title: Association between magnesium intake and risk of colorectal cancer among postmenopausal women.
abstract: OBJECTIVE
  Data relating to magnesium intake and colorectal cancer (CRC) risk in postmenopausal women are incomplete. We investigated the association between total magnesium intake and the risk of CRC in an ethnically diverse cohort of postmenopausal women enrolled in the Women's Health Initiative.
  
  
  METHODS
  Self-reported dietary and supplemental magnesium were combined to form total magnesium intake. Invasive incident CRC was the primary outcome. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI).
  
  
  RESULTS
  During an average follow-up of 13 years (1,832,319 person-years), of the 140,601 women included for analysis, 2,381 women were diagnosed with CRC (1,982 colon cancer and 438 rectal cancer). After adjustment for potential confounding variables, an inverse association was observed in the highest quintile of total magnesium intake compared to the lowest quintile for risk of CRC (HR 0.79, 95% CI 0.67, 0.94, p trend < 0.0001) and colon cancer (HR 0.80, 95% CI 0.66, 0.97, p trend < 0.0001). A borderline significant inverse association was detected in the highest versus the lowest quintile of total magnesium intake for rectal cancer (HR 0.76, 95% CI 0.51, 1.13, p trend < 0.001).
  
  
  CONCLUSIONS
  Findings from this study support the hypothesis that magnesium intake around 400 mg/day from both dietary and supplemental sources is associated with a lower incidence of CRC in postmenopausal women.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health - Bloomington, Indiana University, 1025 E. 7th Street 070B, Bloomington, IN, 47408, USA. amgabbar@umail.iu.edu.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Gorczyca
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health - Bloomington, Indiana University, 1025 E. 7th Street 070B, Bloomington, IN, 47408, USA.
authors.forename: Ka
authors.initials: K
authors.lastname: He
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health - Bloomington, Indiana University, 1025 E. 7th Street 070B, Bloomington, IN, 47408, USA.
authors.forename: Pencheng
authors.initials: P
authors.lastname: Xun
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, MN, USA.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.affiliation: Department of Kinesiology, School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: Janet P
authors.initials: JP
authors.lastname: Wallace
authors.affiliation: State University of New York at Stony Brook, Stony Brook, NY, USA.
authors.forename: Dorothy
authors.initials: D
authors.lastname: Lane
authors.affiliation: University of Arizona Cancer Center, Tuscon, AZ, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Thomson
authors.affiliation: Albert Einstein College of Medicine, Bronx, NY, USA.
authors.forename: Gloria Y F
authors.initials: GY
authors.lastname: Ho
authors.affiliation: Division of Preventive Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Shikany
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health - Bloomington, Indiana University, 1025 E. 7th Street 070B, Bloomington, IN, 47408, USA.
authors.forename: Juhua
authors.initials: J
authors.lastname: Luo
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000453:epidemiology*; D015179:Colorectal Neoplasms / Q000453:epidemiology; D004032:Diet; D005260:Female; D006801:Humans; D015994:Incidence; D008274:Magnesium / Q000008:administration & dosage*; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D057566:Self Report
chemical_list: D008274:Magnesium
keywords: Colon cancer; Colorectal cancer; Magnesium; Postmenopausal; Rectal cancer