 Are purported benefits of fish oil supplementation for the prevention and treatment of heart disease just a fishtail? Thanks to recommendations like this from the American Heart Association that individuals at high risk for heart disease ask their physicians about fish oil supplementation, it's grown into a multi-billion dollar industry. We now consume over 100,000 tons of fish oil every year. But what does the latest science say? A systematic review and meta-analysis published in the Journal of the American Medical Association looked at all the best randomized clinical trials of valuing the effects of omega-3s on lifespan, cardiac death, sudden death, heart attack, and stroke, either advice to eat more oily fish or to take fish oil capsules. What did they find? Overall, they found no protective benefit for overall mortality, heart disease, mortality, sudden cardiac death, heart attack, or stroke. What about for those who've already had a heart attack, though, and are trying to vent another one? Still, no benefit. Where did we even get this idea that omega-3s were good for the heart? Well, if you look at some of the older studies, the results looked promising, for example, the famous Dart trial back in the 80s involving 2,000 men. Those advised to eat fatty fish at a 29% reduction in mortality. Pretty impressive. No wonder it got a lot of attention. But people seem to have forgotten about the sequel, the Dart II trial. Same group of researchers and even bigger study, 3,000 men, and those advised to eat oily fish, and particularly those supplied with fish oil capsules, had a higher risk of cardiac death. Put all the studies together, and there's no justification for the use of omega-3s as a structured intervention in everyday clinical practice, or for guidelines supporting more dietary omega-3s. So what should doctors say when their patients follow the American Heart Association advice to ask them about fish oil supplements? Well, given the new meta-analysis and other negative meta-analyses, our job as doctors should be to stop highly marketed fish oil supplementation in all of our patients.