The Benefits and Risks of Alcohol

A recent, widely publicized study in the New England Journal of Medicine has led a lot of drinkers to congratulate themselves, and a lot of nondrinkers to wonder if they should start. "Drinking is good for your heart," the newspaper headlines announced, "and the more you drink, the better."

This was a well-designed study funded by the National Institutes of Health. It tracked the drinking habits of 38,000 men—all healthy at the beginning of the study—over 12 years. Men who drank at least three or four days a week had fewer heart attacks than those who drank less. It didn't matter what they drank—beer, wine or spirits—or whether they drank it with meals.

The positive news didn't end there. From the point of view of preventing heart attacks, drinking every day was better than drinking occasionally, and three drinks were better than one. Should you say hooray and head for the liquor store?

We don't think so. Whether, when and how much you should drink is a complex question, and the answer should be based on your current state of health, medical history, family history, age, sex and other factors. If ever there was a double-edged sword, it's alcohol. It benefits people (and society) in some ways and devastates them in others. It is associated with some 100,000 deaths a year from disease and injury—more than the number of deaths from heart disease (estimated at perhaps 80,000) that it may prevent. And alcohol-related deaths occur mostly among the young.

Before you embrace alcohol as heart medicine, here are some Q & A's to consider.

Does alcohol protect the heart? If so, how?

Dozens of studies have found that moderate or light drinkers have a lower risk of heart disease—30 to 50 percent lower—than nondrinkers. There is hardly any argument about this now. Furthermore, researchers have found that even when moderate drinkers do have a heart attack, they have a lower risk of dying than teetotalers or heavy drinkers, and older people who drink moderately have a lower risk of heart failure.

Alcohol raises blood levels of HDL ("good") cholesterol—which removes cholesterol from the bloodstream—and thus helps prevent hardening of the arteries (atherosclerosis). Alcohol also reduces the stickiness of platelets in the blood and thus helps prevent the blood clots that cause heart attacks. Consequently, some people compare alcohol to aspirin as a way to prevent clot formation or break up clots.

And, yes, both can be helpful, if taken in small doses. But unlike aspirin, alcohol is intoxicating and potentially addictive. The point is that alcohol is only one of several things that may protect your heart. You can reduce your risk of heart disease without drinking at all.

How clear is the evidence about the protective effect?

The evidence so far is very clear. Yet there has never been a large-scale, long-term, well-designed clinical trial testing the effect of alcohol. No matter how carefully conducted, nearly all the studies, including the one mentioned in the first paragraph, have been observational.

That is, they followed groups of drinkers and nondrinkers and compared their health over time—a valuable kind of research, but never definitive. Remember, when the evidence about hormone replacement therapy (HRT) and its benefits for women's hearts—evidence gleaned from observational studies—was tested in controlled clinical trials, the benefits vanished. Indeed, HRT turned out to do some harm.

It is hard to separate alcohol from all the other factors that affect heart disease risk (that is, "control" for those factors) in a study. For instance, moderate drinkers may have healthier habits to begin with—and thus be less likely to have heart disease. Similarly, women taking HRT tended to lead healthier lives and be better educated and more well-to-do, which may have accounted for their lower risk.