Association of Vitamin E Intake with Reduced Risk of Kidney Cancer: A Meta-Analysis of Observational Studies
Chongxing Shen, Ying Huang, Shanhong Yi, Zhenqiang Fang, Longkun Li
Department of Urology, Second Affiliated Hospital, Third Military Medical University, Chongqing, China (mainland)
Med Sci Monit 2015; 21:3420-3426
Several observational studies suggested that vitamin E intake is related to the risk of kidney cancer; however, the results of published studies are inconsistent.
MATERIAL AND METHODS: A meta-analysis was performed to assess the relationship between vitamin E intake and the risk of kidney cancer by searching PubMed and Medline through August 2015. We computed pooled relative risks (RR) and 95%CI of kidney cancer for the highest versus lowest level of vitamin E intake.
RESULTS: A total of 13 observational studies (7 case-control and 6 cohort) were included. The pooled RR (95%CI) of kidney cancer for the highest vs. the lowest level of vitamin E intake was 0.81 (0.69–0.94). In subgroup-analysis, this study found an inverse relationship between vitamin E intake and kidney cancer risk, which was not significantly modified by study design, study population, or sex distribution except in the cohort studies.
CONCLUSIONS: Results of the present study suggest an inverse relationship between vitamin E intake and kidney cancer risk. However, additional well designed cohort studies and randomized controlled trials that focus on the relationship between vitamin E intake and kidney cancer risk are needed.
Keywords: Adult, Diet, Kidney Neoplasms - prevention & control, Observational Studies as Topic, Randomized Controlled Trials as Topic, Risk Factors, Sex Factors, Vitamin E - metabolism