The next pill in the firing line is fish oil. Also known as omega-3, fish oil has been widely publicised as being protective against heart disease, but according to a new Cochrane review, led by the University of East Anglia, the supplements offer little benefit to those taking them.
Omega-3 fats like alphalinolenic acid (ALA), eicosapentaenoic acid, and docosahexaenoic acid, are certainly good for you, because they are essential for our health.
But the review, which combined the results from 79 different trials, involving over 112,000 people, found that omega-3 supplements like fish oils didn't seem to protect the heart.
Participants were randomly assigned to either increase their omega-3 fat intake, or maintain their usual amount of fat in their diet for a year, then they were assessed for diseases of the heart and circulation.
Results showed no significant difference in death rates, with 8.8% of people taking omega-3 dying compared to 9% of those in control groups. There was also no significant difference in the rates of heart attacks or strokes.
Lee Hooper, a researcher at UEA's Norwich Medical School, who led the study, said the results show there is little evidence that omega-3 pills benefit the heart, or reduce the risk of death from any cause.
She told The Times it's much better to include oily fish in your diet rather than take supplements, because it's not just the omega-3 you're ingesting.
"You're also getting a protein source that replaces something else in your diet like saturated fat, and seafood has selenium, iron and vitamin D. All of these are useful nutrients," she said.
She added that the review did find some evidence that one omega-3 fat alphalinolenic acid (ALA), found in rapeseed or canola oil and walnuts, may be slightly protective against heart and circulation diseases.
"However, the effect is very small," she said. "143 people would need to increase their ALA intake to prevent one person developing arrhythmia. One thousand people would need to increase their ALA intake to prevent one person dying of coronary heart disease or experiencing a cardiovascular event."
Fish oil seems to have been blown up in our health estimations for a long time. Over a decade ago, 3,000 children in Durham were given fish oil to see if it improved GCSE performance. Academics, including journalist and doctor Ben Goldacre, pointed out this wasn't how a scientific study should be conducted — there was no control group, and it would likely produce false positive results.
The results were further skewed by the fact over 2,000 children dropped out of the trial. But this didn't stop journalists picking up on the line that "832 pupils had 80% or greater compliance".
Journalists also jumped on a story that suggested omega-3 improved school performance and behaviour in children, despite no paper saying anything of the sort.
This isn't to say omega-3 is useless for everything. It's a staple of our diet, just as many vitamins and minerals are. But what's becoming increasingly clear is that if you're looking for a magical supplement pill to work wonders on your health or mental agility, you probably won't find one.
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