Most of us know that a diet that includes fish can help protect the heart. Fish is rich in omega-3 polyunsaturated fatty acids (PUFAs) which, when taken as a supplement, can protect people with coronary disease from suffering a severe heart attack. But there was always the worry that the supplements might also increase the risk of stroke.
So, if heart patients were to get their omega-3 from fish alone, how much would they need to eat to gain the same protective effect, but without the stroke risk?
Researchers from Harvard Medical School decided to find out, and they recruited 43,000 healthy men aged between 40 and 75 years to find out.
The first piece of good news is that the researchers were able to confirm that fish can deliver the same benefits as supplements. Perhaps more surprisingly, it doesn't take a lot to make a difference. Men who ate fish less than once a month certainly faced a far higher risk of stroke compared with those who ate fish just once to three times a month. But those who ate fish more frequently still, and the researchers assessed some participants who had fish five times a week, did not have any more protection than those who had fish less frequently.
So, on average, a diet that includes fish once a week is sufficient, say the researchers. (Source: Journal of the American Medical Association, 2002; 288: 3130-6).