TUESDAY, Feb. 24 (HealthDay News) - Research involving more than a million middle-age women finds that even moderate drinking raises risks for breast, liver and other cancers.

"Even relatively low levels of drinking -- on the order of one alcoholic drink per day -- increase a woman's risk of developing cancer," said lead researcher Naomi Allen, from the cancer epidemiology unit at the University of Oxford in the United Kingdom. "Because a high proportion of women drink low amounts of alcohol regularly and because most of the increased risk is for breast cancer, the risk among women associated with drinking alcohol is of particular importance."

In fact, the study found that moderate drinking accounts for 13 percent of breast, liver, rectum and upper respiratory/digestive tract cancers among women.

The association between moderate alcohol intake and breast cancer in women is well-known, the researchers point out. What's new here, they say, is the finding that even low levels of drinking can raise a woman's risk of developing cancer of the liver and rectum. For women who smoke, cancers of the mouth and throat were also linked to high alcohol consumption.

The report is published in the Feb. 24 online edition of the Journal of the National Cancer Institute.

For the study, Allen's team collected data on more than 1.2 million middle-age British women participating in the Million Women Study. The researchers used the National Health Service Central Registries to identify cancer cases among these women.

Most women in the study had about a drink a day, and a smaller percentage had three or more drinks a day, the researchers found. Over more than seven years of follow-up, 68,775 women developed cancer.

"These findings are robust, and alcohol consumption was assessed several times before women were diagnosed with cancer, making these estimates reliable," Allen said.

Overall, the risk of cancer increased as alcohol consumption increased. The type of alcohol consumed appeared to make no difference.