title: Dietary intake of B vitamins and methionine and risk of lung cancer.
abstract: OBJECTIVE
  B vitamins and related enzymes involved in one-carbon metabolism are necessary for DNA replication, DNA repair and regulation of gene expression. Disruption of one-carbon mechanism may affect cancer risk. We investigated prospectively the relationship between dietary intakes of methionine, B vitamins associated with one-carbon metabolism and risk of lung cancer.
  
  
  METHODS
  The Melbourne Collaborative Cohort Study recruited 41,514 men and women aged 40-69 years between 1990 and 1994. During follow-up of 14,595 men and 22,451 women for an average of 15 years, we ascertained 348 incident lung cancers. Dietary intake of B vitamins and methionine was estimated from a 121-item food frequency questionnaire. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression.
  
  
  RESULTS
  In current smokers, dietary intake of riboflavin was inversely associated with lung cancer risk (HR=0.53; 95% CI: 0.29-0.94, fifth versus first quintile; P-linear trend=0.01). No associations were found for former or never smokers or for dietary intake of any of the other B vitamins or methionine.
  
  
  CONCLUSIONS
  Overall, we found little evidence of an association between B vitamins or methionine and lung cancer risk. The weak inverse association between riboflavin and lung cancer risk in current smokers needs further investigation.
authors: Cancer Epidemiology Centre, Cancer Council Victoria, Carlton South, Victoria, Australia. julie.bassett@cancervic.org.au
authors: J K
authors: JK
authors: Bassett
authors: A M
authors: AM
authors: Hodge
authors: D R
authors: DR
authors: English
authors: L
authors: L
authors: Baglietto
authors: J L
authors: JL
authors: Hopper
authors: G G
authors: GG
authors: Giles
authors: G
authors: G
authors: Severi
mesh_terms: D000328:Adult; D001315:Australia; D002244:Carbon / Q000378:metabolism; D015331:Cohort Studies; D004247:DNA / Q000378:metabolism; D004032:Diet; D004034:Diet Surveys; D002149:Energy Intake; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D008297:Male; D008715:Methionine / Q000008:administration & dosage* / Q000494:pharmacology; D008875:Middle Aged; D016016:Proportional Hazards Models; D012256:Riboflavin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D012307:Risk Factors; D012907:Smoking / Q000378:metabolism*; D011795:Surveys and Questionnaires; D014803:Vitamin B Complex / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D014803:Vitamin B Complex; D002244:Carbon; D004247:DNA; D008715:Methionine; D012256:Riboflavin