Yong L C, Brown C C, Schatzkin A, Dresser C M, Slesinski M J, Cox C S, Taylor P R
Division of Cancer Prevention and Control, National Cancer Institute, Bethesda, MD, USA.
Am J Epidemiol. 1997 Aug 1;146(3):231-43. doi: 10.1093/oxfordjournals.aje.a009258.
The relation between the dietary intake of vitamins E, C, and A (estimated by a 24-hour recall) and lung cancer incidence was examined in the First National Health and Nutrition Examination Survey Epidemiologic Followup Study cohort of 3,968 men and 6,100 women, aged 25-74 years. During a median follow-up period of 19 years (from 1971-1975 to 1992), 248 persons developed lung cancer. Adjusted for potential confounders using Cox proportional hazards regression methods with age as the underlying time variable, the relative risk of lung cancer for subjects in the highest quartile of vitamin C intake compared with those in the lowest quartile was 0.66 (95% confidence interval (CI) 0.45-0.96). For vitamin A intake, a protective effect was observed only for its fruit and vegetable component (carotenoids) among current smokers (relative risk = 0.49, 95% CI 0.29-0.84), but this was modified by the intensity of smoking (a statistically significant effect (relative risk = 0.33, 95% CI 0.13-0.84) was observed only for those in the lowest tertile of pack-years of smoking). The vitamin E intake-lung cancer relation was modified by the intensity of smoking with a significant protective effect confined to current smokers in the lowest tertile of pack-years of smoking (relative risk = 0.36, 95% CI 0.16-0.83). Overall, there was no additional protective effect of supplements of vitamins E, C, and A beyond that provided through dietary intake. When vitamin E, vitamin C, and carotenoid intakes were examined in combination, a strong protective effect was observed for those in the highest compared with those in the lowest quartile of all three intakes (relative risk = 0.32, 95% CI 0.14-0.74). These data provide support for a protective role of dietary vitamins E and C and of carotenoids against lung cancer risk but with a modification in effects by the intensity of cigarette exposure. While smoking avoidance is the most important behavior to reduce lung cancer risk, the daily consumption of a variety of fruits and vegetables that provides a combination of these nutrients and other potential protective factors may offer the best dietary protection against lung cancer.
在首次全国健康与营养检查调查流行病学随访研究队列中，对3968名年龄在25 - 74岁的男性和6100名女性，研究了维生素E、C和A的膳食摄入量（通过24小时膳食回顾法估算）与肺癌发病率之间的关系。在中位随访期19年（从1971 - 1975年至1992年）内，有248人患肺癌。使用以年龄为潜在时间变量的Cox比例风险回归方法对潜在混杂因素进行校正后，维生素C摄入量处于最高四分位数的受试者与最低四分位数的受试者相比，患肺癌的相对风险为0.66（95%置信区间(CI) 0.45 - 0.96）。对于维生素A摄入量，仅在当前吸烟者中观察到其水果和蔬菜成分（类胡萝卜素）具有保护作用（相对风险 = 0.49，95% CI 0.29 - 0.84），但这种作用因吸烟强度而有所改变（仅在吸烟包年数处于最低三分位数的人群中观察到具有统计学意义的效应（相对风险 = 0.33，95% CI 0.13 - 0.84））。维生素E摄入量与肺癌的关系因吸烟强度而改变，显著的保护作用仅限于吸烟包年数处于最低三分位数的当前吸烟者（相对风险 = 0.36，95% CI 0.16 - 0.83）。总体而言，维生素E、C和A补充剂除了通过膳食摄入所提供保护作用外，没有额外的保护作用。当综合考察维生素E、维生素C和类胡萝卜素的摄入量时，与所有三种摄入量均处于最低四分位数的人群相比，处于最高四分位数的人群具有很强的保护作用（相对风险 = 0.32，95% CI 0.14 - 0.74）。这些数据支持膳食中的维生素E、C和类胡萝卜素对肺癌风险具有保护作用，但这种作用会因香烟暴露强度而改变。虽然避免吸烟是降低肺癌风险最重要的行为，但每日食用富含这些营养素及其他潜在保护因素的各种水果和蔬菜，可能为预防肺癌提供最佳的膳食保护。
