title: Coffee consumption and prostate cancer risk and progression in the Health Professionals Follow-up Study.
abstract: BACKGROUND
  Coffee contains many biologically active compounds, including caffeine and phenolic acids, that have potent antioxidant activity and can affect glucose metabolism and sex hormone levels. Because of these biological activities, coffee may be associated with a reduced risk of prostate cancer.
  
  
  METHODS
  We conducted a prospective analysis of 47,911 men in the Health Professionals Follow-up Study who reported intake of regular and decaffeinated coffee in 1986 and every 4 years thereafter. From 1986 to 2006, 5035 patients with prostate cancer were identified, including 642 patients with lethal prostate cancers, defined as fatal or metastatic. We used Cox proportional hazards models to assess the association between coffee and prostate cancer, adjusting for potential confounding by smoking, obesity, and other variables. All P values were from two-sided tests.
  
  
  RESULTS
  The average intake of coffee in 1986 was 1.9 cups per day. Men who consumed six or more cups per day had a lower adjusted relative risk for overall prostate cancer compared with nondrinkers (RR = 0.82, 95% confidence interval [CI] = 0.68 to 0.98, P(trend) = .10). The association was stronger for lethal prostate cancer (consumers of more than six cups of coffee per day: RR = 0.40, 95% CI = 0.22 to 0.75, P(trend) = .03). Coffee consumption was not associated with the risk of nonadvanced or low-grade cancers and was only weakly inversely associated with high-grade cancer. The inverse association with lethal cancer was similar for regular and decaffeinated coffee (each one cup per day increment: RR = 0.94, 95% CI = 0.88 to 1.01, P = .08 for regular coffee and RR = 0.91, 95% CI = 0.83 to 1.00, P = .05 for decaffeinated coffee). The age-adjusted incidence rates for men who had the highest (≥6 cups per day) and lowest (no coffee) coffee consumption were 425 and 519 total prostate cancers, respectively, per 100 000 person-years and 34 and 79 lethal prostate cancers, respectively, per 100 000 person-years.
  
  
  CONCLUSIONS
  We observed a strong inverse association between coffee consumption and risk of lethal prostate cancer. The association appears to be related to non-caffeine components of coffee.
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA. kwilson@hsph.harvard.edu
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Wilson
authors.forename: Julie L
authors.initials: JL
authors.lastname: Kasperzyk
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Rider
authors.forename: Stacey
authors.initials: S
authors.lastname: Kenfield
authors.forename: Rob M
authors.initials: RM
authors.lastname: van Dam
authors.forename: Meir J
authors.initials: MJ
authors.lastname: Stampfer
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: Lorelei A
authors.initials: LA
authors.lastname: Mucci
mesh_terms: D000328:Adult; D000368:Aged; D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology; D003069:Coffee; D015986:Confounding Factors, Epidemiologic; D005500:Follow-Up Studies; D006282:Health Personnel / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control*; D018570:Risk Assessment; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chemical_list: D000697:Central Nervous System Stimulants; D003069:Coffee; D002110:Caffeine