Two major papers recently reviewed the research about the effect of omega-3 fats from fish or fish oil supplements on the risk of heart disease and came to slightly different conclusions. Previous reviews and meta-analyses on this subject have produced conflicting results.
A meta-analysis published in Mayo Clinic Proceedings in January 2017 looked at 18 clinical trials and 16 observational studies on omega-3 fats and coronary artery disease, notably heart attacks. It found that in the observational studies, which looked mostly at fish consumption, people consuming the most omega-3s had an 18 percent overall reduction in coronary risk. In contrast, the clinical trials, most of which used supplements, found no statistically significant benefit overall, though there was a 15 percent reduction in coronary events, on average, in people at elevated risk because of high LDL (“bad”) cholesterol or high triglycerides.
Then in a scientific advisory published online in the journal Circulation in March 2017, the American Heart Association (AHA) reviewed the clinical research on omega-3 (fish oil) supplements and concluded that only people who have coronary artery disease or heart failure should consider taking them. That goes along with the AHA’s prior recommendation that such people should consume 1,000 milligrams of omega-3s a day, preferably from fatty fish. For those who don’t get enough omega-3s from fish, supplements are a “reasonable” option, after discussion with their doctors, according to the new advisory.
The AHA concluded that there is insufficient evidence from clinical trials to support the use of omega-3 supplements for prevention of cardiovascular disease in the general population; there was no consensus about supplements for people at high risk but no history of cardiovascular disease. The advisory did not address people with very high serum triglycerides, for whom high-dose, prescription omega-3 preparations are approved.