According to a new study, despite the positive effects on cardiovascular systems of moderate alcohol consumption, seniors with aging hearts who consume two or more drinks a day may be doing some damage to their hearts.

The study, led by Alexandra Goncalves, MD, PhD, correlated the weekly alcohol consumption of almost 4,500 subjects with an average age of 76 to the size, structure and function of the heart.  It is well known that heavy drinking can cause cardiomyopathy, but the influence of moderate drinking on cardiac structure is largely unknown.

For the study, researchers classified the patients into four categories - nondrinkers, drinkers of less than 7 drinks, drinkers of between 7 and 14 drinks, and greater than 14 drinks.  Over half of the subjects were nondrinkers.

The nondrinkers were more likely to be women with higher body mass index and nondrinkers of both sexes were usualy older with lower educational and income levels.  They were also more likely to have diabetes lower LDL cholesterol and HDL cholesterol.  The drinkers in the highest category were most often smokers and had higher LDL and HDL levels.

The investigators reported subtle cardiac alterations in both genders. In women and men, escalating alcohol intake was associated with larger left ventricular (LV) diastolic and systolic diameters and larger left atrial diameter (P<0.05). In men, increasing alcohol intake correlated with greater LV mass (8.2 + 3.8 g per category,P=0.029), a higher tricuspid annulus peak systolic velocity, and a higher E/E' ratio (0.82 + 0.33 per category, P=0.014), suggesting increasing diastolic pressures.

"In spite of increasing LV end-diastolic diameter, no significant increase in LV volumes was observed in either men or women according to alcohol intake," the authors wrote. While the number of black participants was relatively small, especially at the higher end of the consumption spectrum, they observed a significant interaction between race and alcohol intake in men for LV end-diastolic diameter, with greater increases in black men than white at the same consumption level (P=0.008).

"Women appear more susceptible than men to the cardiotoxic effects of alcohol, which might potentially contribute to a higher risk of alcoholic cardiomyopathy, for any given level of alcohol intake," says senior author Scott Solomon, MD, a professor of medicine at Harvard Medical School, in an American Heart Association news release.

"In spite of potential benefits of low alcohol intake, our findings highlight the possible hazards to cardiac structure and function by increased amounts of alcohol consumption in the elderly, particularly among women" Goncalves says. "This reinforces the U.S. recommendations stating that those who drink should do so with moderation." Moderate drinking is generally defined as two alcoholic beverages a day for men and one for women.

Researchers admit there are limitations to this study as it cannot establish causality between alcohol and cardiac alterations and since the alcohol use was self reported, it could be under-reported.