Breast Cancer Risk Increases With Alcohol Consumption: Report

Breast cancer is the fifth most common cause of death from cancer in women. The risk for the cancer only grows the more someone drinks alcohol, a new report found.

The report from the World Cancer Research Fund and the American Institute for Cancer Research looked at new or updated studies that reviewed the link between alcohol consumption and pre- and postmenopausal breast cancer. The report found that an intake of ten grams of alcohol per day showed a five percent increased risk for premenopausal breast cancer.

For postmenopausal breast cancer, the link between breast cancer and alcohol was still present for ten grams of alcohol per day. Ten grams of alcohol is the equivalent of a small glass of wine, an eight ounce beer or one ounce of hard liquor, which was surprising, said Anne McTiernan, lead author of the report.

“I was most surprised by the alcohol result, that risk increases at just one drink a day, on average,” McTiernan, a cancer prevention researcher at the Fred Hutchinson Cancer Research Center, said to CNN. “The increase with one drink a day was small … but the risk goes up from there. So that’s why AICR recommends no more than one alcohol drink a day for women to reduce risk for cancer.”

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Researchers looked at 119 observational studies about breast cancer risks that included 12 million women and more than 260,000 cases of breast cancer. The premenopausal studies of alcohol and the risk for breast cancer alone included large numbers.

“The premenopausal analysis included ten large cohort studies in which over 4,000 women developed breast cancer,” McTiernan said. “The postmenopausal analysis included 22 large cohort studies in which over 35,000 women developed breast cancer.”

The relationship between breast cancer and alcohol is uncertain and complex, the report authors said. The dietary patterns of those who consume alcohol could be different from those who do not, as alcohol consumers have lower intakes of folate-rich foods, the authors said.

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Folate is involved in DNA functions that can be interrupted by breast cancer and low folate intake was significantly positively associated with a higher breast cancer risk as well, the authors said. Alcohol intake could also be associated with breast cancer risk because of how the body processes it, Chin-Yo Lin, a researcher at the University of Houston’s Center for Nuclear Receptors and Cell Signaling, told CNN.

“In exposed tissues, alcohol is converted into acetaldehyde, a chemical that can cause mutations in DNA, which can potentially lead to cancer,” said Lin, who wasn’t involved with the study. “Alcohol consumption is also associated with elevated levels of the female sex hormone estrogen. Excessive cumulative exposure to estrogen is a major risk factor in breast cancer. A number of studies have shown that alcohol can enhance the actions of estrogen in breast cancer cells.”