The researchers, led by Pierre-Louis Teissedre, chose chardonnay grapes which were rich in polyphenols. They also changed the wine-making process so it was more like that for red wine, including maceration on the skins and a warmer fermentation temperature. The end result was a Chardonnay which had polyphenol levels four times higher than normal.

The wine was designed for people with Type 1 - or juvenile - diabetes, whose bodies are less effective at mopping up free radicals than normal. Tests carried out on diabetic rats showed the wine restored antioxidant levels in the blood back to normal, even if all the alcohol was removed.

But tests have not yet proved it reduces fat deposits in arteries, thereby reducing the risk of heart attacks and strokes. The research has been published in the magazine New Scientist and the online version of the Journal of Agricultural and Food Chemistry.

Dr. Teissedre said a glass or two of the wine a day could benefit people with diabetes. But Eleanor Kennedy of the charity Diabetes UK said: "The best way to get antioxidants is to eat plenty of fruit and vegetables. "People with diabetes should only drink alcohol in moderation." Belinda Linden, head of medical information at the BHF, said: "One to two units of alcohol are thought to provide some protection against coronary heart disease, but large or excessive amounts can be harmful. Red wine has been singled out as beneficial because it contains antioxidants, which can help to lower blood cholesterol levels. However, though it is claimed that red wine contains more antioxidants than other alcoholic drinks, studies are ongoing. There is no definitive proof that red wine is more beneficial than moderate amounts of other types of alcohol, so this new wine may not be very different."

SOURCE: Landrault N et al. Effect of a Polyphenols-Enriched Chardonnay White Wine in Diabetic Rats. Journal of Agricultural and Food Chemistry 2002.