When numerous studies show a link between moderate alcohol drinking and reduced risk of heart disease, it's no surprise that the findings have received wide press coverage.

But does this link mean that people who abstain from alcohol should start drinking for the sake of their heart?

Unfortunately, it's not that simple.

The fact is, the relationships between drinking and coronary heart disease (CHD) are complex, and the research needs to be put in context. We must weigh the benefits of moderate drinking against the dangers for many people, including those at risk for alcoholism.

The benefits seem to be real, according to a report on Alcohol and Coronary Heart Disease published by the National Institute on Alcohol Abuse and Alcoholism (NIAAA). Studies from at least 20 countries indicate that moderate drinkers experience a 20 to 40 percent lower risk of heart attacks and some other heart diseases when compared to non-drinkers. Also, moderate drinkers exhibit lower rates of CHD-related death than both heavy drinkers and abstainers. This extensive body of research includes long-term studies that involve large numbers of people.

The nutritional guidelines of the US Departments of Agriculture and Health and Human Services define moderate drinking as no more than one drink per day for women and no more than two drinks per day for men. One "standard drink" equals 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of distilled liquor.

Any statement about the benefits of moderate drinking calls for several important qualifications.

First, researchers don't know exactly how alcohol might prevent heart disease. Several theories exist. One is that alcohol reduces the tendency of blood to clot, enabling blood to flow freely. Another is that moderate amounts of alcohol prevent arteries from narrowing by lowering cholesterol deposits.

Also, certain forms of alcohol might offer more protection than others. Some studies report that wine (especially red wine) offers greater heart benefits than beer or liquors. If that's true, then the greatest benefits could result from a particular ingredient in wine, perhaps a non-alcoholic ingredient.

It's even possible that some factor associated with moderate drinking actually protects the heart. For example, one survey revealed that moderate drinkers exercised more than non-drinkers. Other studies found that moderate drinkers ate less fat and cholesterol than alcohol abstainers.

For these reasons, current research only demonstrates an association between moderate drinking and reduced heart disease. Researchers stop short of saying that alcohol directly causes the reduced risk.

A second qualification is that some people, especially persons with alcoholism, simply cannot drink safely in any amount -- even amounts considered "moderate.

The hazard is that the alcoholic drinker, even one who is abstinent and in recovery, may be tempted to return to 'controlled' drinking in an attempt to improve his or her health, said Dr. Robert Morse, professor emeritus of psychiatry at the Mayo Clinic in Rochester, Minn. This hazard is usually met with relapse into alcoholism.

Alcoholics who relapse into heavy drinking will increase their risk of certain heart conditions. These include hypertension, arrhythmia (irregular heart beat), and sudden cardiac death. In fact, years of heavy drinking can damage almost all of the body's organs and tissues.

Another qualification, or risk, is that alcohol's anti-clotting ability, potentially protective against heart attack, may increase the risk of hemorrhagic stroke.

These qualifications complicate the issue for people who want to modify their drinking behavior based on current research. To provide some prudent advice for these people, Dr. Enoch Gordis, director of the National Institute on Alcohol Abuse and Alcoholism, offers the following guidelines:

• People who currently abstain from alcohol should not be encouraged to drink solely for health reasons.
• People who choose to drink and who are not at risk for alcohol-related problems should not exceed the one- to two drink-per-day limit recommended by the US Dietary Guidelines.
• People who are drinking beyond the recommended limits should lower their drinking to a moderate level.

--Published April 10, 2000