Many studies have found conflicting evidence in fish oil’s effectiveness. (Bigstockphoto)
Fish oil may not help prevent heart attacks and strokes

THE QUESTION Touted for an array of health benefits, fish oil has become one of the more widely taken supplements. Do its heart-protective benefits, which include helping lower blood pressure and triglyceride levels, translate to fewer serious cardiovascular problems such as heart attacks and strokes?

THIS STUDY analyzed data from 20 studies, involving 68,680 adults, most in their 60s, who had been chosen at random to take either fish oil (average dosage, 1.5 grams) or a placebo daily for up to six years. In that time, the studies reported 1,837 heart attacks, 1,490 strokes, 3,993 heart-related deaths and 1,150 sudden deaths. For people who took fish oil, the likelihood of having a heart attack or stroke or of dying suddenly or from a specific heart-related cause was essentially the same as for those who took the placebo.

WHO MAY BE AFFECTED? People who consume fish oil, the shorthand phrase for beneficial oils known as omega-3 fatty acids. Besides its presumed cardiovascular benefits, fish oil is thought to help with depression, rheumatoid arthritis, attention-deficit hyperactivity disorder, osteoporosis, kidney problems, bipolar syndrome, age-related macular degeneration, psoriasis, asthma and more. Many studies have found conflicting evidence on its effectiveness.

CAVEATS Not all studies included data on all outcomes. Participants in two of the studies got fish oil from their diets; in the other 18 studies, they took supplements.

FIND THIS STUDY Sept. 12 issue of the Journal of the American Medical Association.

LEARN MORE ABOUT fish oil at and about supplements at

Linda Searing

The research described in Quick Study comes from credible, peer-reviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician.