Is a Bit of Bubbly a Boon or a Bane? : Drinking: Mixed messages on the effect alcohol has on health have left the public and the scientific community a little dizzy.
Once upon a time, it seemed the only thing you needed to know about alcohol was that if you drank too much of it, you got drunk.
As long as you didn’t put a lampshade on your head and insult your boss at the office Christmas party, you probably didn’t have too much to worry about.
But as a large and contradictory body of research about the health effects of alcohol has evolved, the decision whether to quaff a brew or mix a highball has grown vastly more complicated.
Scientists have linked alcohol use to some cancers, liver disease, birth defects and cardiovascular problems. Society is also beginning to comprehend the toll exacted by drunk driving, as well as alcohol-related accidents, suicide and family dysfunction.
Paradoxically, credible research has shown moderate drinking may help prevent heart attacks, and some studies suggest that people who drink a small amount regularly live longer.
The contradictions were neatly underlined recently with the release of two studies on drinking.
In one, federal researchers found significantly higher estrogen levels in women who had the equivalent of two drinks a day. It was suggested that this might shed light on earlier studies linking alcohol use and breast cancer.
The second study--from Brigham and Women’s Hospital in Boston--reported that people who had as many as three drinks a day had higher levels of high-density lipoproteins or HDLs and 45-50% fewer heart attacks.
For women in particular, the mixed messages are troubling. One study says drinking may increase the breast cancer risk, while another says it could reduce the risk of heart attack.
So, is drinking in moderation OK or not?
Dr. Daniel Flavin, a New York psychiatrist who is the medical-scientific director for the National Council on Alcoholism and Drug Dependence, does not object to moderate alcohol use for people with no history of alcoholism, but he doesn’t favor starting to drink to combat heart disease.
“The key issue of all this is keeping perspective,” Flavin says. “Is it appropriate that some people may conclude moderate alcohol use is an appropriate prescription for health? Our feeling is, no, it’s not.”
Flavin observes that scientists can’t agree on a definition of “moderate” drinking. It may mean anywhere from one to three drinks a day in different studies.
The council recently endorsed new USDA dietary guidelines that define “moderate” as one drink a day for a woman and two for a man.
Flavin’s position is echoed by Dr. Neil Stone, a Chicago cardiologist who chairs the American Heart Assn.’s nutrition committee.
Although more than a dozen studies conducted since the 1970s show that alcohol raises levels of HDL--the so-called good cholesterol that protects against heart disease--there are better ways to improve HDL, most notably exercise, Stone says.
“As a strategy to raise HDL, it’s a poor one because of the benefit-to-risk ratio you must consider,” he says. He notes that heavy drinking can cause hypertension and has been associated with strokes.
“On the other hand,” Stone says, “none of this is to be construed to say that a person who has one drink a day and is tolerating it well should have to quit drinking.”
So there is a consensus that while people who already drink moderately may have healthier hearts, no one should start drinking for that reason.
What about alcohol and cancer?
The research is inconsistent, according to Louise Brinton, an epidemiologist who heads the Environmental Study Section at the National Cancer Institute in Bethesda, Md.
Drinking is strongly suspected of causing cancers of the mouth, throat and esophagus, especially among smokers, Brinton says. Alcohol also is associated with cancers of the rectum, stomach, liver and pancreas, she says.
The 30 or so studies conducted over the past seven or eight years showing some connection between alcohol and breast cancer have drawn the most attention, however.
Those studies generally show that women who drink moderately have about twice the risk of developing breast cancer as those who don’t, Brinton says. But the connection isn’t clear-cut. For one thing, some of these studies examine women who only have a few drinks a week, while others focus on women who have two drinks a day.
“These inconsistencies lead to questions about the biological reality of the observation,” she says.
Also, scientists have speculated that the breast cancer risk is most affected by how much alcohol a woman drinks during her late teens and 20s, a period when breast tissue is still developing, Brinton says.
Until a clear-cut mechanism explaining exactly how alcohol might cause breast cancer is established, alcohol is “one of those risk factors that we still consider in the speculative category,” she says.
For women who are confused about what to do until more is known, Brinton says, “I think as long as they maintain a low level of drinking, there’s certainly not enough evidence around to suggest it causes breast cancer.”
As someone whose job is to estimate the risk of certain diseases occurring, Brinton readily admits that she drinks on occasion.
“I try to lead a prudent lifestyle,” she says. “If I believed everything epidemiologists tell us, I wouldn’t be eating, drinking or anything.”
One of the lead researchers in the most recent breast cancer study was Marsha Reichman, a former senior staff fellow at the National Cancer Institute, who acknowledges the alcohol-breast cancer issue “is not clear-cut. I think people would be happier if it was.”
Reichman and her colleagues followed 34 women on carefully controlled diets for six months. For the first three months, one group had the equivalent of two drinks of alcohol at bedtime, while the other abstained. At the end of three months, they reversed roles.
The higher estrogen levels found in the women are significant because of many earlier studies linking estrogen and breast cancer, according to Reichman. But in those studies, the estrogen-breast cancer connection was “inconsistent,” she says.
Reichman says it may turn out that alcohol is a risk only for women who already have a genetic predisposition to cancer. It may also be that the hazard occurs only when alcohol is consumed at a particular point in a woman’s menstrual cycle, she says.
When weighing the uncertainties about whether alcohol contributes to breast cancer against the evidence that it protects against heart disease, “It’s hard to make a decision,” Reichman says.
“I’m a fairly light drinker and I occasionally have wine or beer. I probably drink less than I used to. I do think about it more.”
During Pregnancy?
. . . Definitely Maybe
How much alcohol can a woman drink during pregnancy?
* One drink a day does not harm newborns.
--British Medical Journal, July 8, 1991, Los Angeles Times
* Don’t drink once you decide you want to be pregnant.
--Dr. Timothy Peters, London’s King’s College, July 8, 1991, Los Angeles Times
* The more you drink, the greater the risk, especially during the first weeks after conception. Babies of women who drink heavily (four to six mixed drinks, beers or glasses of wine per day) are much more likely to be born with fetal alcohol syndrome. Although no one knows what level of drinking during pregnancy is safe, most physicians agree that a few drinks over the course of a pregnancy is probably no cause for alarm.
--The American College of Obstetricians and Gynecologists, Oct. 30, 1991, Los Angeles Times
* There is no known safe amount of alcohol or time period in which alcohol is safe to drink during pregnancy. An average of one to two drinks daily is linked to decreased birth weight, growth abnormalities and behavioral problems in the newborn.
--National Council on Alcoholism, May 5, 1992, Minneapolis Star Tribune
* Alcohol should be avoided before conception because by the time most women know they are pregnant, the fetus’ organs have already started to form. It should also be avoided during pregnancy. If a pregnant woman is intoxicated, it’s in the placenta.
--Dr. John Martsolf, North Dakota geneticist, Aug. 14, 1992, Chicago Tribune
* Pregnant women should avoid alcoholic beverages completely. Mothers who consume as little as two drinks a day during pregnancy are substantially more likely to have growth retarded babies, and those who drink only later in their pregnancy are more likely to have premature, low birth weight babies.
--The American Academy of Pediatrics, May 10, 1993, Reuters
