title: Low dietary nutrient intakes and respiratory health in adolescents.
abstract: BACKGROUND
  Epidemiologic studies have indicated that a diet rich in fruit, antioxidants, and n-3 fatty acids may contribute to optimal respiratory health. We investigated whether low dietary nutrient intakes were associated with lower pulmonary function and higher reporting of respiratory symptoms in adolescents.
  
  
  METHODS
  We examined the association of dietary factors (fruit, vegetables, vitamins C and E, beta-carotene, retinol, n-3 fatty acids) with respiratory health in a cohort of 2,112 twelfth-grade students in 13 communities in the United States and Canada during the 1998 to 1999 school year. We assessed the associations between dietary factors and pulmonary function with linear mixed models, and respiratory symptoms with logistic regression using a generalized estimating equation adjusted for individual and group-level covariates.
  
  
  RESULTS
  Low dietary fruit intake was associated with lower FEV(1) (- 1.3% of predicted; 95% confidence interval [CI], - 2.4 to - 0.2% of predicted), and increased odds of chronic bronchitic symptoms (odds ratio [OR], 1.36; 95% CI, 1.03 to 1.73) compared with higher intake. Low dietary n-3 fatty acids intake was associated with increased odds of chronic bronchitic symptoms (OR, 1.37; 95% confidence interval [CI], 1.05 to 1.81), wheeze (OR, 1.34; 95% CI, 1.06 to 1.69), and asthma (OR, 1.68; 95% CI, 1.18 to 2.39) compared with higher intake. Smokers with lower dietary vitamin C intake had higher ORs of respiratory symptoms compared with smokers who had higher intake.
  
  
  CONCLUSIONS
  Adolescents with the lowest dietary intakes of antioxidant and antiinflammatory micronutrients had lower pulmonary function and increased respiratory symptoms, especially among smokers, suggesting that adequate dietary intake may promote respiratory health and lessen the effects of oxidative stress.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA. jburns@hsph.harvard.edu
authors.forename: Jane S
authors.initials: JS
authors.lastname: Burns
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Dockery
authors.forename: Lucas M
authors.initials: LM
authors.lastname: Neas
authors.forename: Joel
authors.initials: J
authors.lastname: Schwartz
authors.forename: Brent A
authors.initials: BA
authors.lastname: Coull
authors.forename: Mark
authors.initials: M
authors.lastname: Raizenne
authors.forename: Frank E
authors.initials: FE
authors.lastname: Speizer
mesh_terms: D000293:Adolescent; D000975:Antioxidants / Q000502:physiology; D002170:Canada / Q000208:ethnology; D004034:Diet Surveys; D015525:Fatty Acids, Omega-3 / Q000502:physiology; D005260:Female; D005502:Food; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008171:Lung Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000503:physiopathology; D008297:Male; D009752:Nutritional Status / Q000502:physiology*; D012143:Respiratory Physiological Phenomena; D014481:United States / Q000208:ethnology; D014815:Vitamins / Q000502:physiology
chemical_list: D000975:Antioxidants; D015525:Fatty Acids, Omega-3; D014815:Vitamins