Just when you've gotten over your New Year's Eve hangover, there might be a good reason to belly up to the bar again--with your doctor's blessing. A study published last week in The New England Journal of Medicine found that regular, moderate consumption of beer, wine and even hard liquor might actually be good for you. The 12-year study, conducted by researchers at Harvard, followed almost 40,000 men and found that those who drank a glass or two, three to seven times a week, cut their risk of a heart attack by a third.

This isn't the first time scientists have found health benefits from alcohol. Way back in 1974, Arthur Klatsky, now a senior cardiology consultant with Kaiser Permanente, stumbled across evidence that drinkers were less likely to have heart attacks. "That was before we even had a biological explanation," says Klatsky. "Since then, there have been literally dozens of studies." Many have shown the benefits of drinking wine--both red and white--partially because it's high in antioxidants called polyphenols, which cut down on a naturally produced substance that causes the arteries to harden and clog. In 1997 researchers broadened the field to include other alcoholic beverages, demonstrating that moderate drinkers had a 20 percent lower chance of death in a given year than those who didn't drink at all. That's probably because all kinds of alcohol--including those low in polyphenols--raise levels of HDL, or "good cholesterol," and lower levels of a blood-clotting protein. The most recent study, in which frequent drinkers fared better than those who rarely indulged, may owe its results to these anticoagulant effects, which are similar to the benefits of a daily dose of aspirin. The anticlotting factors in alcohol work only for a few hours, so those who imbibe more frequently may keep their blood thinner for longer.

None of this means teetotalers should suddenly pick up a glass. The explanations for alcohol's health benefits aren't conclusively proved, whereas its toxic effects are well known. Drinking--unlike other healthy habits related to diet and exercise--carries serious risks, like cirrhosis, hypertension and stroke. "Substitution of one disease for another is not a medical advance," notes the journal. (The study looked at heart attacks, but not other causes of death.)

Women should also be wary. Although they may also receive some of the benefits of alcohol, drinking brings other risks for them. The same 1997 study that highlighted the benefits of drinking carried a sour warning: the risk of dying of breast cancer was 30 percent higher among women who drank at least once a day. The results of the latest study don't apply to women, whose bodies react to alcohol differently than men's. Women generally have less of an alcohol-metabolizing stomach enzyme, a lower total body weight and a higher proportion of fatty (and alcohol-insoluble) tissue. The result? The alcohol sticks around in their blood longer. "I'm afraid the sexes are not equal in this respect," says Klatsky.

Still, heart disease is the bigger killer of both men and women. So if you think you're at risk for a heart attack and you've got a nice bottle of Cabernet (or a Bud Light) stowed away--well, here's to your health.