Do fish oil supplements reduce the risk of heart disease? There are many studies of this question, and they don't all come to the same results. A study published May 9, 2013, in The New England Journal of Medicine found that omega-3s in a fish oil supplement didn't reduce the risk of stroke or heart attack among people with a high heart disease risk. Italian researchers studied 12,500 high-risk people who were already on medications. Half of the study subjects took fish oil supplements; the other half took a placebo (a capsule filled with olive oil). After five years, both groups had the same results: about 12% wound up dying or going to the hospital for heart-related problems. What does this mean for you? "For healthy people trying to prevent heart disease by taking fish oil supplements, while there is no harm, there doesn't appear to be a benefit either," says cardiologist Dr. Deepak Bhatt, a Harvard Medical School professor. He says the door isn't completely shut on fish oil capsules. He's leading a large study of omega-3s and their effect on people with elevated triglycerides. And there's strong evidence that omega-3 fatty acids in your diet does offer protection against heart disease and stroke. Good sources of omega-3s include sardines, mackerel, salmon, flaxseed, walnuts, and canola oil.