Claims already rejected include the claim that cranberry juice can reduce the risk of urinary tract infection in women.

The Nutrition and Health Claims Regulation (adopted back in 2006, but only recently taking proper effect) demands that advertisers provide scientific evidence to back up their claims. The Regulation covers a wide array of health products – from vitamins and diet pills to margarine and probiotic yoghurts – and means that a producer such as Yakult must satisfy authorities that its claims are scientifically proven before it can be permitted to run with them.

If current figures are anything to go by, such producers have a lot to be worried about: of the 900 claims so far examined, a whopping 80% have been rejected because of insufficient scientific evidence to back the claims made.

Unsurprisingly, the industry has reacted negatively to the news. Jenny Baillie of York-based health foods company Power Health has stated that, as a result of the regulation, “people will probably start buying in from unregulated countries…and we could well end up with customers less protected than they were.”

But not all quarters have treated the regulation with contempt. Unilever, which produces such health brands as Flora pro.activ and Slim Fast, released a statement saying the new regulation would provide a scientific standard and enable “consumers to make informed and meaningful choices they can trust”.

By James Kemp