Consumption of 3 to 6 alcoholic drinks per week is associated with a small increase in the risk of breast cancer, and consumption in both earlier and later adult life is also associated with an increased risk, according to a study in the November 2 issue of JAMA.
“In many studies, higher consumption of alcohol has been associated with an increased risk of breast cancer. However, the effect of low levels of drinking as is common in the United States has not been well quantified,” according to background information in the article. “In addition, the role of drinking patterns (i.e., frequency of drinking and ‘binge’ drinking) and consumption at different times of adult life are not well understood.”
Wendy Y. Chen, M.D., M.P.H., of Brigham and Women's Hospital and Harvard Medical School, Boston, and colleagues examined the association of breast cancer with alcohol consumption during adult life, including quantity, frequency, and age at consumption. The study included 105,986 women enrolled in the Nurses' Health Study who were followed up from 1980 until 2008 with an early adult alcohol assessment and 8 updated alcohol assessments. The primary outcome the researchers measured was the risk of developing invasive breast cancer.
During the follow-up period, there were 7,690 cases of invasive breast cancer diagnosed among the study participants. Analyses of data indicated that a low level of alcohol consumption (5.0 to 9.9 grams per day, equivalent to 3-6 glasses of wine per week) was modestly but statistically significantly associated with a 15 percent increased risk of breast cancer. In addition, women who consumed at least 30 grams of alcohol daily on average (at least 2 drinks per day) had a 51 percent increased risk of breast cancer compared with women who never consumed alcohol. > > > > Read More
