Seemingly innocent sips of wine on the daily may be increasing a woman’s risk of developing breast cancer, reports a new study from the American Institute for Cancer Research and the World Cancer Research Fund.
This year, an estimated 246,660 women in the US will be diagnosed with breast cancer, which currently ranks as one of the most common causes of cancer deaths in American women. The disease risk is influenced by environmental factors, including modifiable behaviors such as alcohol consumption. Studies have established a positive correlation between the two factors, showing that increased alcohol intake leads to increased risks for breast cancers. Alcohol consumption is also associated with increased recurrence in postmenopausal women and those with early stage breast cancer.
But the exact magnitude of the risk posed by daily drinking and breast cancer development was not studied, until now. The current study analyzed data from 119 studies, which combined to a total of 12 million women and over 260,000 breast cancer cases. They found that consuming just 10 grams of alcohol a day - the equivalent to a small glass of wine or an 8-ounce beer - increases the risk of breast cancer by 5 percent and 9 percent in premenopausal and postmenopausal women, respectively.
"I was most surprised by the alcohol result, that risk increases at just one drink a day, on average," said Dr. Anne McTiernan, the study’s lead author. "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."
What’s the mechanism behind alcohol and breast cancer? Researchers suspect pathways in alcohol metabolism could induce DNA damages, leading to cancer. "In exposed tissues, alcohol is converted into acetaldehyde, a chemical that can cause mutations in DNA, which can potentially lead to cancer," said Chin-Yo Lin, a cancer researcher at the University of Houston’s Center for Nuclear Receptors and Signaling, who was not involved with the study.
Alcohol is also implicated in dysregulating the female sex hormone estrogen. "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," said Lin. "A number of studies have shown that alcohol can enhance the actions of estrogen in breast cancer cells."
And just last year, Lin and his team showed that alcohol alters the expression of the cancer-driving gene BRAF, which then increases the overall risks for breast cancer in women.
Taken together, it seems alcohol is no friend to health. But things are rarely so straightforward, and alcohol’s story isn’t all bad. For instance, light consumption of the spirit could protect against heart disease. Furthermore, breast cancer development is quite complex and governed by many other immutable factors, like age, sex, and genetic predisposition. Still, the new study results underscore just how easily lifestyle choices can directly influence our health risks, and the awareness of which could promote healthier behavioral changes.
Additional source: CNN
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