Some studies suggest alcohol lowers the risk of cardiovascular disease. But the major cause of death 'by far' for middle-aged women is cancer, not heart attack or stroke, they say.
From the massive "Million Women Study" in the U.K. comes sobering news: when it comes to a woman's risk of cancer, no amount of alcohol is safe.
Even one drink a day increases the risk of several common cancers, including breast, rectum and liver cancer.
The risk increases for every additional drink, and the trend holds regardless of the type of booze consumed.
"Even relatively low levels of drinking — drinking at levels we considered relatively safe for women — increases a woman's risk of developing cancer," says Naomi Allen, a cancer epidemiologist at the University of Oxford and lead author of the study published this week in the Journal of the National Cancer Institute.
"It's important that women are as well informed as possible about these risks, so they can take responsible action for how much alcohol they drink."
That message takes on greater urgency with researchers warning women are drinking more like men. They're drinking more often, and heavier when they do drink, according to the Centre for Addictions Research of British Columbia. The phenomenon has been attributed to rising stress levels, more professional women with high disposable incomes and booze ads specifically targeted at women that portray drinking as fashionable and glamorous.
"From a standpoint of cancer risk, the message of this report could not be clearer. There is no level of alcohol consumption that can be considered safe," researchers from the National Heart, Lung and Blood Institute in Bethesda, Md., write in an accompanying editorial.
Some studies suggest alcohol lowers the risk of cardiovascular disease. But the major cause of death "by far" for middle-aged women is cancer, not heart attack or stroke, they say.
"It might be reasonable to suspect that many women in the lay public who are asking physicians about any possible safe effects of alcohol are middle aged; for this large group, the only reasonable recommendation we can make is that there is no clear evidence that alcohol has medical benefits," the editorial says.
Until now, most of the evidence linking alcohol with cancer came from studies of heavy drinking men.
Except for breast cancer, little was known about the effect of moderate drinking — one to two drinks per day — on cancer risk in women.
The study involved a total of 1,280,296 middle-aged women who attended breast cancer screening clinics in the U.K. between 1996 and 2001. The women completed questionnaires that asked, among other things, how much wine, beer and spirits they drank on average each week.
Women in the study who drank alcohol consumed, on average one drink per day; few drank three or more drinks per day. The drinkers were likely to be younger, leaner, more affluent and to exercise more frequently than non-drinkers.
During an average seven years of followup, 68,775 women were diagnosed with invasive cancers.
Even light to moderate drinking predicted a statistically significantly increased risk of rectum, liver and breast cancer. The researchers estimate that the equivalent of a glass of wine, or half pint of beer a day increases a woman's risk of breast cancer by 12 per cent. The risk of liver cancer increases 24 per cent with each daily drink, and the risk of cancer of the rectum by 10 per cent.
Overall, "we estimate about five per cent of all cancer in women is due to moderate alcohol use," Allen says.
The Canadian Cancer Society recommends that women who choose to drink should drink less than one drink per day (pregnant women should avoid alcohol). A drink is one 350 ml (12 oz.) bottle of beer, one 145 ml (5 oz.) glass of wine and one 45 ml (1.5 oz.) shot of spirits.
Women who drank and smoked had an increased risk mouth and throat, esophagus and larynx cancer.
Alcohol drinking appeared to be associated with a reduced risk of certain other cancers, including thyroid cancer, non-Hodgkin lymphoma and kidney cancer.
But the highest excess risk was for breast cancer.
The team estimates that alcohol accounts for about 11 per cent of all breast cancers in the U.K, or 5,000 extra cases each year. Extrapolated to Canada, that would mean 2,464 extra breast cancer cases annually.
The findings held after researchers took other risk factors, such as age, smoking, the use of hormone replacement therapy or birth control pills and body mass index into account.
The strongest theory is that alcohol increases levels of circulating sex hormones in women, and high levels of sex hormones in older women may double their risk of breast cancer.
The researchers also estimated that alcohol accounts for 22 per cent of liver cancers in women, and nine per cent of rectal cancers.
Canada may not have the same kind of drinking patterns as the U.K. But experts expect the findings would be similar here.
"The message to women is really to raise awareness that it's not just heavy drinking that can increase cancer risk," says Heather Chappell, senior manager of cancer control policy at the Canadian Cancer Society.
© Copyright (c) Canwest News Service
By Sharon Kirkey
Source - http://www.vancouversun.com/health/...es+risk+cancer+women+Study/1324598/story.html