title: Evaluation of brief dietary questions to estimate vegetable and fruit consumption - using serum carotenoids and red-cell folate.
abstract: OBJECTIVE
  To evaluate responses to self-administered brief questions regarding consumption of vegetables and fruit by comparison with blood levels of serum carotenoids and red-cell folate.
  
  
  METHODS
  A cross-sectional study in which participants reported their usual intake of fruit and vegetables in servings per day, and serum levels of five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene) and red-cell folate were measured. Serum carotenoid levels were determined by high-performance liquid chromatography, and red-cell folate by an automated immunoassay system.
  
  
  METHODS
  Between October and December 2000, a sample of 1598 adults aged 25 years and over, from six randomly selected urban centres in Queensland, Australia, were examined as part of a national study conducted to determine the prevalence of diabetes and associated cardiovascular risk factors.
  
  
  RESULTS
  Statistically significant (P<0.01) associations with vegetable and fruit intake (categorised into groups: </=1 serving, 2-3 servings and >/=4 servings per day) were observed for alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and red-cell folate. The mean level of these carotenoids and of red-cell folate increased with increasing frequency of reported servings of vegetables and fruit, both before and after adjusting for potential confounding factors. A significant association with lycopene was observed only for vegetable intake before adjusting for confounders.
  
  
  CONCLUSIONS
  These data indicate that brief questions may be a simple and valuable tool for monitoring vegetable and fruit intake in this population.
authors.affiliation: Nutrition Program, School of Population Health, University of Queensland, Brisbane, Queensland, Australia. t.coyne@sph.uq.edu.au
authors.forename: Terry
authors.initials: T
authors.lastname: Coyne
authors.forename: Torukiri I
authors.initials: TI
authors.lastname: Ibiebele
authors.forename: Sarah
authors.initials: S
authors.lastname: McNaughton
authors.forename: Ingrid H E
authors.initials: IH
authors.lastname: Rutishauser
authors.forename: Kerin
authors.initials: K
authors.lastname: O'Dea
authors.forename: Allison M
authors.initials: AM
authors.lastname: Hodge
authors.forename: Christine
authors.initials: C
authors.lastname: McClintock
authors.forename: Michael G
authors.initials: MG
authors.lastname: Findlay
authors.forename: Amanda
authors.initials: A
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002338:Carotenoids / Q000097:blood*; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D005247:Feeding Behavior; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005638:Fruit; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D014675:Vegetables
chemical_list: D015415:Biomarkers; D008055:Lipids; D002338:Carotenoids; D005492:Folic Acid