DEAR DOCTOR K:
Can you explain why “moderate” drinking is defined differently for men and women? Is it because men tend to be heavier? Or is there more to it?
Women are advised to drink less alcohol than men because they are much more vulnerable to alcohol’s harmful effects.
For example, research has found that if a woman has more than one drink a day, she increases her risk of car accidents and other traumatic injuries. Her risk of high blood pressure, stroke, suicide and breast cancer goes up. And drinking more than one drink a day also increases the risk that she will go on to abuse or become dependent on alcohol.
Women also tend to advance from their first drink to their first alcohol-related problem to the need for treatment more quickly than men.
Why are women more sensitive than men to the effects of alcohol? There are two main biological explanations. The first involves an enzyme called alcohol dehydrogenase (ADH). ADH breaks down alcohol, first in the stomach and then in the liver. Women have considerably less ADH in their stomach linings than men. That means that more alcohol leaves their stomach and is absorbed into their blood. As a result, one drink for a woman has about twice the effect as one for a man.
Second, pound for pound, a woman’s body contains less water and more fatty tissue than a man’s. Water dilutes alcohol in the blood; fat retains it. So alcohol remains at higher concentrations for longer periods of time in a woman’s body. This exposes her brain and other organs to more alcohol.
Together, the increased absorption of alcohol into the blood plus lower total body water explains why women may become intoxicated more easily than men. These factors also suggest why women are more likely to suffer adverse consequences after drinking less and for fewer years than men.
Most health professionals recommend no more than one drink a day for women and no more than two drinks per day for men. One standard drink is defined as 12 ounces of beer, 5 ounces of wine or 1.5 ounces of hard liquor.
For pregnant women, as a report recently released by the American Academy of Pediatrics confirmed, no amount of alcohol is safe.
Although it is generally true that women tolerate alcohol less well than men, I can say from my own experience that there are plenty of exceptions to this “rule.” I’ve known women who could drink most men under the table. My guess is that they inherited an unusually efficient ADH enzyme. As a result, they rapidly break down alcohol in their stomach, and less alcohol gets into the blood. With less alcohol in the blood, there’s less that travels to the brain.
And I’ve known some men who get pretty silly after the first few sips. Although in several cases, it would be more accurate to say they get sillier than usual.