The idea that light to moderate alcohol drinking protects against heart disease has become entrenched, but findings from a new study challenge this.

Analyzing data from a decade-long study, researchers found that alcohol consumption was associated with a lower risk of heart disease, but only among whites. Among black men, the opposite was true - alcohol consumption was associated with an increased risk of heart disease and death from heart disease.

This does not mean that the heart-protective effects of alcohol drinking depend on the race of the drinker, according to study author Dr. Flavio Fuchs of Federal University of Rio Grande do Sul in Brazil told Reuters Health.

“We believe that there is not a race-specific effect of ethanol,” he told Reuters Health. “There is no scientific background to suppose that blacks would respond so differently to ethanol.”

Rather, the researchers say in their report in the American Journal of Epidemiology, the contrasting findings between blacks and whites “raise the question of whether the cardioprotective effect of alcohol is real or may be confounded by lifestyle characteristics of drinkers.”

The study’s results cast doubts on the idea that people should drink alcohol as a preventive health strategy to protect against heart disease. “Moderate consumption of alcohol does not increase the risk for a heart attack…but it is not clear if it protects against a heart attack,” Fuchs said.

This is important, he added, because “there is a trend in some countries to recommend the consumption of low amounts of alcoholic beverages to get some heart protection.”

Fuchs and his colleagues analyzed data from 14,506 black and white participants in the on-going Atherosclerosis Risk in Communities Study. The participants were asked about their alcohol drinking habits - whether they were current or former drinkers and the typical number of drinks they consumed per week - and were followed up for about 10 years.

About 55 percent of white men and 34 percent of white women said they were current drinkers, in comparison to 45 percent of black men and 15 percent of black women.

During the follow-up period, 707 people were hospitalized for a heart attack or experienced some other heart disease-related event. Of these, 146 people died, Fuchs and his colleagues report.

The incidence of heart disease-related events among current drinkers was higher among blacks than whites.

For example, black men were 13 percent more likely to experience heart disease for every 13 grams of ethanol (about 12 ounces of beer) consumed every day, whereas white men who drank the same amount were 22 percent less likely to develop heart disease.

Further, black men who consumed between 140 and 210 grams of ethanol each week - equivalent to about 13 to 19 glasses of wine, for example - were more than twice as likely as their non-drinking peers to have heart disease. In contrast, white men who drank similar amounts were nearly half as likely to experience heart disease as white men who did not drink.

White women who drank only on rare occasions, as was the case for 27 percent of them, were 53 percent less likely to experience heart disease than were their non-drinking peers. Those who said they were current drinkers and consumed 70 or more grams of ethanol on a weekly basis had a similarly reduced risk of heart disease. No conclusions could be drawn among the black women, the authors note, since so few reported current or rare drinking.

The reason for the discrepancy between blacks and whites is unknown, Fuchs said, but white men may have “an overall lower risk profile.”

The bottom line? “Moderate wine, and probably beer and liquors, are not harmful, but may not protect our health,” Fuchs said.

SOURCE: American Journal of Epidemiology, September 1, 2004.