New research in Britain suggests that claims that eating oily fish can reduce the risk of heart disease and cancer are not backed by strong evidence.
Scientists analysed 89 studies to assess the effects of omega-3 fats on different outcomes for health.
They found there was no evidence of a clear benefit.
However, in a study published in the British Medical Journal, experts were keen to point out that the importance of omega-3s should not be ruled out.
The fats are found in oily fish such as mackerel, salmon and fresh tuna as well as supplements and some plant oils.
