Advice to eat oily fish or take fish oil to lower risk of heart disease, stroke, or mortality is no longer supported by the balance of available evidence.
Are purported benefits of fish oil supplementation for the prevention and treatment of heart disease just a fish tale? 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 multibillion dollar industry. We now consume over 100,000 tons of fish oil every year.
But what does the 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 evaluating the effects of omega-3’s 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 already had a heart attack and are trying to prevent another? Still no benefit. Where did we even get this idea that omega 3’s 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 80’s involving 2000 men. Those advised to eat fatty fish had a 29% reduction in mortality. Pretty impressive; no wonder it got a lot of attention, but people seemed to have forgotten about the sequel, the DART-2 trial. Same group of researchers, an 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 3’s 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? Given this and other negative meta-analyses, our job as doctors should be to stop highly marketed fish oil supplementation in all of our patients.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Ariel Levitsky.
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I’ve previously discussed fish oil supplements in the context of risks versus purported cardiovascular benefits:
But if the benefits aren’t there, then all one is left with are concerns over the industrial pollutants that concentrate in the fish fat (even in distilled fish oil, see Is Distilled Fish Oil Toxin-Free?).
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