September 5 (HealthDay News) -- Suppose you're a healthy, physically fit, nonsmoking male. Your risk of heart attack is already low. Would having a drink or two of alcohol a day provide any additional protective benefit?

A study by Harvard University researchers suggests that the answer is yes. Even among men who are models of health, moderate drinking was associated with a lower risk of heart attack. Those who had one-half to two drinks a day had the lowest heart attack risk -- 40 percent to 60 percent lower than healthy men who didn't drink. And that was true no matter whether they were drinking beer, wine or liquor.

"These results tend to refute the oft-quoted hypothesis that lower coronary heart disease seen among moderate drinkers is due to their associated healthy lifestyle habits, and not to their alcohol consumption," wrote Dr. R. Curtis Ellison, director of the Institute on Lifestyle and Health at Boston University School of Medicine, and co-author of a critique of the study.

In 2008, an estimated 770,000 people will suffer a heart attack, according to the American Heart Association (AHA).

Dozens of studies have linked moderate drinking and lower risk of heart disease. In a nod to that evidence, the AHA advises people who drink to do so in moderation -- no more than two drinks a day for men and one drink a day for women.

What's been less clear is whether people who exercise, abstain from smoking, maintain an optimal weight and adhere to an appropriate diet would see any benefit from drinking.

Using data from more than 50,000 health professionals, study author Dr. Kenneth J. Mukamal, assistant professor of medicine at Harvard Medical School, and his colleagues identified more than 8,800 men who were nonsmokers, ate a healthy diet, exercised at least 30 minutes a day and weren't overweight. Over a 16-year period, 106 of the men had heart attacks, but those who had two drinks a day had the lowest risk for heart attack, while non-drinkers had the highest risk.

Several other recent studies have added to the evidence suggesting that moderate alcohol intake complements a healthy lifestyle.

A recent British study identified moderate alcohol consumption among four healthy behaviors (including not smoking, exercising and eating five servings of fruits and vegetables a day) that added 14 years to life, compared with men and women who did not adopt these behaviors. And Danish researchers reported that both physical activity and moderate drinking have a protective effect on the heart and an additive benefit when combined as part of a healthy lifestyle.

There's one glaring problem, though. None of the studies were "randomized controlled trials" -- the gold standard of scientific research, whereby people are randomly assigned to an intervention, such as exercising or consuming alcohol.

There are lots of observational data to support moderate drinking, said Dr. Robert A. Vogel, professor of medicine and director of clinical vascular biology at the University of Maryland School of Medicine. "However, we do not consider alcohol a validly tested drug because to do that you would have to randomize people for years with alcohol or not -- and that's not a study that can be done," he said.

Vogel said he enjoys a daily glass of wine as part of a healthy lifestyle and tells patients who do the same that it's "a reasonable thing to do." Many doctors, though, tend to shy away from recommending alcohol to their patients. Instead, they have emphasized other lifestyle modifications, including diet and exercise.

"Clinicians are very resistant to taking alcohol out of the 'alcoholism' box and asking what its effects might be at more typical levels of intake," Mukamal said. "Even if clinicians don't believe there are benefits to alcohol, and I think that's a reasonable concern since we don't have randomized trails, they should at least be discussing it, but I don't think that's happening."

Ellison agrees. For middle-aged and older men and postmenopausal women who don't have ethical, religious or health reasons for avoiding alcohol (such as pregnancy or diseases), "physicians should at least inform them that the scientific data currently available strongly suggest that a small amount of alcohol on a regular basis may lower their risk of heart disease, stroke, diabetes, dementia, and even total mortality," he said.

SOURCES: Kenneth J. Mukamal, M.D., M.P.H., assistant professor of medicine, Harvard Medical School, and internist, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston; R. Curtis Ellison, M.D., professor of medicine and public health, and director, Institute on Lifestyle and Health, Boston University School of Medicine; Robert A. Vogel, M.D., professor of medicine, and director, clinical vascular biology, University of Maryland School of Medicine, Baltimore; Oct. 23, 2006, Archives of Internal Medicine; Oct, 23, 2006, news release, Beth Israel Deaconess Medical Center, Boston; Oct. 22, 2007, news release, Archives of Internal Medicine; Jan. 7, 2008, news release, PLoS Medicine; American Heart Association