title: Coffee consumption and risk of prostate cancer: a meta-analysis of epidemiological studies.
abstract: OBJECTIVE
  To evaluate the association between coffee consumption and the risk of prostate cancer.
  
  
  METHODS
  We searched PubMed, EMBASE, and the bibliographies of relevant articles in August 2009. Two evaluators independently reviewed and selected articles based on predetermined selection criteria.
  
  
  RESULTS
  Twelve epidemiological studies (eight case-control studies and four cohort studies) were included in the final analysis. In a meta-analysis of all included studies, when compared with the lowest level of coffee consumption, the overall relative risk (RR) of prostate cancer for the highest level of coffee consumption was 1.16 (95% confidence interval [CI] 1.01-1.33). In subgroup meta-analyses by study design, there was a significant positive (harmful) association between coffee consumption and prostate cancer risk in seven case-control studies using both crude and adjusted data (RR 1.20, 95% CI 1.02-1.40; and RR 1.21, 95% CI 1.03-1.43, respectively), whereas there was no significant association in four cohort studies using crude or adjusted data (RR 0.97, 95% CI 0.68-1.38; and RR 1.06, 95% CI 0.83-1.35, respectively).
  
  
  CONCLUSIONS
  Given that a cohort study gives a higher level of evidence than a case-control study, there is no evidence to support a harmful effect of coffee consumption on prostate cancer risk. Further prospective cohort studies are required.
authors.affiliation: Family Medicine Clinic and Center for Cancer Prevention and Detection, National Cancer Center, Goyang, Korea.
authors.forename: Chang-Hae
authors.initials: CH
authors.lastname: Park
authors.forename: Seung-Kwon
authors.initials: SK
authors.lastname: Myung
authors.forename: Tae-Yeon
authors.initials: TY
authors.lastname: Kim
authors.forename: Hong Gwan
authors.initials: HG
authors.lastname: Seo
authors.forename: Young-Jee
authors.initials: YJ
authors.lastname: Jeon
authors.forename: Yeol
authors.initials: Y
authors.lastname: Kim
mesh_terms: D003069:Coffee / Q000009:adverse effects*; D004812:Epidemiologic Methods; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000209:etiology*
chemical_list: D003069:Coffee