Fish oil, approved in Spain, France and Britain as a prescription, helps prevent sudden death in people who have had heart attacks.
The 3.5-year GISSI study of 11,323 patients who had a heart attack showed that 1 gram of fish oil daily lowered their risk of having a second heart attack, stroke or dying.
The fish oil in the trial contained eicosapentaenoic acid (EPA) ethyl ester: 465 mg and docosahexaenoic acid (DHA) ethyl ester: 375 mg. This is available by prescription, and in over the counter dietary supplements: read the label.
More fish oil–4 grams per day–can lower high triglyerides.
A New York Times piece on fish oil highlights this 15 year old data, which helps it get the circulation it deserves.