The ruling, announced by the French food safety authority AFSSA (Agence Française de Sécurité Sanitaire des Aliments) on 3 December, comes just in time for US cranberry group Ocean Spray's launch of its juice drink range in France in spring.

Recurrent cystitis affects 2 million women annually in France and prompts around 5 million calls to doctors. The number of doctors appointments is 2.5 times more than in the US, making the health claim a valuable asset for cranberry product makers looking to expand in this market, which like much of southern Europe is still underdeveloped in terms of cranberry consumption compared to northern populations.

France was however the first country to approve a health claim for the fruit, or indeed any fruit, in a ruling issued in April last year.

But this claim, which said that consumption of certain amounts of the North American cranberry species vaccinium macrocarpon can 'help reduce the adhesion of certain E.coli bacteria to the urinary tract walls', was only relevant to products using the fruit concentrate or extract in powder form, often used in supplements, as it required daily consumption of 36mg.

The extended health claim allows food manufacturers to make the claim for regular consumption of juice drinks or cordials, or 300ml daily of a minimum 27 per cent cranberry juice drink.

The approved quantities are designed to ensure that sufficient amounts of proanthocyanidins (type A) - the components responsible for the cranberry's anti-adhesion mechanism - are available to the consumer to provide the health benefit.

A significant body of research, compiled by Ocean Spray to support the firm's initial petition to AFSSA, shows that these polyphenols stop disease-causing organisms from sticking to the urinary tract walls and causing infection, instead flushing them from the body.

A Canadian study in 2002 found 40 per cent fewer women experienced urinary tract infections when receiving cranberry products compared to those on placebo, and also used less antibiotics.

The same mechansim of action against bacteria could also make cranberries useful in fighting other diseases.

Gunter Haesaerts, managing director of Gika, which distributes Ocean Spray's ingredients in France, said last summer that he was working on another four health claims for the cranberry, such as one to support the fruit's protective action against stomach ulcers through its effect on the Heliobacter pylori bacteria, as well as its anti-adhesive effect on bacteria in the mouth that helps to prevent the build-up of plaque.

Ocean Spray produces 65 per cent of the world's North American cranberries but demand for cranberry products has brought smaller suppliers into the European market.