The mystery of why drinking red wine is good for you may have been solved by scientists at the University of Virginia Health System, who claim it is all down to a compound called resveratrol.

The research found that resveratrol helps to starve cancer cells by inhibiting the action of a key protein that feeds them. The protein, called nuclear factor- kappa B (NF-kB), is found in the nucleus of all cells and activates genes responsible for cell survival.

"We used physiologically-relevant doses of resveratrol and found dramatic effects on human cancer cells," said Marty Mayo, assistant professor of biochemistry and molecular genetics at U.Va.

Mayo said that the resveratrol in one glass of wine three or four times a week is the right amount to block the protein from feeding cancer cells. Drinking much more than that, however, could stop this affect and, in fact, lead to a greater risk of cancer, he said.

The findings, discovered by Fan Yeung, a postdoctoral fellow at U.Va., are published in the May 20 online edition of the Journal of the European Molecular Biology Organization (EMBO).