Relationship between tea consumption and pancreatic cancer risk: a meta-analysis based on prospective cohort studies and case-control studies.

The aim of this study was to evaluate the relationship between regular tea consumption and the risk of pancreatic cancer by a meta-analysis. Two investigators independently performed a computer retrieve on the electronic databases of Embase, PubMed, and Ovidsp for prospective cohort studies and case-control studies on regular tea consumption and the risk of pancreatic cancer incidence. The keywords using for search were ('Pancreas' OR 'pancreatic') AND ('neoplasms' OR 'carcinoma' OR 'cancer') AND 'tea'. Risk ratios (RRs) and 95% confidence interval (CI) were used to determine the effect of tea consumption on pancreatic cancer. A total of 14 studies were included (8078 pancreatic cancer patients, with a total of 859 783 patients) in the present meta-analysis. The pooled results of effect size indicated that tea consumption has no significant relationship with risk of pancreatic cancer (RR=0.99, 95% CI: 0.89-1.11, P=0.922). However, the subgroup analysis of different countries showed a statistical decrease in pancreatic cancer risk by high consumption of tea in a Chinese population (RR=0.76, 95% CI: 0.59-0.98, P=0.036). Similar results were found in the elderly (>60 years old) (RR=0.76, 95% CI: 0.60-0.96, P=0.023). In conclusion, the present meta-analysis of 14 studies suggests that the correlation between tea consumption and the risk of pancreatic cancer in the general population is not significant, but an increase in tea consumption can reduce the risk of pancreatic cancer disease in Chinese populations and in individuals older than 60 years of age. It is necessary to formulate more rigorous designs of regional studies to further confirm the relationship between tea consumption and pancreatic cancer.