Moderate Alcohol Intake Ups Breast Cancer Risk
Drinking alcohol is a known risk factor for breast cancer. Now, a large new study suggests that drinking three to six glasses of wine per week throughout life increases a woman's risk of breast cancer by a small but significant amount.
The study is published in the November issue of The Journal of the American Medical Association.
The goal of the study was to better understand how the amount, frequency, and drinking age of alcohol intake affected breast cancer risk. Study researchers tracked approximately 105,000 women for 28 years, beginning in 1980. Throughout the study, the women were periodically asked to update their alcohol consumption patterns. Cumulative intake was calculated by averaging alcohol patterns over time.
The study saw a 15 percent increased risk of breast cancer when women drank an average of 5 to 9.9 grams of alcohol per day – equal to about 3 to 6 drinks per week – compared to women who did not drink. Risk increased more when women drank more than 30 grams of alcohol daily on average, about 2 drinks per day. Alcohol consumption both earlier in life, ages 18 to 40, and later in life, after age 40, was independently linked to increased risk of breast cancer.
Source: Chen WY, Rosner B, Hankinson SE, Colditz GA, Willett WC. "Moderate alcohol consumption during adult life, drinking patterns, and breast cancer risk." JAMA. 2011 Nov 2;306(17):1884-90.