DairyIntakesinOlderGirlsandRiskofBenignBreastDisease in Young Women

Previous investigations found high dairy intakes in girls associated with rapid height growth and excess weightgain,whichhadoppositerelationshipswithbenignbreastdisease(BBD)inyoungwomen.Weusedata fromthelongitudinalGrowingUpTodayStudy(GUTS)toinvestigatewhetherdairyintakes,inolderchildren/ adolescents, are associated with BBD risk in young women. GUTS includes 9,039 females, ages 9–15 years in 1996, who completed questionnaires annually through 2001, then in 2003, 2005, 2007, and 2010. Dietary food frequencies(1996–2001)obtainedmilk,yogurt,andcheeseintakes.On2005–2010surveys,7,011females(18–29 years) reported whether a health care provider ever diagnosed them with BBD (n ¼ 250) and if confirmed by breastbiopsy(n¼105).Logisticregressionmodelsestimatedassociationsbetweenprevalentbiopsy-confirmed BBD and dairy intakes, adjusted for age and energy. Multivariable-adjusted models additionally included menarche age, childhood adiposity, adolescent alcohol consumption, and pregnancy. Further analyses stratified by family history. Age-energy–adjusted models of dairy (milk, yogurt, cheese, total dairy servings, dairy protein, dairy fat) intakes at 14 yr found no significant associations with BBD risk [milk: OR, 0.90/ (serving/d); 95% confidence interval (CI), 0.76–1.05; dairy protein: OR, 0.98/(10 g/d); 95% CI, 0.82–1.17). Separate analyses of dairy intakes at 10 yr, intakes before the growth spurt, during the growth spurt, before menses-onset, and after menses-onset provided no significant associations with BBD. Multivariable adjustment,andfamilyhistorystratification,didnotaltertheabovefindings.Weconcludethatdairyintakesbyolder girlshavenostrongrelationwithBBDriskinyoungwomen.Becauseofsmallnumberofcases,itisimportantto continue follow-up and re-examine later. Cancer Epidemiol Biomarkers Prev; 22(4); 670–4. � 2013 AACR.