Fish oil has garnered a reputation as a heart-healthy supplement. It may — stress the "may" — help prevent heart disease. But the results of four recent randomized, controlled trials (the gold-standard of medical research) showed that fish oil didn't work any better than a sugar pull at preventing recurring heart problems among heart attack survivors or people with atrial fibrillation, reports the March issue of the Harvard Heart Letter.

These findings contradict findings from the 1990s that suggested fish oil could protect damaged hearts. But those trials were done before the widespread use of heart-protecting medications such as statins, ACE inhibitors, aspirin, and beta blockers. In their absence, fish oil by itself could have made a difference. In the four most recent trials, participants took fish oil on top of state-of-the-art medical therapy. Use of heart-protecting medications could have drowned out any small benefit from fish oil.

These findings don't mean fish oil is a complete flop. It may work against heart disease if started earlier, before coronary arteries sustain much damage from cholesterol or high blood pressure. And it is a good treatment for high triglycerides. But if you already have heart disease, eating fish is a better option than taking fish oil. What if you just don't like fish? Make sure that your doctor has prescribed the best medical and lifestyle therapies for your condition—and that you are following his or her advice.

Read the full-length article: "Fish oil questioned as treatment for heart disease"