title: Smoking and exposure to environmental tobacco smoke decrease some plasma antioxidants and increase gamma-tocopherol in vivo after adjustment for dietary antioxidant intakes.
abstract: BACKGROUND
  Free radicals in cigarette smoke may cause oxidative damage to macromolecules, contributing to cardiovascular diseases and cancer. Decreased plasma antioxidant concentrations may indicate cigarette smoke-related oxidative stress.
  
  
  OBJECTIVE
  We compared the effects on plasma antioxidant concentrations in cotinine-confirmed active and passive smokers with those in nonsmokers, independent of differences in dietary intakes and other covariates.
  
  
  METHODS
  Plasma samples from 83 smokers, 40 passive smokers, and 36 nonsmokers were analyzed for total ascorbic acid, alpha- and gamma-tocopherols, 5 carotenoids, retinol, and cotinine. Groups were compared by using analysis of variance with adjustment for sex, age, race, body mass index, alcohol intake, triacylglycerol concentration, fruit and vegetable intakes, and dietary antioxidants.
  
  
  RESULTS
  After adjustment for dietary antioxidant intakes and other covariates, smokers and passive smokers had significantly lower plasma beta-carotene concentrations than did nonsmokers (0.15, 0.17, and 0.24 micro mol/L, respectively) and significantly higher gamma-tocopherol concentrations (7.8, 7.8, and 6.5 micro mol/L, respectively). Smokers had significantly lower plasma ascorbic acid and beta-cryptoxanthin concentrations than did nonsmokers and passive smokers (ascorbic acid: 43.6, 54.5, and 54.6 micro mol/L, respectively; beta-cryptoxanthin: 0.12, 0.16, and 0.16 micro mol/L, respectively) and significantly lower concentrations of lutein and zeaxanthin than did nonsmokers (0.33 compared with 0.41 micro mol/L). The P values for all the differences described above were < 0.05. No significant differences in plasma concentrations of alpha-tocopherol, alpha-carotene, total carotenoids, lycopene, or retinol were observed.
  
  
  CONCLUSIONS
  These results indicate that cigarette smokers and nonsmokers exposed to cigarette smoke have a significantly lower plasma antioxidant status than do unexposed nonsmokers, independent of differences in dietary antioxidant intakes. Further research is required to explain why plasma gamma-tocopherol concentrations were significantly higher in smokers and passive smokers than in nonsmokers.
authors.affiliation: School of Public Health, University of California, Berkeley 94720-7360, USA. mdietric@uclink.berkeley.edu
authors.forename: Marion
authors.initials: M
authors.lastname: Dietrich
authors.forename: Gladys
authors.initials: G
authors.lastname: Block
authors.forename: Edward P
authors.initials: EP
authors.lastname: Norkus
authors.forename: Mark
authors.initials: M
authors.lastname: Hudes
authors.forename: Maret G
authors.initials: MG
authors.lastname: Traber
authors.forename: Carroll E
authors.initials: CE
authors.lastname: Cross
authors.forename: Lester
authors.initials: L
authors.lastname: Packer
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000097:blood; D000975:Antioxidants / Q000008:administration & dosage / Q000378:metabolism*; D015992:Body Mass Index; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000378:metabolism*; D014028:Tobacco Smoke Pollution; D014810:Vitamin E / Q000097:blood*
chemical_list: D000975:Antioxidants; D014028:Tobacco Smoke Pollution; D014810:Vitamin E