A Drink a Day Raises Women's Risk of Cancer, Study Indicates

By Rob Stein
Washington Post Staff Writer
Wednesday, February 25, 2009

For years, many women have been buoyed by the news about one of life's guilty pleasures: That nightly glass of wine may not only take the edge off a day but also improve their health. Now it turns out that sipping pinot noir might not be such a good idea after all.

A new study involving nearly 1.3 million middle-aged British women -- the largest ever to examine alcohol and cancer in women -- found that just one glass of chardonnay, a single beer or any other type of alcoholic drink per day increases the risk of a variety of cancers.

"That's the take-home message," said Naomi E. Allen of the University of Oxford, who led the study being published March 4 in the Journal of the National Cancer Institute. "If you are regularly drinking even one drink per day, that's increasing your risk for cancer."

Understandably, the study may leave many women scratching their heads, given all the talk about red wine being something akin to a fountain of youth.

"I thought drinking wine was good for you," said Mirella Romansini, 27, of Chevy Chase, outside Paul's liquor store in Northwest Washington. "Now they are saying it increases your risk for cancer? Yes, I would say I'm surprised."

Romansini is hardly alone. At least half of U.S. women drink sometimes, and even the Dietary Guidelines for Americans, the government's official bible on what we should be putting into our mouths, says alcohol can have "beneficial" effects, allowing women as much as one drink a day (men get two, of course).

Confused? It turns out the guidelines were never intended to recommend that anyone drink for his or her health. Yes, it's true that studies have indicated that moderate drinking may cut the risk of heart disease and other ailments. And researchers have identified a substance in red wine (remember resveratrol?) that could offer a host of benefits.

But officials have long worried about sending the wrong message, giving people who take extraordinary risks if they drink -- young people, pregnant women, those prone to alcoholism -- permission to abuse alcohol. As a result, officials have long tried to walk a fine line between acknowledging the possible benefits of alcohol and encouraging people to start drinking or to abuse it. The guidelines were intended to set an upper limit on what might be safe, not a recommended daily dose.

"It's a level of consumption that generally has been found in scientific studies to be associated with a relatively low risk of harms," said Robert D. Brewer of the federal Centers for Disease Control and Prevention. "But low risk does not mean no risk."

In fact, many previous studies have found that alcohol appears to increase the risk of breast cancer, and that heavy drinking could make men and women prone to other cancers as well. The new study is a large-scale attempt to explore all cancer risks posed by more typical drinking levels and a spectrum of alcoholic beverages.

Allen and her colleagues analyzed data collected by the Million Women Study, which since 1996 has been gathering detailed information from 1.28 million women ages 50 to 64. The researchers examined how much alcohol women reported consuming when they volunteered for the study and again three years later, and examined whether there was any link with the 68,775 cancers they developed over an average of the next seven years.

Even among women who consumed as little as 10 grams of alcohol a day on average -- the equivalent of about one drink -- the risk for cancer of the breast, liver and rectum was elevated, the researchers found. Among women who also smoked, the risk of mouth and throat cancer also increased.

Based on the findings, the researchers estimated that about 5 percent of all cancers diagnosed in women each year in the United States are the result of low to moderate alcohol consumption. Most are breast cancers, with drinking accounting for 11 percent of cases -- about 20,000 extra cases each year -- the researchers estimated.

In any group of 1,000 U.S. women up to age 75 who consumed an average of one drink a day, the researchers calculated, there would be 15 extra cancers; two drinks per day would result in 30 extra cancers, and so forth.

The risk appeared the same regardless of whether women drank wine, beer or any other type of alcohol. Allen noted that even less than one drink per day may increase the risk.

"There doesn't seem to be a threshold at which alcohol consumption is safe," she said.

The reason alcohol increases the risk for cancer is not entirely clear, but there are several possibilities, including that it enables carcinogens to do their damage, increases inflammation or, in the case of breast cancer, boosts estrogen levels.

Several researchers noted that the findings were essentially consistent with previous studies, and despite its size the study does have shortcomings. The researchers could not, for example, distinguish between women who drank only one or two drinks every day and those who drank seven drinks all at once. Some researchers worried the findings would unnecessarily frighten women and deprive them of the possible health benefits of an occasional drink.

"We can't use this to scare people away from alcohol," said Eric Rimm of the Harvard School of Public Health.

Allen plans to analyze the study data to try to determine whether the net risks from cancer outweigh any heart benefits. But others researchers were doubtful.

"Among women, the major cause of death by far during the middle age years is cancer," Michael S. Lauer and Paul Sorlie of the National Heart, Lung and Blood Institute noted in a editorial accompanying the study. "For this large group, the only reasonable recommendation we can make is there is no clear evidence that alcohol has medical benefits."

As it turns out, the federal government is rewriting its dietary guidelines, including the part about alcohol consumption, and will consider the new study in that process.

"No one study is ever sufficient to make a recommendation," said Linda Van Horn, a professor of preventive medicine at Northwestern University who is chairing the committee revising the guidelines. "But it will be added to the body of literature that will be reviewed."

In the meantime, several experts said women should consult with their doctors about whether they should drink.

"It really comes down to a personal decision based on their own history and risk factors," Rimm said. "But it shouldn't be based only on health. Some people drink for cultural reasons; some people drink for religious reasons. I personally think it enhances the flavor of meals, and some people think it enhances the company you're with."

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