title: Use of glucosamine and chondroitin supplements and risk of colorectal cancer.
abstract: OBJECTIVE
  Glucosamine and chondroitin are non-vitamin, non-mineral supplements which have anti-inflammatory properties. These supplements are typically used for joint pain and osteoarthritis and are commonly taken as either glucosamine alone or glucosamine plus chondroitin. An exploratory analysis conducted within the VITamins And Lifestyle (VITAL) study observed any use of glucosamine and chondroitin to be associated with reduced risk of colorectal cancer (CRC) after 5 years of follow-up.
  
  
  METHODS
  With two additional years of follow-up, we have studied these associations in greater depth, including associations by frequency/duration of use and by formulation, and have evaluated whether observed associations are modified by factors associated with inflammation. Participants include 75,137 western Washington residents aged 50-76 who completed the mailed VITAL questionnaire between 2000 and 2002. Use of glucosamine and chondroitin was ascertained by questions about supplement use during the 10-year period prior to baseline, and participants were followed for CRC through 2008 (n = 557). Cox regression was used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs).
  
  
  RESULTS
  Persons reporting use of glucosamine + chondroitin on 4+ days/week for 3+ years had a non-statistically significant 45 % lower CRC risk than non-users (HR: 0.55; 95 % CI 0.30-1.01; p-trend: 0.16). This association varied by body mass index (p-interaction: 0.006), with inverse association observed among the overweight/obese (p-trend: 0.02), but not among the underweight/normal weight. Use of glucosamine alone was not significantly associated with CRC risk.
  
  
  CONCLUSIONS
  There is great need to identify safe and effective cancer preventive strategies, suggesting that glucosamine and chondroitin may merit further attention as a potential chemopreventive agent.
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N., Mailbox M4-B402, Seattle, WA 98109, USA. ekantor@fhcrc.org
authors.forename: E D
authors.initials: ED
authors.lastname: Kantor
authors.forename: J W
authors.initials: JW
authors.lastname: Lampe
authors.forename: U
authors.initials: U
authors.lastname: Peters
authors.forename: D D
authors.initials: DD
authors.lastname: Shen
authors.forename: T L
authors.initials: TL
authors.lastname: Vaughan
authors.forename: E
authors.initials: E
authors.lastname: White
mesh_terms: D000368:Aged; D002807:Chondroitin / Q000008:administration & dosage* / Q000097:blood; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000517:prevention & control; D019587:Dietary Supplements / Q000706:statistics & numerical data*; D005260:Female; D005944:Glucosamine / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D018426:SEER Program
chemical_list: D002807:Chondroitin; D005944:Glucosamine