Study Finds That Moderate Drinkers May Have Lower Risk Of Mortality After A Heart Attack

In the April 18 issue of the Journal of the American Medical Association, the researchers report that moderate drinkers had a 32 percent lower risk of dying from a heart attack than those who didn’t drink alcohol. Moderate drinkers were defined as people who drank at least 7 drinks a week (14 alcoholic beverages a week on average). Light drinkers, or those who had fewer than seven drinks a week, had a 21 percent lower risk. The findings were similar for both men and women.

“Our study does not answer the question whether alcohol is good for you,” says Kenneth J. Mukamal, M.D., M.P.H., an associate physician at Beth Israel Deaconess Medical Center and lead author of the study. “For moderate drinkers these findings are consistent with a lower risk of death from drinking a limited amount of alcohol. But we don’t know if people who are non-drinkers would also have a lower risk of death if they start drinking alcohol.”

The study was conducted at 45 hospitals in the United States between 1989 and 1994 and involved 1,913 people who were hospitalized after suffering a heart attack. Nearly half (47 percent) of the study participants did not drink alcohol, 36 percent were light drinkers and 17 percent were moderate drinkers.

The researchers followed up on the study participants after approximately four years (median was 3.8 years) and tracked patient deaths through a survival census. As of January 1, 1996, 317 participants had died. Mukamal and his colleagues found that 17 percent of the non-drinkers died from cardiovascular-related causes. Among the light and moderate drinkers, there were fewer cardiovascular-related deaths, 9 percent and 7 percent respectively.

To control for differences between the three groups other than alcohol consumption, the researchers determined a person’s probability of consuming alcohol based on several demographic, behavioral and clinical characteristics. These variables included age, body-mass index, sex, previous heart attack, previous heart failure, previous angina, diabetes mellitus, hypertension, non-cardiac comorbidity, previous medication use, current and previous smoking, education, and income.

[Because the average alcohol content of a typical drink differs by beverage type (beer typically contains 13.2 grams of alcohol, wine has 10.8 grams and liquor has 15.1 grams), the researchers measured how many grams of alcohol a person consumed in an average week rather than the number of drinks. They then divided the number of grams of alcohol consumed by 15 (they defined a standard drink to be equal to 15 grams of alcohol) to determine how many servings of alcohol a person drank in an average week.]

No substantial difference was detected in the survival rate among moderate drinkers who reported predominant consumption of beer, wine or liquor, said Mukamal, who also is an instructor in medicine at Harvard Medical School. Prior studies have associated red wine consumption with a lower risk of coronary heart disease, which led some to speculate that perhaps there was a chemical in the grape -- and not the alcohol in the wine -- that provided the protective benefit.

“While the findings from this and other studies suggest that moderate alcohol drinkers have a lower risk of suffering a heart attack and of dying after a heart attack, people who have heart disease or a family history of the disease should consult their physicians about ways to reduce their risk of dying from a heart attack,” says Mukamal. “The balance of risks and benefits from alcohol will be different for every individual.”

The study’s other authors are Malcolm Maclure, Sc.D., Harvard School of Public Health, James. E. Muller, M.D., Massachusetts General Hospital, Jane B. Sherwood, R.N., Harvard School of Public Health, and Murray Mittleman, M.D, Dr.P.H., Beth Israel Deaconess Medical Center.

The study was funded by the American Heart Association, the National Institute on Alcohol Abuse and Alcoholism, and the National Heart, Lung and Blood Institute.

Beth Israel Deaconess Medical Center is a major patient care, research and teaching affiliate of Harvard Medical School and a founding member of CareGroup Healthcare System. Beth Israel Deaconess is the third largest recipient of National Institutes of Health research funding among independent U.S. teaching hospitals.