Although alcohol is known to be a cardiac toxin, consumption of up to seven drinks per week in early to middle age was found to be associated with a decreased risk of future heart failure in a study published by the European Society of Cardiology.
“Although heavy alcohol consumption is associated with impairment in left ventricular function and eventual alcoholic cardiomyopathy with symptomatic HF, moderate alcohol intake could, conversely, lower the risk for HF,” wrote Dr. Alexandra Gonçalves of Brigham and Women’s Hospital, Boston, and her associates. “However, the association between moderate alcohol intake and the risk of heart failure is still controversial, as some studies did not find an association and the cardiovascular mechanisms of potential benefit of alcohol consumption in heart failure are uncertain” (Eur. Heart J. 2014 [doi:10.1093/eurheartj/ehu514]).
From the ongoing, prospective, observational Atherosclerosis Risk in Communities (ARIC) Study, the investigators analyzed 14,629 subjects aged 45-64 years, 55% of whom were female, and 74% of whom were white. Baseline data for all subjects were taken between 1987 and 1989, and no participants reported prevalent heart failure.
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Self-reported alcohol consumption was assessed at baseline as the weekly number of drinks, with one drink equaling 14 grams of alcohol, and updated cumulative average alcohol intake was calculated over roughly 9 years. Subjects were placed into one of six groups: former drinkers, abstainers, drinkers of less than 7 drinks per week, drinkers of 7-14 drinks per week, drinkers of 14-21 drinks per week, and those who had 21 or more drinks per week. Using multivariable Cox proportional hazards models, investigators analyzed relationships between alcohol consumption and heart failure and whether those associations were affected in any way by the subjects’ sex.
Results showed that 61% of participants reported consuming no alcohol at all – 19% being former drinkers and 42% abstainers – while 25% of participants said they drank up to 7 drinks per week, 8% between 7 and 14 drinks per week, 3% between 14 and 21 drinks per week, and 3% 21 or more drinks per week. Among former drinkers, there were 376 incident heart failure events in men and 266 in women. Among abstainers, there were 333 for men and 717 for women. Rates per 100 person-years equaled 1.50, 1.12, 1.02, and 0.79, respectively.
For subjects who consumed fewer than seven drinks weekly, there were 281 heart failure incidents among men and 191 among women, for rates per 100 person-years of 0.77 and 0.53, respectively, significantly lower than the rates for abstainers. In the higher drinking categories, no significant differences in heart failure rates, compared with abstainers, were observed.
“We observed that participants who consumed up to 7 drinks/week of alcohol had a lower risk of incident HF compared with abstainers, with a less pronounced association in women than in men,” concluded Dr. Gonçalves and her coinvestigators, adding that they “did not find significant differences between white and black men and women in the risk of HF by alcohol consumption [but] once men and women were stratified by race, the number of cases was relatively small in each category of alcohol intake, limiting our ability to detect small differences by race.”
This study was funded by the National Heart, Lung, and Blood Institute, with support from the Portuguese Foundation for Science and Technology Grant and the Ellison Foundation. The authors declared no relevant financial disclosures.