3. The favorable effect is seen very rapidly, usually by three months into the study. This contrasts with most studies of statins, the most widely used class of drug for lowering cholesterol levels, where the favorable effect on death rates is not usually seen until after a year or more of therapy. It is almost certain that omega-3 fatty acids provide benefit by a mechanism completely different from that of traditional cholesterol-lowering drugs, and it is likely that combination of the two will provide greater benefit than either alone.
4. The dose of omega-3 fatty acids needed to provide these benefits is small, the equivalent of two fatty fish meals a week. In capsule form, a total dose of 800 milligrams to 1,000 milligrams of omega-3 fatty acids per day should be sufficient. Capsules in the United States contain either 300 milligrams or 500 milligrams of omega-3 fatty acids per capsule.
5. As compared to traditional drug therapy, omega-3 fatty acids provide remarkable benefits, are entirely safe, and are inexpensive.
Should you take omega-3 fatty acids?
All of the evidence suggests that all patients with known heart or other vascular disease would benefit from taking omega-3 fatty acids, either as a cold water fish meal at least twice a week or as a supplement.
It is also likely that patients without known heart disease but who are at high risk because of factors such as elevated cholesterol, high blood pressure or diabetes also would benefit from this approach. Even individuals who are not at increased risk can reduce their risk of death from heart attack by substituting fish for meat high in saturated fat.
However, if you have had a stroke you should discuss the use of omega-3 supplements with your physician — some strokes are caused by bleeding into the brain, and omega-3 supplements, because they cause a slight increase in the likelihood of bleeding, should not be used in this situation.
Why hasn't my doctor told me this?
It is not clear why most physicians have not picked up on the very strong evidence that was already available before this week's studies.
Why physicians were so quick to recommend agents such as vitamin E — which never had very strong evidence backing its use and which has now had several negative studies — and at the same time were reluctant to recommend omega-3 fatty acids when the data favoring their use has been so strong is a mystery.
It is to be hoped that more physicians will now recommend these effective, safe, and inexpensive agents. Ockene is the David and Barbara Milliken professor of preventive cardiology, the director of the Preventive Cardiology Program, and the associate director of the division of cardiovascular medicine at the University of Massachusetts Medical School.