Association between vitamin C intake and the risk of pancreatic cancer: a meta-analysis of observational studies

Quantification of the association between the intake of vitamin C and risk of pancreatic cancer is still conflicting. We therefore conducted a meta-analysis to assess the association between them. Pertinent studies were identified by a search of PubMed and Web of Knowledge through September of 2014. A random effects model was used to combine the data for analysis. Sensitivity analysis and publication bias were conducted. Data from 17 studies including 4827 pancreatic cancer cases were used in this meta-analysis. Pooled results suggested that highest vitamin C intake amount versus lowest amount was significantly associated with reduced the risk of pancreatic cancer [summary relative risk (RR) = 0.705, 95%CI = 0.612-0.811, I-2 = 42.3%]. The associations were also significant both in Caucasian [summary RR = 0.741, 95%CI = 0.626-0.876], Asian [summary RR = 0.455, 95%CI = 0.275-0.754] and Mixed population [summary RR = 0.677, 95%CI = 0.508-0.901]. No publication bias was found. Our analysis suggested that the higher intake of vitamin C might reduce the risk of pancreatic cancer.