Coronary heart disease: fewer deaths due to the anti-inflammatory action of Omega-3s

Omega-3s may reduce the likelihood of death from heart disease and more. Daily intake of Omega-3s EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), by patients with coronary artery disease, is associated with a decreased risk of cardiovascular events, sudden cardiac death, and death from other causes. 

This was reported in a meta-analysis study, that is, an analysis of information obtained from multiple independent studies, conducted by researchers at Nanjing University (China), and published recently in the journal Nutrition, Metabolism and Cardiovascular Diseases.

Omega-3 and cardiovascular risk

In the last century, a Danish researcher noticed the low frequency of heart attack deaths among Greenlanders compared to those in Denmark. Comparing their diets, he noticed that the Danish diet was rich in meat, while that of the Eskimos was fish-based. The relationship between Omega-3 rich fish consumption and cardiovascular protection was later confirmed by numerous studies.

Today, the mechanisms by which Omega-3s exert their protective action are also known.EPA and DHA thin membranes and stimulate the release of endothelium, the tissue that lines blood vessels, lowering blood pressure.

They regulate platelet aggregation and inflammation, limiting the formation of atherosclerotic plaques. In addition, Omega-3s reduce the heart's susceptibility to arrhythmia and lower plasma triglyceride levels.

Omega-3s reduce the risk of death

The meta-analysis considered as many as 14 clinical trials of different durations, ranging from 3 months to 4 years, involving a large number of participants. Of these, 16,318, randomly selected, had received a placebo, while 16,338 had taken supplements of DHA, EPA, or both. The participants included in the study had had heart attacks or ischemia, or suffered from heart failure, angina, atherosclerosis, or coronary artery disease. Among those who had taken the supplements, the researchers observed a trend toward reduced risk of major cardiovascular events (heart attack, stroke, ischemia) that was not evident in control subjects. Separate analyses, conducted in patients with coronary atherosclerosis, unveiled a 51 percent reduction in the risk of cardiovascular events in those given Omega-3s, compared with controls. In addition, supplementation with high doses, more than one gram per day, of Omega-3 was associated with a 22 percent reduction in the risk of heart attack, stroke or ischemia. Among those who had received the supplements, the likelihood of dying from heart problems was 13% lower, and that of sudden cardiac death 14% lower, compared with control subjects.Surprisingly, among those who had taken Omega-3, the risk of death from noncardiovascular causes was also 8% lower, compared with those who had received the placebo.

Positive results but to be confirmed

The results of this meta-analysis indicate an association between Omega-3s and reduced death from cardiac and noncardiac problems in patients with coronary artery disease. An effect due to the combined protective actions of EPA and DHA on lipid metabolism, blood pressure, and vascular and cardiac function. However, the role of dietary supplementation with Omega-3 in patients with coronary artery disease is yet to be further investigated with other clinical studies.

Source: 

Wen YT, Dai JH, Gao Q. "Effects of omega-3 fatty acid on major cardiovascular events and mortality in patients with coronary heart disease: A meta-analysis of randomized controlled trials" Nutr Metab Cardiovasc Dis. 2013 Dec 25. pii: S0939-4753(13)00308-6.

 doi: 10.1016/j.numecd.2013.12.004