【单选题】

You’ve probably heard the reports that moderate drinking can actually be good for your heart.But before you stock up (囤积) on beer, wine, or liquor for "medicinal purposes", read the fine print.

Guidelines published by theDepartment of Health and Human Services define moderate drinking as no more than a drink a day for most women and no more than two drinks a day for most men.But even moderate drinking may be ill-advised as you get older.
Research shows that as you age, you absorb alcohol more readily and are more sensitive to its effects. So the number of drinks you could tolerate years ago may be too much for you now. Why First, your body’s ratio of water to fat falls as you age, so there’s less water to dilute (稀释) the alcohol. Second, you have less blood flow to the liver and less efficient liver enzyme action, so your body doesn’t metabolize (新陈代谢) alcohol as readily.
Women need to be especially careful, since most can’t tolerate as much alcohol as men can. One reason is that they are generally smaller, and smaller people have less blood volume, so a little alcohol goes a longer way. Women also produce less of the enzyme that breaks down alcohol in the stomach before it is absorbed into the bloodstream.And they have a higher proportion of body fat, which does not absorb alcohol. The resultDrink for drink, women have 750//00 more alcohol in their bloodstream than men do.
Despite the caveats (警告, 告诫), there’s no doubt that, for many people, limited amounts of alcohol can help you live longer and decrease your risk of heart disease. Those who may be at risk for heart disease or stroke and those who are diabetic appear to benefit most from moderate alcohol intake (one or two drinks per day) over the course of their lifetimes.
For example, in a University of Wisconsin study of diabetic men and women with an average age of 69, the risk of death from coronary heart disease was significantly lower among moderate drinkers compared to abstainers (戒酒者). The death rate for those who had a drink a day was less than half of that for those who didn’t drink at all.
Moderate drinking means ______.
A、not drinking alcohol too often
B、keeping drinking a certain amount of alcohol throughout your life
C、controlling the amount of alcohol you drink for one time
D、drinking a limited amount of alcohol every day and trying to cut the amount as you age