The headline-grabbing study comes from the Cochrane group, which took another look at 79 previously-published studies that involved more than 112,000 people. They found there was no difference in the risk of death or heart disease between people who were taking omega-3 supplements and those who weren't.
The supplements contain EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), known as long-chain omega-3 fats, which are found in oily fish, and are routinely taken to reduce the risk of heart disease. Another type of omega-3 fats—ALA (alphalinolenic acid, found in plants, nuts and seeds—had a small protective effect.
Taking the supplements "makes little or no difference to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke or heart irregularities," the researchers conclude.
Not the conclusion of a research group in China, which analysed an even larger group of 421,000 people and concluded that long-chain omega-3 fatty acids had a definite protective effect against heart disease death and reduced the risk by 15 per cent in men and 8 per cent in women. Eating fish also reduced the risk of cancer by 6 per cent, lung disease death by 20 per cent, and death from chronic liver disease by 37 per cent, researchers from Zhejiang University School of Medicine found.
But it does depend on how you prepare the fish. Boiling or steaming the fish seems to retain its health-giving benefits whereas people who ate only fried fish were just as likely as people who didn't eat any fish to suffer from heart disease.
(Sources: Cochrane study: www.cochrane.org/news/new-cochrane-health-evidence-challenges-belief-omega-3-supplements-reduce-risk-heart-disease; Chinese study: Journal of Internal Medicine, 2018; doi: 10.1111/joim.12786)