Epidemiologic studies show that populations who eat fish versus those who do not have a reduced death rate from cardiovascular disease.

Experimental studies have shown that omega-3 fatty acids affect the function of cells involved in atherothrombosis in numerous ways, including the modification of eicosanoid products in the cyclooxygenase and lipoxygenase pathways, the reduced synthesis of cytokines and platelet-derived growth factor, and alterations of leukocyte and endothelial cell properties. Intervention studies in patients with restenosis, myocardial infarction, and cardiac arrhythmias with omega-3 fatty acid supplementation have been addressed in several clinical studies.

The ingestion of omega-3 fatty acids following one episode of myocardial infarction appears to decrease the rate of cardiac death. These effects of omega-3 fatty acids appear to be due to their antiarrhythmic properties. In fact, fish oil has been shown to reduce ventricular arrhythmias and to be more beneficial than currently used pharmacologic agents.

The dose, duration, and mechanisms involved in the prevention and management of cardiovascular disease following omega-3 fatty acid ingestion or supplementation need to be investigated by double blind controlled clinical trials.