Clinical trial evidence for the cardioprotective effects of omega-3 fatty acids.

The notion that marine omega (w)-3 fatty acids might have beneficial cardiovascular effects was first suggested by epidemiologic studies in Greenland Inuits published in the late 1970s. These simple observations spawned hundreds of other studies, the confluence of which strongly suggests a true cardioprotective effect of w-3 fatty acids. The strongest confirmation has come from the publication of three randomized clinical trials, all of which reported benefits to patients with preexisting coronary artery disease. The most convincing of these was the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico (GISSI)-Prevezione study, in which 5654 patients with coronary artery disease were randomized to either w-3 fatty acids (850 mg/d) or usual care. After 3.5 years, those taking the w-3 fatty acids had experienced a 20% reduction in overall mortality and a 45% decrease in risk for sudden cardiac death. These findings support the view that relatively small intakes of w-3 fatty acids are indeed cardioprotective, and suggest that they may operate by stabilizing the myocardium itself.