New Health Warning on Omega-3 Fatty Acids

You've heard that omega-3 fatty acids have many health benefits -- and for most people, they do. They're found in fatty, cold-water fish (salmon, mackerel, lake trout, herring, sardines and albacore tuna), canola, soybean, flaxseed and walnut oils, as well as dark green leafy vegetables like kale and collard greens. You can also get omega-3s from fish-oil capsules (buy the ones with the pollutants removed).

Studies have shown that daily consumption of omega-3s may dramatically reduce the incidence of sudden cardiac death. They may reduce triglycerides, lower blood pressure and decrease inflammation. They can help prevent excessive blood clots from forming which, in turn, may decrease the risk of a heart attack. They may also reduce depression and help prevent dementia. However, I've recently learned that omega-3s are a double-edged sword. The pioneering research of Alexander Leaf, MD, at Harvard Medical School has found that in some cases omega-3s could be fatal.

One of the reasons omega-3s may decrease the incidence of sudden cardiac death is that they stop those cardiac cells that are the most unstable from functioning. But in people who have angina (chest pain or tightness due to heart disease) or congestive heart failure because their hearts are not receiving enough blood flow, removing those cells from functioning can reduce the heart's ability to pump blood so much that it may increase the risk of sudden cardiac death.

My advice: Avoid omega-3s if you have recurrent angina, congestive heart failure or evidence that your heart isn't receiving enough blood flow when you exercise. If you have heart disease or have had a heart attack but don't have angina or congestive heart failure, omega-3s are beneficial. I take 3 grams of fish oil every day.