Taking omega-3 fish oil supplements do not provide benefits for people with type 2 diabetes, but they are not harmful either, University of East Anglia (UAE) researchers have concluded.

Omega-3 is a type of fat that can be beneficial for people’s overall health and has been linked with potentially preventing obesity and type 2 diabetes. It is abundant in oily fish sources such as salmon and sardines.

Taking vitamins has been promoted as being a positive approach to health, although there had been unconfirmed evidence that omega-3 supplementation might negatively affect glucose metabolism for people with type 2 diabetes.

So, the World Health Organization commissioned a systematic review to be carried out to further explore how omega-3 may impact people with type 2 diabetes.

More than 80 studies were looked at, and over 58,000 participants were reviewed and 4% in total developed type 2 diabetes. Those who were randomly assigned to consume more omega-3 had the same risk of diagnosis as the control group who did not consume more fish oil.

Joint first author, Dr. Julii Brainard, from Norwich Medical School, said: “Oily fish can be a very nutritious food as part of a balanced diet, but we did not find enough trials that encouraged participants to eat more oily fish to know whether it is useful in preventing diabetes or improving glucose metabolism.

“What we did find is that there is no demonstrable value in ordinary people taking omega 3 oil supplements for the prevention or treatment of [type 2] diabetes.

“We would also have liked to find out whether taking more omega-3 might be useful in those people with low omega-3 intakes – as giving more omega-3 is more likely to be useful in adults with low intakes. But unfortunately most trials didn’t report omega-3 intake levels of participants at the start of the trial, so we still don’t know.”

Douglas Twenefour, deputy head of care at Diabetes UK, said: “While omega-3 fatty acids are crucial for our overall health, it’s generally better for people with type 2 diabetes to get their intake by eating at least two portions of oily fish a week, than by taking supplements.”

The findings have been published in The BMJ.

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