A new prospective study has reported that girls who consume alcohol during adolescence are more likely to develop benign breast disease and that this risk increases in proportion with the amount of alcohol they consume. The study included 6,899 participants in the Growing Up Today Study, a prospective cohort of U.S. girls, aged 9 to 15 years at baseline, who are daughters of participants in the Nursesí Health Study II. Annual questionnaires were used between 1996 and 2001, followed by questionnaires in 2003, 2005, and 2007.

Participants (then aged 16 to 23 years) provided information about their consumption of alcoholic beverages during the previous year in the 2003 questionnaire. In the 2005 and 2007 surveys, a total of 6,899 women reported whether they had ever been diagnosed with benign breast disease and whether the diagnosis was confirmed by biopsy.

A total of 147 women reported having being diagnosed with benign breast disease, of whom 67 had disease confirmed by biopsy. Quantity of alcohol consumed was found to be associated with increased risk of biopsy-confirmed benign breast disease (a 50% increase in risk per drink per day), adjusted for age and body mass index. Girls who typically drank six or seven days per week had over five times the risk of biopsy-confirmed benign breast disease than those who never consumed alcohol or who drank less often than once per week. Participants who developed benign breast disease during the study period generally drank more often, drank more on each occasion, and had an average daily consumption that was two times that of those without benign breast disease. These girls also had more episodes of binge drinking. The authors conclude that higher amounts of alcohol consumed, as well as more frequent consumption of alcoholic beverages during adolescence may increase the occurrence of benign breast disease in young women. Since benign breast disease is associated with higher risk of breast cancer, advising teenagers to avoid alcoholic beverages may reduce breast cancer incidence in adulthood.