title: Baseline dietary glutamic acid intake and the risk of colorectal cancer: The Rotterdam study.
abstract: BACKGROUND
  Animal studies have shown that glutamine supplementation may decrease colon carcinogenesis, but any relation with glutamine or its precursors has not been studied in humans. The primary aim of this study was to assess whether dietary glutamic acid intake was associated with colorectal cancer (CRC) risk in community-dwelling adults. A secondary aim was to evaluate whether the association could be modified by the body mass index (BMI).
  
  
  METHODS
  This study was embedded in the Rotterdam study, which included a prospective cohort from 1990 onward that consisted of 5362 subjects who were 55 years old or older and were free of CRC at the baseline. Glutamic acid was calculated as a percentage of the total protein intake with a validated food frequency questionnaire at the baseline. Incident cases of CRC were pathology-based.
  
  
  RESULTS
  During follow-up, 242 subjects developed CRC. Baseline dietary glutamic acid intake was significantly associated with a lower risk of developing CRC (hazard ratio [HR] per percent increase in glutamic acid of protein, 0.78; 95% confidence interval [CI], 0.62-0.99). After stratification for BMI, the risk reduction for CRC by dietary glutamic acid was 42% for participants with a BMI ≤ 25 kg/m(2) (HR per percent increase in glutamic acid of protein, 0.58; 95% CI, 0.40-0.85), whereas no association was found in participants with a BMI > 25 kg/m(2) (HR per percent increase in glutamic acid of protein, 0.97; 95% CI, 0.73-1.31).
  
  
  CONCLUSIONS
  Our data suggest that baseline dietary glutamic acid intake is associated with a lower risk of developing CRC, but this association may be mainly present in nonoverweight subjects.
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Gilson G
authors.initials: GG
authors.lastname: Viana Veloso
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.|Department of Internal Medicine, Groene Hart Hospital, Gouda, the Netherlands.
authors.forename: Rikje
authors.initials: R
authors.lastname: Ruiter
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Catherina E
authors.initials: CE
authors.lastname: de Keyser
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.|Health Care Inspectorate, the Hague, the Netherlands.|Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Bruno C
authors.initials: BC
authors.lastname: Stricker
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.|Leiden University College, the Hague, the Netherlands.
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Kiefte-de Jong
mesh_terms: D000328:Adult; D000368:Aged; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D015992:Body Mass Index; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D019587:Dietary Supplements; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D018698:Glutamic Acid / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D040242:Risk Reduction Behavior; D057566:Self Report; D012907:Smoking / Q000009:adverse effects
chemical_list: D016588:Anticarcinogenic Agents; D018698:Glutamic Acid
keywords: colorectal cancer; epidemiology; glutamic acid; glutamine