DEAR DOCTOR K: I enjoy an alcoholic beverage from time to time. Now I hear it may actually be good for my heart health. How can I enjoy regular drinking without it becoming a harmful habit?
DEAR READER: What you've heard is true. Study after study has shown that moderate alcohol consumption is associated with good health. But -- and it's an important "but" -- alcohol is healthful only if you drink moderately and don't go overboard. A little may be better than none, and also better than more.
In order to be sure you're drinking moderately, you have to know exactly what that means. Moderate drinking means one or two drinks per day for men and one drink per day for women. The limit is higher for men because they are larger than women, on average. Men also metabolize alcohol differently.
One alcoholic drink is usually defined as a beverage that contains 14 grams of alcohol. By that standard, a 12-ounce bottle of beer that's 5 percent alcohol counts as a single drink. So does a 5-ounce glass of wine that's 12 percent alcohol. Ditto for 1.5 ounces of hard liquor that's 40 percent alcohol (80 proof).
The health benefits of moderate alcohol intake are strongest for protection against heart attack and stroke. It can also help increase "good" HDL cholesterol. Moderate drinking also seems to lower your risk of developing Type 2 diabetes and having gallstones. It also appears to protect you against developing dementia in old age.
Unfortunately, the news isn't all good: Moderate drinking seems to increase the risk of colon and breast cancer. Women may be able to reduce the breast cancer risk some by increasing their intake of folate.
If you're drinking more than the recommended daily amount of alcohol, its benefits quickly vanish. Not only that, there's a long list of harmful side effects that take their place, including serious liver disease (cancer and cirrhosis), high blood pressure, certain cancers, traffic accidents and violence.
So what's considered heavy drinking? The National Institute on Alcohol Abuse and Alcoholism defines it for men as more than four drinks in a single day or more than 14 in a week. For women, it's defined as more than three drinks in a single day or more than seven in a week.
You may have heard that certain kinds of alcoholic drinks are "healthier" for you than others. In particular, you may have heard that red wine is particularly healthy. This is a controversial area. I think the current evidence does not suggest that red wine is any healthier than other types of alcoholic drink. There are health benefits from moderate alcohol intake of any type.
If you're worried that you're drifting into heavy drinking, keep track of how much you drink. If you decide you need to slow down, try to follow the guidelines above. And if you find you have trouble doing so, talk to your doctor about it.
(Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.)