Liu Y et al. – Adolescent alcohol consumption is associated with increased risk of proliferative benign breast disease (BBD), which may not be reduced by increased folate intake during adolescence.

• The authors used data from 29117 women in the Nurses’ Health Study II who completed both adolescent alcohol consumption questions in 1989 and an adolescent diet questionnaire in 1998.
• A total of 659 women with proliferative BBD diagnosed between 1991 and 2001 were confirmed by central pathology review.
• Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals (CIs), adjusted for established risk factors of breast cancer.

• Adolescent alcohol consumption was dose-dependently associated with an increased risk of proliferative BBD (hazard ratio = 1.15 per 10 g/day consumption; 95% CI, 1.03–1.28).
• There was no significant association between adolescent folate intake and the risk of proliferative BBD.
• Stratified analyses showed that each 10-g/day alcohol intake during adolescence was associated with a 21% (95% CI, 1.01–1.45) increase in the risk of proliferative BBD among women with low folate intake during adolescence, which was not significantly different from the alcohol-associated risk among women with moderate and high folate intake during adolescence (P for interaction = 0.18).