Data from a large cohort study has found that alcohol intake is associated with more than a 30% lower incidence of CHD in men.

A total of 15,630 men and 25,806 women, aged 29-69 years, from the European Prospective Investigation into Cancer (EPIC) Spanish cohort were studied. Medium follow-up was 10 years. Alcohol intake was calculated using a validated dietary history questionnaire reporting how many glasses of beer, cider, wine, sweet liquor, distilled spirits, or fortified wine participants consumed per day or week during the 12 months before they were recruited into EPIC.

Participants also provided information on exercise, tobacco use, and other risk factors for heart disease, such as obesity and high cholesterol levels. This allowed adjustment of the results for these other variables.

All participants were free from CHD at baseline. During 10 years of follow-up, there were 609 coronary events, 481 in men but only 128 in women.
Moderate, high and very high alcohol consumption was associated with a reduced risk of CHD in men with a hazard ratio of 0.90 (95% CI: 0.56-1.44) for former drinkers, 0.65 (95% CI: 0.41-1.04) for low, 0.49 (95% CI: 0.32-0.75) for moderate, 0.46 (95% CI: 0.30-0.71) for high and 0.50 (95% CI: 0.29-0.85) for very high consumers.

Women also benefited from alcohol intake, but the effects did not reach statistical significance probably because of the small number of coronary events in this group.

Therefore in men aged 29-69 years, alcohol intake was associated with a more than 30% lower incidence of CHD. This finding clearly supports the idea that alcohol may have a cardioprotective effect.

However, this was not an interventional study and if people who report drinking more have less heart disease that does not mean that drinking necessarily lowers risk for heart disease. I doubt that a randomised trial to answer this question would ever meet ethical approval so we will just have to make do with such observational studies.