A glass of red wine can protect you against a stroke - and now researchers think they know how it works. While scientists already know that resveratrol in red wine - and in the seeds and skin of red grapes - has a protective effect, they have now discovered that it increases the levels of an enzyme that shields nerve cells from damage. As well as protecting against stroke, moderate red wine drinking may also reduce your chances of cardio-vascular disease. And it seems to be the wine that helps deliver the amounts of resveratrol that matter. Researchers at Johns Hopkins University School of Medicine, who carried out the latest research, say that you may not get the same benefits from taking resveratrol supplements or by eating red grapes. (Source: Experimental Neurology, 2010; doi: 10.1016/j.expneurol.2010.03.032).