February 24, 2009

One Alcoholic Drink Per Day Increases Women's Cancer Risk

Don't women don't have enough to worry about? The economy is a mess. Global warming might leave their children with a wrecked planet. So, what now? Well, that little guilty pleasure -- a glass of wine at the end of the day -- might not to be such a good idea after all.

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

"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 might leave many women scratching their heads -- and perhaps needing a drink more than ever -- 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, say alcohol can have "beneficial" effects, allowing women up to one drink a day (men get two, of course).

Confused? It turns out the guidelines were never intended to recommend that anyone drink for their health. Yes, it's true that studies have indicated that moderate drinking might 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 should never drink -- young people, pregnant women, those prone to alcoholism -- permission to abuse alcohol. As a result, they have long tried to walk a fine line between acknowledging the possible benefits of alcohol without 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 is 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 has been gathering detailed information from 1.28 million women ages 50 to 64 since 1996. The researchers examined how much alcohol they 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 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 is due to 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 might increase the risk.

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

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 do another analysis of data from the study to try to determine whether the net risks from cancer outweigh any heart benefits. But others 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 the company you're with."

No comments: