'Functional foods' prompt warning

Foods that claim to improve health and well-being should be the subject of tougher checks, say Dutch scientists.

The public health experts said not enough was known about the long-term effects of "functional foods", such as spreads that claim to cut cholesterol.

They expressed concern at the possible effect on those taking medicine, the British Medical Journal reported.

It comes after a boom in the foods - over four months in 2005 some 200 products were launched in the UK alone.

Regulators and policymakers are right to keep an eye on functional foods Professor Tim Lang City University

Other examples of popular "functional foods" are yoghurts that contain bacteria designed to improve digestion.

While stressing that they have no evidence of any health problems for consumers, the team from the National Institute for Public Health and the Environment pays particular attention to products enriched with phytosterol and stanol.

These plant chemicals are intended to work in the gut to prevent the absorption of so-called "bad" cholesterol, thus helping people with mildly elevated cholesterol levels.

Researchers said that while many of those with slightly raised cholesterol levels would probably be unaware of the problem, people with more seriously raised levels would be more inclined to buy and use the product.

This group of consumers is far more likely to already be taking medication for high cholesterol, and this raises the possibility of a clash between the functional food and the drug involved, they said.

'Quick fix'

They wrote: "Very little is known about exposure, long term or otherwise, and safety under free conditions of use, and whether and how functional foods interfere with drugs designed for the same target."

They called for a systematic monitoring programme to help scientists decipher any long term effects of these foods.

Tim Lang, professor of food policy at City University in London, said that "functional foods" were at best a "technical fix", masking an underlying poor diet - and they would make it harder for nutrition experts to work out the effects of good and bad diets on the public.

He said: "Regulators and policymakers are right to keep an eye on functional foods."