and others were given a placebo (containing no omega-3s).
Researchers found that omega-3 fat supplementation was not associated with a lower risk of all-cause mortality, cardiac death, sudden death, myocardial infarction, or stroke. For all of the conditions other than stroke, the results trended in the direction of fish oil supplements protecting against cardiovascular disease, though these results weren't statistically significant. For stroke, the result trended in the direction of suggesting more harm than benefit from omege-3 fat supplements, though again, results were not statistically significant.
Putting results in context
Why do omega-3s have a heart-healthy reputation? While the results of the meta-analysis demonstrate that the relationship between fish oil and heart health is more complicated than previously thought, keep in mind that, among other heart-related benefits, fish oil has been shown to reduce high blood pressure and high triglycerides, both considered markers for heart disease risk. And studies have consistently associated fish-rich diets, such as the Mediterranean-style diet, with better cardiovascular health.
It should also be considered that of the 3,635 studies assessed, just 20 made the cut for the meta-analysis. Studies are often eliminated because a study's design makes it difficult to compare with other studies, but they may still be relevant to the larger question of a supplement's efficacy. Of the more than 3,600 other studies on omega-3 fat that were not included in the review, many support health benefits of taking omega-3 fat supplements.
Cutting through the confusion
So what's a health-conscious consumer to do? Before deciding whether or not omega-3 supplements are right for you, ask yourself some of these questions:
(JAMA 2012;Vol 308:1024-33)
Suzanne Dixon, MPH, MS, RD, an author, speaker, and internationally recognized expert in chronic disease prevention, epidemiology, and nutrition, has taught medical, nursing, public health, and alternative medicine coursework. She has delivered over 150 invited lectures to health professionals and consumers and is the creator of a nutrition website acclaimed by the New York Times and Time magazine. Suzanne received her training in epidemiology and nutrition at the University of Michigan, School of Public Health at Ann Arbor.