Red wine polyphenols explain the French paradox (the French have a high-fat diet, but one of the lowest rates of heart disease). They protect LDL cholesterol from oxidation, they inhibit the proliferation of smooth muscle cells, and they enhance endothelial nitric-oxide synthase activity, which improves the health of the heart and blood vessels.
This activity has been confirmed in a recent study - but, as it's nothing to do with alcohol, you could get all the benefits from a supplement. Dr Whisky would be turning in his grave.
(Source: American Journal of Clinical Nutrition, 2004; 79: 123-30).