Background: In prospective studies, moderate alcohol intake has been associated with a lower risk of myocardial infarction (MI) compared with no alcohol consumption. This link is thought to be associated with high-density lipoprotein cholesterol levels found in persons who drink moderately. Alcohol consumption usually is not recommended in clinical guidelines because of the risks related to high alcohol consumption. Instead, other lifestyle modifications, such as a proper diet, smoking cessation, and adequate exercise, are emphasized to reduce the risk of MI and coronary heart disease (CHD), despite there being no trials that support weight loss or smoking cessation to reduce these risks. Mukamal and colleagues evaluated alcohol intake and its association with lowered risk of MI in men who reported favorable lifestyle behaviors.

The Study: Participants were men enrolled in the Health Professionals Follow-up Study, which started in 1986. The study included a biennial questionnaire about diet, lifestyle, and medical history. Men without a major medical illness who had adopted healthy lifestyle measures were enrolled in the study. A body mass index less than 25 kg per m², moderate to vigorous physical activity for 30 minutes or more each day, nonsmoking, and a healthy diet were considered healthy lifestyle behaviors.

A healthy diet included multivitamin use; a high intake of vegetables, fruits, cereal fiber, vegetable proteins such as soy and tofu; and a low consumption of trans fats and red and processed meats. Intake of beer, wine, and liquor in the previous year also was recorded. The portion size for alcohol consumption was .45 oz for beer, 0.4 oz for wine, and 0.5 oz for liquor.

The survey asked about the incidence of nonfatal MI and fatal CHD. Positive responses were followed with a review of the participants' medical records; when possible, deaths were confirmed through families, postal officials, and the National Death Index.

Results: Of the 8,867 men who met the inclusion criteria, 106 MIs occurred over the 16-year study. Alcohol consumption of 15.0 g to 29.9 g (approximately two drinks) per day was associated with the lowest risk of MI. The hazard ratio for men who consumed alcohol and exhibited four positive lifestyle behaviors was 0.98 (95% confidence interval [CI], 0.55 to 1.74) for 0.1 g to 4.9 g of alcohol per day; 0.59 (95% CI, 0.33 to 1.07) for 5.0 g to 14.9 g per day; 0.38 (95% CI, 0.16 to 0.89) for 15.0 g to 29.9 g per day; and 0.86 (95% CI, 0.36 to 2.05) for 30 g or more per day.

Men who consumed two alcoholic beverages per day but had only three positive lifestyle behaviors also had a similar reduction in risk of MI.

Conclusion: Moderate alcohol consumption (one half to two drinks per day) is associated with a lower risk of MI in men, even for those already at low risk. The authors add that these recommendations should be considered as a possible complement, not an alternative, to other lifestyle modifications that can reduce the risk of MI.