Abstract 2827: Adolescent diet and serum hormones, breast density and bone mineral density in young adults: findings from the Dietary Intervention in Children (DISC) Follow-Up Study
Authors: Dorgan Joanne F. , Liu Lea , Klifa Catherine , Shepherd John A. , Stanczyk Frank Z. , Snetselaar Linda G. , Horn Linda Van , Stevens Victor J. , Robson Alan , Kwiterovich Peter O. , Lasser Norman L. , Himes John H. , Pettee-Gabriel Kelley , Kriska Andrea , Ruder Elizabeth H. , Fang Carolyn Y. , Barton Bruce A. 
Published: February 2011

Abstract
Background: Adolescent diet is hypothesized to influence breast cancer risk, and we previously showed that an intervention to lower fat intake during adolescence was associated with lower serum estrogens and progesterone. We have now evaluated the long-term effects of this intervention on serum hormones, breast density and bone mineral density (BMD), biomarkers that are positively related to breast cancer risk in adults. Methods: We conducted a follow-up study of 230 girls who participated in 1988-1997 in the Dietary Intervention Study in Children (DISC), in which healthy, prepubertal 8-10 year olds with elevated low-density lipoprotein cholesterol were randomly assigned to usual care or to a behavioral intervention that promoted a reduced-fat diet. Follow-up visits were conducted in 2006-2008, when participants were 25-29 years old. Serum estradiol and progesterone were measured by radioimmunoassays, breast density was measured by magnetic resonance imaging, and whole body bone mineral content (BMC) and BMD were measured by dual x-ray absorptiometry (DXA). Analyses were performed using linear mixed models. All tests of statistical significance are two-sided. Results: In analyses that did not take account of current diet at the time of the follow-up visit, the only statistically significant (p=.04) treatment group difference was higher whole body BMC in the intervention group compared to the usual care group; their mean BMCs were 2,444g (95% confidence interval (CI)=2,391-2,496g) and 2,378g (95% CI=2,325-2,431g), respectively. After adjustment for current dietary intakes of fat and fiber, intervention group participants’ mean BMD was 1.19g/cm2 (95% CI=1.17-1.21g/cm2), which was statistically significantly (p=.01) higher compared to usual care group participants mean BMD of 1.16g/cm2 (95% CI=1.14-1.18g/cm2). Furthermore, mean luteal phase serum estradiol concentrations were statistically significantly (p=.02) higher in intervention group participants compared to usual care group participants after adjustment for current diet; their mean concentrations were 142pg/mL (95% CI=115-174pg/mL) and 97pg/mL (95% CI=76-122pg/mL), respectively. Serum progesterone concentrations and breast density did not differ by treatment group in unadjusted or adjusted analyses. Conclusion: Results do not support the hypothesis that consumption of a lower fat diet during adolescence reduces later breast cancer risk via effects on serum estradiol and progesterone, breast density or BMD.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2827.