Scientists said this week that the largest study to date provides firm evidence linking moderate alcohol consumption to a decreased risk of heart attacks.
The results of the research should "put to rest some of the debate raging over the past 20 years" about alcohol's alleged beneficial effects in preventing heart disease, said Dr. J. Michael Gaziano of Brigham and Women's Hospital in Boston.The study found that people who consumed three or more alcoholic drinks per day had about half the heart-attack rate as those who were virtual teetotalers, taking in less than one drink a month.
But Gaziano, who led the study appearing in The New England Journal of Medicine, cautioned that the results should not be interpreted to mean that alcohol is a health elixir.
"Obviously, there are serious downsides to excess drinking," he said. "Some people can be reassured that they can drink moderately, rather than abstaining. But this is a very complex issue, and we can't make any kind of global recommendation."
The study compared data on 340 heart-attack survivors and an equal number of control subjects, all of whom lived in the suburban Boston area. Slightly more than three-quarters of them were male, and those in both groups were about 58 years old, on average.
After adjusting for risk factors such as smoking, the researchers found that those who drank moderately had a lowered heart attack risk, apparently because they had higher levels of high-density lipoprotein, or HDL, the so-called "good cholesterol."
Scientists have found that HDL apparently works as a kind of vacuum cleaner for arteries, helping the body get rid of excess fatty deposits by carrying them away from the heart and to the liver, where they can be broken down.
Gaziana said researchers do not know why alcohol consumption seems to raise HDL levels, but he thinks it increases the liver's ability to produce HDL.
In an editorial accompanying the study, Drs. Gary Friedman and Arthur Klatsky of the Kaiser Permanente Medical Care Program in Oakland, Calif. , echoed Gaziano's warning that alcohol consumption can be a good-news, bad-news story.
"Risks to health must be weighed against the non-health-related benefits of alcohol," they said. "As in other areas of health care, the patient must, with our guidance, make the final decision."