Bond G G, Thompson F E, Cook R R
Nutr Cancer. 1987;9(2-3):109-21. doi: 10.1080/01635588709513918.
A nested case-control study conducted among a cohort of chemical manufacturing employees provided an opportunity to test the hypothesis that lung cancer risk is inversely related to dietary intake of vitamin A. Eligible for study were 308 former male employees who had died of lung cancer between 1940 and 1980. Two control groups, one a decedent and the other a "living" series, were individually matched to the cases one-for-one. Interviews were completed with 734 subjects or their next-of-kin and included a food frequency list. A vitamin A index was developed for each subject based on the frequency of consumption of 29 food items. After adjustment for a number of potentially confounding variables (e.g., smoking, educational level, and use of vitamin supplements), there was evidence that vitamin A intake was inversely associated with lung cancer risk. The effect was most pronounced in the comparisons with the "living" controls and appeared strongest among cigarette smokers. Subjects in the lowest tertile of vitamin A intake had approximately twice the risk of lung cancer as those in the highest. Analyses of an index of carotenoids and of individual food items suggested that plant sources of vitamin A may play a more important role in producing the effect than do animal sources.
在一组化工制造企业员工中开展的一项巢式病例对照研究，提供了一个检验肺癌风险与维生素A膳食摄入量呈负相关这一假设的机会。符合研究条件的是1940年至1980年间死于肺癌的308名前男性员工。两个对照组，一个是死者对照组，另一个是“在世”对照组，分别与病例一对一匹配。对734名受试者或其近亲进行了访谈，访谈内容包括一份食物频率清单。根据29种食物的食用频率为每个受试者制定了一个维生素A指数。在对一些潜在的混杂变量（如吸烟、教育程度和维生素补充剂的使用）进行调整后，有证据表明维生素A摄入量与肺癌风险呈负相关。这种效应在与“在世”对照组的比较中最为明显，并且在吸烟者中似乎最为强烈。维生素A摄入量处于最低三分位数的受试者患肺癌的风险约为摄入量处于最高三分位数者的两倍。对类胡萝卜素指数和单一食物的分析表明，维生素A的植物来源在产生这种效应方面可能比动物来源发挥更重要的作用。
