Vitamin E and smoking and the risk of lung cancer.
The hypotheses that the antioxidant vitamin E provides protection against lung cancer and that this hypothetical protection is modified by smoking status were investigated using two different study designs--a cohort study and a nested case-control study--among Finnish men aged 15 years and over. In the cohort study the association between vitamin E intake and lung cancer risk was studied among 5,254 individuals with 121 lung cancer cases that occurred during a 19-year follow-up, and in the nested case-control study the association between serum vitamin E level and lung cancer risk was studied using 144 lung cancer cases and 270 matched controls as a basis. There was a significant inverse association between vitamin E status and lung cancer occurrence among nonsmokers but not among smokers in both designs. The relative risk of lung cancer between the lowest and highest tertiles of vitamin E intake was 3.3 among nonsmokers and 0.8 among smokers. The corresponding results for serum vitamin E were 6.6 and 0.8, respectively. Nonsmokers with simultaneously low serum levels of vitamin E and other micronutrients (i.e., beta-carotene, retinol and selenium) had a 12-fold greater risk of lung cancer in comparison with men having more satisfactory levels. The corresponding number among smokers was three. The results suggest that vitamin E status is primarily associated with lung cancer risk among nonsmokers. Firm conclusions can, however, be drawn only on the basis of intervention trials.
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Unit of Cancer Epidemiology, Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002338:Carotenoids / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D012307:Risk Factors; D012643:Selenium / Q000097:blood; D012907:Smoking / Q000009:adverse effects*; D014801:Vitamin A / Q000097:blood; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood; D019207:beta Carotene
D019207:beta Carotene; D014801:Vitamin A; D014810:Vitamin E; D002338:Carotenoids; D012643:Selenium