Abstract 1752: Dietary fat intake during adolescence and breast density among young women

Abstract

Abstract BACKGROUND: Lack of association between fat intake and breast cancer risk in cohort studies might be attributed to disregard of temporal effects during adolescence when breasts develop and are particularly sensitive to stimuli. We prospectively examined associations between adolescent fat intakes and breast density. METHOD: Among 177 women who participated in the Dietary Intervention Study in Children, dietary intakes at ages 10-18 were assessed on five occasions by 24-hour recalls and averaged. We calculated geometric mean and 95% confidence intervals for MRI-measured breast density at ages 25-29 across quartiles of fat intake using linear mixed-effect regression. RESULTS: Comparing women in the extreme quartiles of adolescent fat intakes, percent dense breast volume (%DBV) was positively associated with saturated fat (mean = 16.4% vs. 21.5%; Ptrend<0.001). Conversely,%DBV was inversely associated with monounsaturated fat (25.0% vs. 15.8%; Ptrend<0.001) and the ratio of polyunsaturated fat to saturated fat (P/S ratio; 19.1% vs. 14.3%; Ptrend:<0.001). When examining intake by pubertal stages,%DBV was inversely associated with intake of polyunsaturated fat (20.8% vs. 16.4%; Ptrend = 0.04), long-chain omega-3 fat (17.8% vs. 15.8%; Ptrend<0.001), and P/S ratio (22.5% vs. 16.1%; Ptrend<0.001) before menarche, but not after. These associations observed with%DBV were consistently observed with absolute dense breast volume but not with absolute non-dense breast volume. CONCLUSIONS: In our study, adolescent intakes of higher saturated fat and lower mono- and polyunsaturated fat are associated with higher breast density measured approximately 15 years later. IMPACT: The fat subtype composition in adolescent diet may be important in early breast cancer prevention. Citation Format: Seungyoun Jung. Dietary fat intake during adolescence and breast density among young women. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1752.