Study swims against the tide of opinion on oily fish health benefits

CLAIMS that oily fish is good for people’s health are not backed by strong evidence, experts said yesterday.

Researchers studied the effects of omega 3 fats on death rates, heart disease and cancer and found there was no evidence of a “clear benefit” of omega 3 fats on health.

In a study published in yesterday’s British Medical Journal, scientists were keen to point out that the importance of omega 3s should not be ruled out.

But they warned that the evidence about potential benefits should be regularly reviewed.

Omega 3 fats are found in oily fish such as mackerel and fresh tuna, supplements and some plant oils.

They have been widely regarded as beneficial for health, with health experts recommending that people eat more of them.

In the BMJ report, researchers analysed 89 studies to assess the effects of omega 3 fats on different outcomes for health.

Pooling the results showed no strong evidence that omega 3s had an effect on total deaths, heart attacks, heart disease, cancer or strokes.

The researchers concluded that it is actually unclear whether omega 3s reduce or increase total death rates, heart attacks and disease, cancer, or strokes.

Guidelines advising people to eat more oily fish should continue for now but the evidence should be reviewed regularly, the authors said.

In an accompanying BMJ editorial, Eric Brunner, said people faced a paradox.

“Health recommendations advise increased consumption of oily fish and fish oils, within limits, on the grounds that intake is generally low.

“However, industrial fishing has depleted the world’s fish stocks by some 90% since 1950, and rising fish prices reduce affordability particularly for people with low incomes.”

Other studies have found that omega 3s have a positive effect on health.

Earlier this week, a study found that the fats helped stop the spread of prostate cancer to other parts of the body.

Dr Mike Knapton, British Heart Foundation director of prevention and care, said people should not stop taking omega 3 fats or oily fish as a result of the study.

He added: “Until now, medical research has demonstrated a benefit from omega 3 fats in protecting people from heart and circulatory disease.

“This systematic review of numerous studies concludes that there is no clear evidence either way.

“More research is needed to establish why some studies have shown a slightly increased risk associated with eating very high amounts of oily fish, which is possibly related to mercury levels,” Dr Knapton said.