A leading nutritionist has called into doubt the benefits of omega-3 supplements, saying most consumers are wasting their money on poor-quality products.

Dr Alex Richardson of the charity Food & Behaviour Research said the low quality of some supplements meant most consumers did not receive the amount of omega-3 their bodies required.

“Surveys show that nine out of 10 Britons don't get the minimum they need to maintain a healthy heart, let alone to support optimal brain and immune system functioning,” Richardson told the Daily Mail.

“There are different kinds of omega-3 – not all of which have the same health benefits. What’s more, at the moment there is no official recommended daily allowance.”

Experts have come to regard the fatty acid, high quantities of which are found in fish and seafood, as a key component in a healthy diet. The UK market for omega-3 supplements is estimated to be around £60m a year.

Last month John West launched a new canned tuna steak containing five times more omega-3 than a standard can, while the new range of frozen food recently announced by former England football captain David Beckham is also enriched with the fatty acid and other vitamins.