Oxidative stress in smokers supplemented with vitamin C.
The ability of vitamin C supplement to influence lipid peroxidation and pulmonary function tests in healthy smokers was investigated. In this randomized double blind controlled trail, 56 smokers (S) received either 500 mg of vitamin C (C) or placebo (P) daily for 4 weeks. All completed the trial. Both groups were comparable and the number of cigarettes smoked were C: 14.2 +/- 1.8 and P: 18.3 +/- 2.0 pack-years. Plasma vitamin C concentrations increased significantly (p < 0.005) only in the group supplemented with vitamin C. Lipid peroxidation measured by breath pentane output (BPO) (C: 7.5 +/- 1.4 vs P: 7.0 +/- 1.3 pmol.kg-1.min-1) and plasma HPLC-separated malondialdehyde (MDA) (C: 0.58 +/- 0.05 vs P: 0.47 +/- 0.05 nmol.ml-1) were not significantly different between the 2 groups at baseline and did not change after four weeks of vitamin C supplementation (BPO: C: 5.3 +/- 0.9 vs P: 5.5 +/- 0.9 pmol.kg-1.min-1; HPLC-MDA: C: 0.50 +/- 0.07 vs P: 0.42 +/- 0.07 nmol.ml-1). No changes were detected in pulmonary function tests even in heavy smokers. Therefore, 4 week supplementation with 500 mg of vitamin C did not change lipid peroxidation indices and had no effect on pulmonary function tests.
Dept. of Medicine, University of Toronto, Ontario, Canada.
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Aghdassi
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Royall
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Allard
D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004041:Dietary Fats / Q000008:administration & dosage; D019587:Dietary Supplements; D004311:Double-Blind Method; D002149:Energy Intake; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008168:Lung / Q000503:physiopathology; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress; D010919:Placebos; D012129:Respiratory Function Tests; D012907:Smoking / Q000503:physiopathology*
D004041:Dietary Fats; D010919:Placebos; D008315:Malondialdehyde; D001205:Ascorbic Acid