A recent report warning heavy drinkers against taking supplements of beta-carotene prompted several queries from perplexed readers. One man asked whether having two or three drinks over a weekend constituted "heavy drinking."
Another wanted to know if half a bottle of wine a day, which he described as "light drinking" compared with his friends, was heavy drinking in my view.
The confusion is common, according to experts at the National ** Institute on Alcohol Abuse and Alcoholism. As the institute pointed out in a recent health alert: "Moderate drinking is difficult to define because it means different things to different people. The term is often confused with 'social drinking,' which refers to drinking patterns that are accepted by the society in which they occur."
If you travel in a bar-hopping crowd, you are likely to consume far more alcohol "socially" than, say, a person who drinks only on special occasions or at parties now and then. You may also drink more than someone who downs a cocktail each night before dinner and a glass of wine with the meal. And all of you may consider your drinking habits to be "moderate." But are they?
There is, in fact, a definition of moderate drinking that is generally accepted by scientists and other experts concerned with the health effects of alcohol. The definition is based on the daily amount of alcohol that can be consumed by an average healthy adult without untoward effects. According to guidelines issued by public health officials, moderate drinking means no more than two drinks a day for most men and no more than one drink a day for most women.
That does not mean that if you forgo alcohol on one or more days, you can make up for lost time the next time you drink. Having two drinks a day for seven days is not the same as downing 14 drinks over the weekend. Nor does "a drink" mean whatever amount happens to be in your glass.
A standard drink is defined as supplying half an ounce (12 grams) of absolute alcohol. That is approximately the amount found in each of the following: 12 ounces of regular lager beer (4 percent alcohol), 8 ounces of stout (6 percent), 5 ounces of French wine (10 percent), 4 ounces of American wine (12.5 percent), 3 ounces of sherry (16.5 percent), 1 1/4 ounces of 80-proof distilled spirits (what most people call "hard liquor," including brandy, cognac, liqueurs and cordials, 40 percent alcohol) or 1 ounce of 100-proof distilled spirits.
So if you really want to know whether you are drinking moderately, you must measure your drinks or consume them from a premeasured container. You might want to measure your glasses to find out how much they hold because one person's wine glass is another's water goblet.
The different definitions of moderate drinking for men and women are based on physiological differences. It is not a myth that women typically get drunk faster than men when they drink the same amount. There are several reasons for this.
First, women generally weigh less than men do, so the same amount of alcohol is concentrated in a smaller body mass.
Second, women typically have a higher percentage of body fat and less body water than men do. Since alcohol dissolves much more readily in water than in fat, the difference in body composition means that when alcohol enters a woman's body, it becomes more concentrated, and therefore has a more potent effect, than the same amount of alcohol would in a man's body.
pTC Third, there is an enzyme in the stomach that metabolizes alcohol before it gets into the bloodstream.That enzyme is about four times as active in men as in women. So even if a man and a woman weigh the same, have the same proportion of body fat and drink the same amount, more pure alcohol is likely to reach a woman's blood and brain than a man's.
It is also true that alcohol tends to have a more potent effect on older people. That is largely due to the increases in body fat that accompany aging. Thus, an elderly man is like a young woman with respect to his ability to handle alcohol. Accordingly, experts at the national institute recommend the elderly limit their alcohol intake to one drink a day.
Some people should not drink at all. Among them are women who are pregnant or trying to become pregnant. Heavy drinking during pregnancy can cause serious birth defects and mental retardation; lesser amounts of alcohol (two or three drinks a day) have been linked to diminished size, minor physical abnormalities and lower scores on intelligence tests among the resulting offspring. Since it is not possible to say how much alcohol a pregnant woman can safely consume, the general advice is not to drink at all until after the baby is born.
Other adults who should steer clear of alcohol include people with peptic ulcers and other health problems that might be aggravated by alcohol; people taking medications like sleeping pills, anti-depressant or anti-anxiety drugs or certain painkillers that are known to interact with alcohol; and people with a history of alcohol addiction or problem drinking, and perhaps even those with a family history of alcoholism.
Of course, alcohol should not be consumed by those who will soon be operating a motorized vehicle or other machinery that requires attentiveness, manual dexterity and quick reaction time.
Even in moderate amounts, alcohol may increase the risk of certain health problems. Although the evidence is controversial, there are some suggestions that moderate drinking may slightly increase the risk of developing breast cancer and colon cancer. Alcohol may also increase the risk of developing a hemorrhagic stroke, the relatively rare but most devastating type of stroke, which results from a ruptured blood vessel in the brain.
Finally, alcohol does contain calories: seven per gram, or 84 calories in "a drink," not counting the calories in the rest of the drink, such as in mixers like tonic or cola. If you have a weight problem, alcohol can add to it, especially if its disinhibiting effect prompts you to eat more than you might otherwise.
Why, you may wonder, should you drink at all? Dr. Enoch Gordis, director of the national institute, points out that "there are tradeoffs involved in each decision about drinking."
Most people drink because they like the effects of alcohol on their emotional state and sociability. Alcohol diminishes stress, anxiety and self-consciousness and induces feelings of relaxation and conviviality. Someone who has trouble becoming acquainted with strangers at a party may find it easier to converse under the influence of a drink or two.
As for health benefits, researchers at the University of Pittsburgh found that moderate drinking by postmenopausal women raises their estrogen levels, which may in turn reduce their risk of developing heart disease and osteoporosis.
And nearly a dozen major studies in several countries and among various ethnic groups have linked moderate drinking to a decreased risk of suffering a heart attack or a stroke caused by a blood clot. These cardiovascular benefits have been noted in both men and women.