In an attempt to extract some clarity from the conflicting results of trials examining omega-3 fatty acids’ role in coronary heart disease (CHD) and major vascular events, researchers conducted a meta-analysis1 of existing trials, the results of which appeared recently online in the Journal of the American Medical Association (JAMA) Cardiology.
The meta-analysis considered 10 large randomized trials involving a total of 77,917 participants who supplemented with marine-derived omega-3 fatty acids for a mean of 4.4 years. The main outcomes the researchers tracked included fatal CHD, nonfatal myocardial infarction, stroke, and all-cause mortality, along with major vascular events in study population subgroups. The results showed that amongst the studies’ overall populations and their subgroups—including subgroups whose members had a history of CHD, diabetes, high lipid levels, or statin use—randomization to omega-3 fatty acid supplementation had no significant associations with CHD death, nonfatal myocardial infarction, any coronary heart disease events, or major vascular events. Thus, the authors concluded, the meta-analysis “provides no support for current recommendations for the use of such supplements in people with a history of coronary heart disease.”
Not surprisingly, members of the dietary supplement industry—in an attempt to impose some clarity of their own—were quick to respond to the meta-analysis’ conclusions. The Global Organization for EPA and DHA Omega-3s (GOED; Salt Lake City) is monitoring the media coverage of the findings and issued a statement to its members affirming several points, including that the meta-analysis adds little to the current body of evidence surrounding omega-3s and cardiovascular risk factors.
The organization noted that the study did not find an absence of risk reduction related to omega-3 supplementation; rather, the associations it found were simply not statistically significant and don’t support the current guidelines, according to the authors. (That said, the study’s authors refrained from advocating any subsequent change to the guidelines, GOED pointed out.) GOED also noted that four large trials will be published in 2018 and 2019, adding to the totality of omega-3 research, and to understanding of the compounds’ relationship to heart health.
For its part, the Council for Responsible Nutrition (CRN; Washington, DC) issued a response of its own through Duffy MacKay, ND, its senior vice president for scientific & regulatory affairs. Speaking in the statement, MacKay conceded that the meta-analysis didn’t produce the dramatic results of a drug intervention, but that it did “identify the potential for a 7% lower risk of major vascular events and a 10% lower risk of coronary heart disease associated with omega-3 fatty acid supplements. Even though these results are not statistically significant, they come close, thereby validating nutritional interventions, such as omega-3 fatty acids, as having subtle, but important, effects.”
Further, while the 2015–2020 Dietary Guidelines for Americans encourage us to consume eight or more ounces of seafood per week, partly to benefit from their omega-3 fatty acid content, many Americans aren’t. “When taking into consideration the high safety profile of omega-3 fatty acid supplements,” MacKay said, “they are a prudent choice to ensure that consumers obtain adequate levels of this nutrient needed for good health.”
- Aung T et al., “Associations of omega-3 fatty acid supplement use With cardiovascular disease risks meta-analysis of 10 trials Involving 77 917 individuals,” JAMA Cardiology. Published online ahead of print, January 31, 2018.