title: Drinking water and dietary sources of nitrate and nitrite and risk of glioma.
abstract: OBJECTIVE
  Dietary nitrite has been associated with increased glioma risk; however, drinking water nitrate has not been extensively evaluated.
  
  
  METHODS
  We conducted a population-based case-control study of adult glioma in Nebraska. Water utility nitrate measurements were linked to residential water source histories. We computed average nitrate exposure over a 20-year period. A food frequency questionnaire was used to assess dietary nitrate and nitrite.
  
  
  RESULTS
  Increasing quartiles of the average nitrate level in drinking water were not significantly associated with risk (adjusted odd ratios: 1.4, 1.2, 1.3). Risk was similar among those with both higher and lower intakes of vitamin C, an inhibitor of N-nitroso compound formation. Dietary nitrite intake was not associated with risk.
  
  
  CONCLUSIONS
  Our study does not support a role for drinking water and dietary sources of nitrate and nitrite in risk of adult glioma.
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, DHHS, Bethesda, Maryland Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland 20892-7240, USA. wardm@mail.nih.gov
authors.forename: Mary H
authors.initials: MH
authors.lastname: Ward
authors.forename: Ellen F
authors.initials: EF
authors.lastname: Heineman
authors.forename: Rodney D
authors.initials: RD
authors.lastname: McComb
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Weisenburger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000209:etiology*; D016022:Case-Control Studies; D004032:Diet; D004326:Drinking; D005260:Female; D005910:Glioma / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009329:Nebraska; D009566:Nitrates / Q000032:analysis*; D009573:Nitrites / Q000032:analysis*; D018570:Risk Assessment; D011795:Surveys and Questionnaires; D014881:Water Supply
chemical_list: D009566:Nitrates; D009573:Nitrites