Vitamin E includes several
tocopherol isoforms, which may reduce
lung cancer risk, but past studies evaluating the association between
vitamin E intake and
lung cancer risk were inconsistent. We prospectively investigated the associations between
tocopherol intake from diet and from supplements with
lung cancer risk among 72,829 Chinese female nonsmokers aged 40-70 years and participating in the Shanghai Women's Health Study (SWHS). Dietary and supplement
tocopherol exposure was assessed by a validated food-frequency questionnaire at baseline and reassessed for change in intake during follow-up. Cox proportional hazards models with time-dependent covariates were used to calculate multivariate-adjusted hazard ratios (HRs) and 95% confidence interval (CIs) for
lung cancer. After 12.02 years of follow-up, 481 women were diagnosed with
lung cancer. Total dietary
tocopherol was inversely associated with
lung cancer risk among women meeting dietary guidelines for adequate intake (AI) of
tocopherol (14 mg/day or more: HR: 0.78; 95% CI 0.60-0.99; compared with the category less than AI). The protective association between dietary
tocopherol intake and
lung cancer was restricted to women exposed to side-stream
smoke in the home and workplace [HR = 0.53 (0.29-0.97), p-trend = 0.04]. In contrast,
vitamin E supplement use was associated with increased
lung cancer risk (HR: 1.33; 95% CI: 1.01-1.73), more so for
lung adenocarcinoma risk (HR: 1.79; 95% CI: 1.23-2.60). In summary, dietary
tocopherol intake may reduce the risk of
lung cancer among female nonsmokers; however, supplements may increase
lung adenocarcinoma risk and requires further investigation.