This study has been making the rounds lately in the news. The evidence as analyzed in the article supports the assertion that moderate drinking is cardioprotective in middle age.
What I have not seen in the reviews of the article are mentions of which kind of alcohol are significantly protective. (Perhaps because people are just reviewing the abstract, and not the paper.) This paragraph from the results is revealing:
After adjustment for demographic and cardiovascular risk factors, wine-only drinkers were significantly less likely to have had a subsequent cardiovascular event than nondrinkers (OR 0.32, 95% CI, 0.12-0.87). Consumers of moderate amounts of beer/liquor/mixed (which includes some wine) tended to also be less likely to have had a subsequent cardiovascular event than nondrinkers (OR 0.79, 95% CI, 0.49-1.26), but the difference was not significant.
Emphasis mine. The evidence supports the assertion, then, that it is not alcohol that is protective, but wine. The authors astutely state this in the discussion:
This study’s finding that new wine drinkers experienced a significant reduction in cardiovascular events after 4 years while new drinkers of other alcoholic beverages did not, is consistent with recent studies showing a slight advantage to wine drinkers.