Fish oil supplements 'do not protect the heart': Cochrane review

Findings are at odds with popular belief about omega-3 fatty acids

Omega-3 supplements don’t reduce the risk of cardiovascular events or mortality, according to a Cochrane review billed as the most extensive assessment of the evidence to date.

fish oil supplements

The review of 79 randomised trials covering more than 112,000 individuals found that increasing intake of omega-3 fatty acids from supplements or foods has little or no effect in improving heart and circulatory health or reducing all-cause mortality.

Most of the trials assessed the effects of consuming omega-3 supplements compared with normal dietary consumption of polyunsaturated fatty acids for primary and secondary prevention of cardiovascular disease.

The specific nutrients examined included eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oils and alpha-linolenic acid (ALA) from plant foods.

“There is evidence that taking omega-3 capsules does not reduce heart disease, stroke or death,” the authors concluded.

“Although EPA and DHA reduce triglycerides, supplementary omega-3 fats are probably not useful for preventing or treating heart and circulatory diseases.”

Eating more ALA made little or no difference to all-cause or cardiovascular deaths, or coronary events, but could potentially play a protective role in some heart and circulatory diseases.

Cochrane lead author Dr Lee Hooper said the reviewers could be confident about their findings, which are at odds with the popular belief that fish oils protect the heart.

“This large, systematic review included information from many thousands of people over long periods,” said Dr Hooper, a dietitian and nutritionist from the University of East Anglia, UK. “Despite all this information, we don’t see protective effects.”

The Heart Foundation currently recommends Australians consume omega-3 fats from fish, plants, nuts and animal products, but says fish oil supplements can be beneficial for people with high triglycerides.

“[The Cochrane review] aligns with the Heart Foundation’s current position, which does not advise that health professionals routinely recommend omega-3 supplements for heart health,” chief medical adviser Professor Garry Jennings said.

“However, omega-3 supplements can be of value in people with high triglyceride levels and there is some evidence for considering their use in heart failure.”

Source: Cochrane Database of Systematic Reviews 2018; Issue 7.