title: Tea and coffee intake in relation to risk of breast cancer in the Black Women's Health Study.
abstract: OBJECTIVE
  Prospective studies of tea and coffee intake and breast cancer risk have yielded inconsistent results. None of these studies has reported separately on African-American women. We prospectively examined the relation of tea and coffee consumption to risk of breast cancer among 52,062 women aged 21-69 at enrollment in 1995 in the Black Women's Health Study.
  
  
  METHODS
  Dietary intake was assessed in 1995 and 2001 using a validated food frequency questionnaire. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI), adjusted for breast cancer risk factors.
  
  
  RESULTS
  During 12 years of follow-up through 2007, there were 1,268 incident cases of breast cancer. Intakes of tea, coffee, and caffeine were not significantly associated with the risk of breast cancer overall. The IRRs for consumption of ≥4 cups/day compared with none were 1.13 (95% CI 0.78-1.63) for tea and 1.03 (95% CI 0.77-1.39) for caffeinated coffee, and the IRR for the top quintile relative to the bottom quintile of caffeine intake was 1.04 (95% CI 0.87-1.24). Consumption of tea, coffee, and caffeine was not significantly associated with breast cancer risk according to menopausal status or hormone receptor status.
  
  
  CONCLUSIONS
  Our findings suggest that intakes of tea, coffee, and caffeine are not associated with the risk of breast cancer among African-American women.
authors.affiliation: Slone Epidemiology Center at Boston University, 1010 Commonwealth Avenue, Boston, MA 02215, USA. dboggs@bu.edu
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Boggs
authors.forename: Julie R
authors.initials: JR
authors.lastname: Palmer
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: Lucile L
authors.initials: LL
authors.lastname: Adams-Campbell
authors.forename: Lynn
authors.initials: L
authors.lastname: Rosenberg
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D001943:Breast Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D002110:Caffeine / Q000009:adverse effects; D003069:Coffee / Q000009:adverse effects*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013662:Tea / Q000009:adverse effects*
chemical_list: D003069:Coffee; D013662:Tea; D002110:Caffeine