title: Dairy foods, calcium, and colorectal cancer: a pooled analysis of 10 cohort studies.
abstract: BACKGROUND
  Studies in animals have suggested that calcium may reduce the risk of colorectal cancer. However, results from epidemiologic studies of intake of calcium or dairy foods and colorectal cancer risk have been inconclusive.
  
  
  METHODS
  We pooled the primary data from 10 cohort studies in five countries that assessed usual dietary intake by using a validated food frequency questionnaire at baseline. For most studies, follow-up was extended beyond that in the original publication. The studies included 534 536 individuals, among whom 4992 incident cases of colorectal cancer were diagnosed between 6 and 16 years of follow-up. Pooled multivariable relative risks for categories of milk intake and quintiles of calcium intake and 95% confidence intervals (CIs) were calculated. All statistical tests were two-sided.
  
  
  RESULTS
  Milk intake was related to a reduced risk of colorectal cancer. Compared with the lowest category of intake (<70 g/day), relative risks of colorectal cancer for increasing categories (70-174, 175-249, and > or =250 g/day) of milk intake were 0.94 (95% CI = 0.86 to 1.02), 0.88 (95% CI = 0.81 to 0.96), and 0.85 (95% CI = 0.78 to 0.94), respectively (P(trend)<.001). Calcium intake was also inversely related to the risk of colorectal cancer. The relative risk for the highest versus the lowest quintile of intake was 0.86 (95% CI = 0.78 to 0.95; P(trend) =.02) for dietary calcium and 0.78 (95% CI = 0.69 to 0.88; P(trend)<.001) for total calcium (combining dietary and supplemental sources). These results were consistent across studies and sex. The inverse association for milk was limited to cancers of the distal colon (P(trend)<.001) and rectum (P(trend) =.02).
  
  
  CONCLUSIONS
  Higher consumption of milk and calcium is associated with a lower risk of colorectal cancer.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. eunyoung.cho@channing.harvard.edu
authors.forename: Eunyoung
authors.initials: E
authors.lastname: Cho
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Smith-Warner
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: W Lawrence
authors.initials: WL
authors.lastname: Beeson
authors.forename: Piet A
authors.initials: PA
authors.lastname: van den Brandt
authors.forename: Graham A
authors.initials: GA
authors.lastname: Colditz
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Folsom
authors.forename: Gary E
authors.initials: GE
authors.lastname: Fraser
authors.forename: Jo L
authors.initials: JL
authors.lastname: Freudenheim
authors.forename: Edward
authors.initials: E
authors.lastname: Giovannucci
authors.forename: R Alexandra
authors.initials: RA
authors.lastname: Goldbohm
authors.forename: Saxon
authors.initials: S
authors.lastname: Graham
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Miller
authors.forename: Pirjo
authors.initials: P
authors.lastname: Pietinen
authors.forename: John D
authors.initials: JD
authors.lastname: Potter
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rohan
authors.forename: Paul
authors.initials: P
authors.lastname: Terry
authors.forename: Paolo
authors.initials: P
authors.lastname: Toniolo
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Virtanen
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Alicja
authors.initials: A
authors.lastname: Wolk
authors.forename: Kana
authors.initials: K
authors.lastname: Wu
authors.forename: Shiaw-Shyuan
authors.initials: SS
authors.lastname: Yaun
authors.forename: Anne
authors.initials: A
authors.lastname: Zeleniuch-Jacquotte
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000517:prevention & control; D000328:Adult; D000368:Aged; D000818:Animals; D002136:Calcium, Dietary / Q000008:administration & dosage*; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D003611:Dairy Products / Q000706:statistics & numerical data*; D004435:Eating; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008892:Milk; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012107:Research Design; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
chemical_list: D002136:Calcium, Dietary