Yong-Jian Zhu1, Ya-Cong Bo2, Xin-Xin Liu2, Chun-Guang Qiu3. 1. Department of Cardiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China. 2. Department of Nutrition and Food Hygiene, College of Public Health, Zhengzhou University, Zhengzhou, Henan, China. 3. Department of Cardiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China. Email: qiu_contribution@163.com.
Abstract
BACKGROUND AND OBJECTIVES: Several epidemiological studies investigating the association between dietary vitamin E intake and the risk of lung cancer have demonstrated inconsistent results. Hence, a meta-analysis was conducted to summarise evidence of the association of dietary vitamin E intake with the risk of lung cancer. METHODS AND STUDY DESIGN: In this meta-analysis, a systematic literature search of PubMed and Web of Science was conducted to identify relevant studies published from 1955 to April 2015. If p<0.05 or I2 >50%, a random effect model was used to estimate overall relative risks (RRs) and 95% confidence intervals (CIs). Otherwise, a fixed effect model was applied. Publication bias was estimated using the funnel plot and Egger's test. The doseresponse relationship was assessed using the method of restricted cubic splines with 4 knots at percentiles 5, 35, 65, and 95 of the distribution. RESULTS: The pooled RR of lung cancer for the highest versus lowest categories of dietary vitamin E intake was 0.84 (95% CI=0.76-0.93). With every 2 mg/d increase in dietary vitamin E intake, the risk of lung cancer statistically decreased by 5% (RR=0.95, 95% CI =0.91-0.99, plinearity=0.0237). CONCLUSIONS: Our analysis suggests that higher dietary vitamin E intake exerts a protective effect against lung cancer.
BACKGROUND AND OBJECTIVES: Several epidemiological studies investigating the association between dietary vitamin E intake and the risk of lung cancer have demonstrated inconsistent results. Hence, a meta-analysis was conducted to summarise evidence of the association of dietary vitamin E intake with the risk of lung cancer. METHODS AND STUDY DESIGN: In this meta-analysis, a systematic literature search of PubMed and Web of Science was conducted to identify relevant studies published from 1955 to April 2015. If p<0.05 or I2 >50%, a random effect model was used to estimate overall relative risks (RRs) and 95% confidence intervals (CIs). Otherwise, a fixed effect model was applied. Publication bias was estimated using the funnel plot and Egger's test. The doseresponse relationship was assessed using the method of restricted cubic splines with 4 knots at percentiles 5, 35, 65, and 95 of the distribution. RESULTS: The pooled RR of lung cancer for the highest versus lowest categories of dietary vitamin E intake was 0.84 (95% CI=0.76-0.93). With every 2 mg/d increase in dietary vitamin E intake, the risk of lung cancer statistically decreased by 5% (RR=0.95, 95% CI =0.91-0.99, plinearity=0.0237). CONCLUSIONS: Our analysis suggests that higher dietary vitamin E intake exerts a protective effect against lung cancer.
Authors: Soumyasri Das Gupta; Misaal Patel; Joseph Wahler; Min Ji Bak; Brian Wall; Mao-Jung Lee; Yong Lin; Weichung Joe Shih; Li Cai; Chung S Yang; Nanjoo Suh Journal: Cancer Prev Res (Phila) Date: 2017-09-28