Dietary Vitamin C Intake and Concentrations in the Body Fluids and Cells of Male Smokers and Nonsmokers

Abstract

Inhaled cigarette smoke releases a variety of oxidizing agents. Ascorbic acid is recognized as an important biological antioxidant. To better characterize the antioxidant protective role of ascorbic acid, a comparison of ascorbic acid concentrations in plasma, leukocytes, bronchoalveolar lavage fluid and alveolar macrophages from a homogeneous group of healthy male smokers (n = 10) and nonsmokers (n = 14) was investigated. The resulting ascorbic acid contents were (means ± SD) 91 ± 25 (n = 10) and 87 ± 25 (n = 14) µmol/L in plasma, 2.09 ± 0.62 (n = 7) and 2.12 ± 0.77 (n = 11) µmol/10⁹ cells in mononuclear leukocytes, 3.2 ± 2.2 (n = 10) and 1.7 ± 1.5 (n = 13) µmol/L in bronchoalveolar lavage fluid and 3.4 ± 2.3 (n = 8) and 1.6 ± 1.3 (n = 6) µmol/10⁹ cells in alveolar macrophages from smokers and nonsmokers, respectively. Mean daily dietary vitamin C intake was 116 ± 68 and 107 ± 59 mg/d for smokers and nonsmokers, respectively. The ascorbic acid contents of bronchoalveolar lavage [3.9 ± 1.9 µmol/L (n = 8)] and alveolar macrophages [4.1 ± 2.1 µmol/10⁹ cells (n = 6)] of smokers consuming 15 to 20 cigarettes/d were significantly higher (P < 0.05) than those of nonsmokers. The increased content of ascorbic acid in bronchoalveolar lavage and in alveolar macrophages of smokers compared with nonsmokers may reflect a defensive mechanism against free radical species derived from cigarette smoke.