title: Coffee consumption and risk of cancers: a meta-analysis of cohort studies.
abstract: BACKGROUND
  Coffee consumption has been shown to be associated with cancer of various sites in epidemiological studies. However, there is no comprehensive overview of the substantial body of epidemiologic evidence.
  
  
  METHODS
  We searched MEDLINE, EMBASE, Science Citation Index Expanded and bibliographies of retrieved articles. Prospective cohort studies were included if they reported relative risks (RRs) and corresponding 95% confidence intervals (CIs) of various cancers with respect to frequency of coffee intake. We did random-effects meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of cancer associated with 1 cup/day increment of coffee consumption.
  
  
  RESULTS
  59 studies, consisting of 40 independent cohorts, met the inclusion criteria. Compared with individuals who did not or seldom drink coffee per day, the pooled RR of cancer was 0.87 (95% CI, 0.82-0.92) for regular coffee drinkers, 0.89 (0.84-0.93) for low to moderate coffee drinkers, and 0.82 (0.74-0.89) for high drinkers. Overall, an increase in consumption of 1 cup of coffee per day was associated with a 3% reduced risk of cancers (RR, 0.97; 95% CI, 0.96-0.98). In subgroup analyses, we noted that, coffee drinking was associated with a reduced risk of bladder, breast, buccal and pharyngeal, colorectal, endometrial, esophageal, hepatocellular, leukemic, pancreatic, and prostate cancers.
  
  
  CONCLUSIONS
  Findings from this meta-analysis suggest that coffee consumption may reduce the total cancer incidence and it also has an inverse association with some type of cancers.
authors.affiliation: Department of Gastroenterology, Huadong Hospital, Fudan University, Shanghai 200040, PR China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Yu
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Bao
authors.forename: Jian
authors.initials: J
authors.lastname: Zou
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
mesh_terms: D000465:Algorithms; D003069:Coffee / Q000502:physiology; D015331:Cohort Studies; D004327:Drinking Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors
chemical_list: D003069:Coffee