Two Drinks Called Potent Addition to Heart-Healthy Lifestyle

BOSTON, Oct. 26 -- A couple of drinks -- liquor, wine, or beer -- added daily to an already heart-healthy daily lifestyle further reduces the risk of myocardial infarction in otherwise healthy men, found researchers here.

Previous studies have linked moderate drinking to reduced risk of cardiovascular events, but in those studies it was unclear whether the benefit was from alcohol or some unmeasured, confounding factor, said Kenneth J. Mukamal, M.D., M.P.H., of Beth Israel Deaconess Medical Center and the Harvard School of Public Health, and colleagues.

To quell those lingering doubts, this study "focused on a tightly restricted group of participants, that is, nonsmoking male health professionals with healthy diets, regular vigorous physical activity, and normal body weight."

Compared with non-drinking men who followed a healthy life style, men who consumed an average of two alcoholic beverages a day were roughly 60% less likely to have an MI over 16 years of follow-up, they reported in the Oct. 23 issue of Archives of Internal Medicine.

In this 8,867 cohort of healthy men who participated in the Health Professionals Follow-up Study, compared with abstention, the hazard ratios for MI in a multivariate model adjusted for age, parental history of myocardial infarction, regular aspirin use, and history of hypertension or hypercholesterolemia were:

• 0.98 (95% confidence interval, 0.55-1.74) for alcohol intake of 0.1 to 4.9 g/day (less than half a drink per day)
• 0.59 (95% confidence interval, 0.33-1.07) for alcohol intake of 5.0 to 14.9 g/day (up to one drink per day)
• 0.38 (95% confidence interval, 0.16-0.89) for alcohol intake of 15.0 to 29.9 g/day (one to two drinks per day)
• 0.86 (95% confidence interval, 0.36-2.05) for alcohol intake of 30.0 g/day or more (more than two drinks per day).

The P value for the trend was 0.04.

With residual confounding thus minimized, the authors wrote that it was "unlikely, but not impossible, that an unknown confounding factor is sufficiently strongly associated with both alcohol use and risk of MI to have produced these findings."

All 8,867 men reported four healthy lifestyle behaviors, including a body mass index of less than 25, moderate to vigorous activity for at least 30 minutes a day, and abstention from smoking They also reported a summary diet that indicated they followed a diet rich in fruits, vegetables, and fish and low in transfats, and red or processed meats as well as multivitamin use. Diet, exercise, and alcohol consumption were obtained from baseline questionnaires.

Participants were contacted every four years from the baseline assessment in 1986 through January 31, 2002. Participants who reported an MI at follow-up were contacted and asked for permission to review medical records.

Over 16 years there were 106 incident MIs, and 89 occurred in men who abstained from alcohol or who drank less than half a drink a day.

The study was limited by its inability to assess the effects of "specific drinking patterns, changes in alcohol intake over time, the modifying effect of drinking with meals, or differences among individuals beverage types," the authors wrote.

And although there were enough events to provide statistical power, the confidence intervals were wide, they noted.

They concluded that the findings make a case that "future guidelines for moderate drinking need not consider healthy lifestyle behaviors as mutually exclusive and should instead focus on the strengths and limitations of the evidence about moderate alcohol intake."