Death from heart attack: Omega 3 EPA and DHA supplements reduce risk by 8%

The consumption of dietary supplements or pharmaceutical products containing omega 3 reduces the risk of cardiac death by 8%. This percentage rises to 17% in subjects with high cholesterol or triglycerides, and up to 30% in those who take more than one gram per day of EPA and DHA supplementation. These data suggest that omega-3 supplements could represent an effective and side-effect-free strategy for the prevention of heart disease and sudden cardiac death.

This was discovered by scientists from Midwest Biomedical Research and Johns Hopkins University (USA) through a study that analyzed the combined results of numerous studies, recently published in the Journal of Clinical Lipidology.

Cardiovascular risk and omega-3: a long-studied relationship

Cardiovascular diseases represent the leading cause of mortality and disability in Western countries. Their spread is due both to pathological conditions and the widespread adoption of unhealthy lifestyles. Cardiovascular diseases include all those affecting the heart and blood vessels. The most frequent are myocardial infarction, angina pectoris, cardiomyopathies, heart failure, arrhythmias, and stroke. Fifty percent of all deaths from cardiovascular diseases are due to sudden cardiac death, defined as death from cardiac causes with sudden loss of consciousness within one hour from symptom onset. Most population studies conducted in industrialized countries have shown that the risk factors for sudden cardiac death are the same as for coronary artery disease; these include advanced age, male sex, family history, increased LDL cholesterol levels, hypertension, smoking, and diabetes mellitus. The relationship between a diet rich in fish containing omega-3 fatty acids and protection from cardiovascular diseases has been confirmed by many studies over recent decades. The mechanisms by which omega-3 exert protective cardiovascular effects are varied: they increase the fluidity of cell membranes, improve endothelial function, modulate platelet aggregation, have antiarrhythmic properties, and help reduce blood triglycerides.

EPA and DHA reduce risk of cardiac death by 8%

During the meta-analysis, researchers collected data from over 70,000 people and compared the incidence of cardiac death events between subjects consuming omega-3 as supplements or drugs and control subjects who did not. The results showed that omega-3 can reduce the risk of cardiac death on average by 8%. This percentage was even higher (17%) in subjects with high triglycerides or LDL cholesterol. 

EPA and DHA consumption was associated with an even greater reduction in the risk of cardiac death by 30% in people who consumed doses exceeding 1 gram of omega-3 per day. "It is important to note that these results align with the recent scientific statement of the American Heart Association, which states that treatment with EPA and DHA can reasonably represent a strategy for the prevention of coronary heart disease and sudden cardiac death," said Dr. Kevin Maki of Midwest Biomedical Research, lead author of the study. "A significant advantage of supplementation with EPA and DHA is the low risk associated with their use. Due to the low probability of side effects, even modest benefits are clinically significant," the researcher continued. 

Commenting independently on the meta-analysis results, Bruce Holub, Professor Emeritus at the University of Guelph, emphasized that these suggest most adults could be protected from sudden cardiac death through increased consumption of foods rich in EPA and DHA. The study also showed that the benefits of omega-3 supplementation are greater in regions where consumption of fatty fish containing omega-3 is low, such as North America where the average intake of EPA and DHA per person is only 110-150 milligrams per day. However, the study does not clarify the mechanism through which omega-3 may reduce the risk of cardiac death, but according to researchers, doses above one gram of EPA and DHA may be necessary to produce clinically relevant changes in inflammation and thrombosis mechanisms. 

Dr. Harry Rice, Vice President of Regulatory and Scientific Affairs at the EPA and DHA organization (GOED) that commissioned the research, welcomed the study’s conclusions, highlighting the importance of findings regarding EPA and DHA’s effects on cardiac death. Numerous studies in recent years have highlighted the role of omega-3 in combating cardiovascular diseases, but according to Rice, to understand their role in the cardiovascular system, research must focus on a specific condition such as this meta-analysis. The study is the first of its kind to include cardiac death as the primary outcome of treatment and the most comprehensive review on the topic to date.

Some significant details of the research

The research examined 14 studies published by December 2016, involving a total of 71,899 subjects. The selection of included studies was conducted using major scientific article databases and selecting publications that investigated the effects of omega-3 supplements and drugs, for an intervention period of at least 6 months, on the outcome of cardiac death. 

Among the analyzed subjects, those who had taken omega-3 supplementation and died from cardiac causes were 1,613, while those in the control group (without supplementation) were 1,746. The authors did not examine the effects of consuming fish rich in EPA and DHA on the risk of cardiac death due to lack of studies. However, available data still support the hypothesis of reduced mortality thanks to a diet rich in seafood products.

Omega-3 as a future pharmacological therapy?

According to the researchers conducting the meta-analysis, the data suggest the effectiveness of omega-3 in reducing the risk of cardiac death, and the need for further research to evaluate potential risk reduction with high-dose omega-3 supplementation and in populations with higher mortality risk. 

Future investigations should include assessment of omega-3 markers before supplementation and during treatment, and be designed to test mechanisms through which EPA and DHA may act. Currently, four studies are underway on the risk of cardiovascular events following omega-3 supplementation, which will provide useful additional information on their potential use as pharmacological therapy. 

Source: K.C. Maki 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.