Tribble D L, Giuliano L J, Fortmann S P
Stanford Center for Research in Disease Prevention, Stanford University Medical Center, CA.
Am J Clin Nutr. 1993 Dec;58(6):886-90. doi: 10.1093/ajcn/58.6.886.
Oxidants in cigarette smoke accelerate metabolic turnover of ascorbic acid (AA), and thereby deplete body stores of this potent antioxidant and putative anticarcinogen in active smokers. We examined plasma AA concentrations and vitamin C intakes in nonsmokers regularly exposed to environmental tobacco smoke (ie, passive smokers; n = 44), as compared with active smokers (n = 47) and nonexposed nonsmokers (n = 50), to determine whether passive smokers also exhibit altered AA nutriture suggestive of oxidant exposure. Plasma AA concentrations in passive smokers were intermediate between those of active smokers (P = 0.0001) and nonexposed nonsmokers (P = 0.01) despite similar dietary vitamin C intakes. Hypovitaminosis C (< 23 mumol/L) was observed in 24% of active smokers and 12% of passive smokers but not in nonexposed nonsmokers. Reduced plasma AA concentrations were associated with low vitamin C intakes within smoke-exposed populations only. We conclude that chronic smoke exposure, particularly in association with low vitamin C intake, may reduce AA pools in both active and passive smokers.
香烟烟雾中的氧化剂会加速抗坏血酸（AA）的代谢周转，从而耗尽活跃吸烟者体内这种强效抗氧化剂和潜在抗癌物质的储存。我们检测了经常接触环境烟草烟雾的非吸烟者（即被动吸烟者；n = 44）的血浆AA浓度和维生素C摄入量，并与活跃吸烟者（n = 47）和未接触者的非吸烟者（n = 50）进行比较，以确定被动吸烟者是否也表现出提示氧化剂暴露的AA营养状况改变。尽管膳食维生素C摄入量相似，但被动吸烟者的血浆AA浓度介于活跃吸烟者（P = 0.0001）和未接触者的非吸烟者（P = 0.01）之间。24%的活跃吸烟者和12%的被动吸烟者出现维生素C缺乏症（< 23 μmol/L），而未接触者的非吸烟者未出现。血浆AA浓度降低仅与烟雾暴露人群中低维生素C摄入量相关。我们得出结论，长期烟雾暴露，尤其是与低维生素C摄入量相关时，可能会减少活跃吸烟者和被动吸烟者体内的AA储备。
