A new meta-analysis published in the Journal of Clinical Lipidology1 has concluded that EPA and DHA omega-3 fatty acid supplementation helps reduce the risk of coronary mortality, also known as “cardiac death.” The study, which was funded by the Global Organization for EPA and DHA Omega-3s (GOED; Salt Lake City, UT), is the “first published meta-analysis to include cardiac death…as a primary endpoint, and the most comprehensive review of the evidence to date,” the association says. The meta-analysis, comprising results from 14 randomized, controlled trials featuring 71,899 subjects, found that omega-3 supplementation (either via dietary supplements or pharmaceuticals) may reduce the risk of cardiac death by 8%. In addition, the meta-analysis indicated an even greater risk reduction of 17% in subjects with already elevated triglycerides or LDL cholesterol.
GOED notes that cardiac death currently accounts for roughly two-thirds, or 405,000, of all cardiovascular disease deaths in the United States annually. Globally, cardiac death accounts for 42% of cardiovascular disease deaths annually, or 7.4 million people.
All of the studies included in the meta-analysis were conducted over a period of at least six months and with the specific endpoint of investigating the effects of omega-3 supplementation on cardiac death. Researchers analyzed data from studies that were published through December 2016 that included both dietary supplement and pharmaceutical omega-3 interventions. (The meta-analysis did not include studies examining the effects of dietary EPA and DHA consumed from fish.)
Overall, the researchers found that supplemental EPA and DHA omega-3s reduced the risk of cardiac death by a statistically significant average of 8%. The study authors found that, in the omega-3 groups, there were 1,613 cardiac deaths recorded (4.48% of subjects), while in the control groups 1,746 cardiac deaths were recorded (4.87% of subjects).
Meanwhile, the researchers found greater risk reduction in subjects with high triglycerides and LDL cholesterol, findings that are in line with the theory that omega-3 supplementation may be most beneficial for reducing cardiac death in higher-risk individuals. This is a significant hypothesis because, as GOED notes, the National Center for Health Statistics estimates that 25% of adults in the United States have high triglyceride levels (≥150 mg/dL) and that 27% have LDL cholesterol levels greater than or equal to 130 mg/dL.
The researchers also found the greatest reduction in cardiac death rates—an almost 30% risk reduction—in those trials that utilized omega-3 dosages of more than 1 g of EPA and DHA per day.
These results counter suggestions that omega-3s don’t benefit cardiovascular disease risk reduction. Harry B. Rice, PhD, vice president of regulatory and scientific affairs, GOED, stated in a press release: “This study is important because it explored the effects of omega-3s on a specific outcome of coronary heart disease. A number of studies in recent years have questioned omega-3 benefits in cardiovascular diseases. In order to understand the role omega-3s play in the cardiovascular system, however, research has to focus on a specific disease rather than all cardiovascular outcomes together. This is an important nuance that this meta-analysis helps clarify.”
Kevin Maki, PhD, lead study author and chief scientist for Midwest Biomedical Research’s Center for Metabolic and Cardiovascular Health, added: “It’s important to note that these results align with the conclusions in the recent Science Advisory from the American Heart Association, which states that EPA and DHA omega-3 treatment ‘is reasonable’ for secondary prevention of coronary heart disease and sudden cardiac death. One notable feature of EPA and DHA omega-3 supplementation is the low risk associated with its use. Because of the low risk for adverse effects, even a modest benefit is clinically meaningful.”
- Maki KC et al., “Use of supplemental long-chain omega-3 fatty acids and risk for cardiac death: an updated meta-analysis and review of research gaps.” Journal of Clinical Lipidology. Published online August 2, 2017.