title: No association between coffee, tea or caffeine consumption and breast cancer risk in a prospective cohort study.
abstract: OBJECTIVE
  Numerous mechanisms for the effects of coffee, tea and caffeine on the risk of breast cancer have been suggested. Caffeine intake has already been associated with high plasma levels of female hormones, but associations have not been clearly demonstrated in epidemiological studies.
  
  
  METHODS
  We examined prospectively the association of coffee, tea and caffeine consumption with breast cancer risk in a French cohort study.
  
  
  METHODS
  Dietary information was obtained from a 208-item diet history questionnaire self-administered in 1993-1995. Multivariable Cox proportional hazards regression models were used to estimate hazards ratios and 95 % confidence intervals.
  
  
  METHODS
  The study was conducted on 67 703 women with available dietary information. During a median follow-up of 11 years, 2868 breast cancer cases were diagnosed.
  
  
  RESULTS
  Median intake was 280 ml/d (2·2 cups/d) for coffee and 214 ml/d (1·7 cups/d) for tea. Median caffeine intake was 164 mg/d. No association was found between consumption of coffee, tea or caffeine and breast cancer risk. Sub-analyses by tumour receptor status, menopausal status, type of coffee (regular or decaffeinated) and meals at which beverages were drunk led to the same conclusion.
  
  
  CONCLUSIONS
  Results from this prospective study showed no relationship between coffee, tea or caffeine intake and breast cancer risk overall or by hormone receptor status.
authors.affiliation: INSERM (Institut National de la Santé et de la Recherche Médicale), Center for Research in Epidemiology and Population Health (CESP), U1018, 114 rue Edouard Vaillant, F-94805 Villejuif, France.
authors.forename: Guy
authors.initials: G
authors.lastname: Fagherazzi
authors.forename: Marina S
authors.initials: MS
authors.lastname: Touillaud
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Boutron-Ruault
authors.forename: Françoise
authors.initials: F
authors.lastname: Clavel-Chapelon
authors.forename: Isabelle
authors.initials: I
authors.lastname: Romieu
mesh_terms: D001628:Beverages / Q000032:analysis*; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D002110:Caffeine / Q000008:administration & dosage* / Q000097:blood; D003069:Coffee / Q000737:chemistry*; D015331:Cohort Studies; D004034:Diet Surveys; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D013662:Tea / Q000737:chemistry*
chemical_list: D003069:Coffee; D013662:Tea; D002110:Caffeine