title: Recent diet and breast cancer risk: the California Teachers Study (USA).
abstract: OBJECTIVE
  The impact, if any, on breast cancer risk of modifying adult dietary intake is an area of much interest. We take the opportunity to address the relationship between recent adult diet and breast cancer risk during the first two years of follow-up of the large California Teachers Study cohort.
  
  
  METHODS
  Of the 111.526 at-risk cohort members who resided in California and completed a baseline dietary assessment, 711 were diagnosed with invasive breast cancer after joining the cohort and before January 1998. Average daily nutrient intake was computed based on a food-frequency questionnaire assessing usual dietary intake and portion size during the year prior to joining the cohort. Incident breast cancers were identified through the California Cancer Registry and follow-up for death and confirmation of continued California residence utilized a variety of data sources. Cox proportional hazards models were used to calculate relative hazards.
  
  
  RESULTS
  The following components of recent dietary intake were not associated with breast cancer risk: energy, fat, fiber, antioxidant vitamins, and phytoestrogens. Only recent average alcohol consumption of 20 or more grams per day (approximately two or more glasses of wine) was associated with increased risk (RR= 1.5, 95% CI: 1.2-2.0 compared to non-drinkers; P(trend) = 0.01 across quintiles).
  
  
  CONCLUSIONS
  With the exception of alcohol consumption, this study provides no evidence that recent macro- or micronutrient composition of adult diet is likely to have a direct effect on breast cancer risk. Some reduction of alcohol consumption among those consuming more than one drink per day may be beneficial.
authors.affiliation: Northern California Cancer Center, Union City 94587, USA. phornros@nccc.org
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Horn-Ross
authors.forename: K J
authors.initials: KJ
authors.lastname: Hoggatt
authors.forename: Dee W
authors.initials: DW
authors.lastname: West
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Krone
authors.forename: Susan L
authors.initials: SL
authors.lastname: Stewart
authors.forename: Hoda
authors.initials: H
authors.lastname: Anton
authors.forename: Culver Leslie
authors.initials: CL
authors.lastname: Bernstei
authors.forename: Dennis
authors.initials: D
authors.lastname: Deapen
authors.forename: David
authors.initials: D
authors.lastname: Peel
authors.forename: Richard
authors.initials: R
authors.lastname: Pinder
authors.forename: Peggy
authors.initials: P
authors.lastname: Reynolds
authors.forename: Ronald K
authors.initials: RK
authors.lastname: Ross
authors.forename: William
authors.initials: W
authors.lastname: Wright
authors.forename: Al
authors.initials: A
authors.lastname: Ziogas
mesh_terms: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000517:prevention & control; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D004032:Diet; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009752:Nutritional Status; D012042:Registries / Q000706:statistics & numerical data*