The Effect of Daily Fluid Management and Beverages Consumption on the Risk of Bladder Cancer: A Meta-analysis of Observational Study

Epidemiological studies have evaluated the risk of bladder cancer (BCa) in relation to total fluid intake, as well as specific type of beverages consumption, with controversial results. The aim of this study was to further explore the potential relationship by conducting a meta-analysis. Fifty-four articles involving more than 43,000 BCa patients were included in this meta-analysis. A positive, though not statistically significant, association was found between total fluid intake and risk of BCa comparing the highest with lowest intake (SRRE: 1.16, 95%CI: 1.00–1.36). By conducting dose-response meta-analysis, we found that each 500 ml/day increase in total fluid intake was associated with 3.3% increased risk of BCa (RR: 1.03, 95%CI: 1.00–1.07). Pronounced increase in risk of BCa was detected when total fluid intake was more than 3000 ml/day. Meta-analyses of specific type of beverages showed increasing intake of coffee (RR: 1.03, 95%CI: 1.02–1.05) were risk factors for BCa. On the contrary, increasing intake of milk appeared to be a potential protective factor for BCa (RR: 0.90, 95%CI: 0.83–0.98). The risk of BCa was not significantly related to intake of water (RR: 1.01, 95%CI: 0.98–1.03), alcohol (RR: 1.01, 95%CI: 0.97–1.05), tea (RR: 1.01, 95%CI: 0.97–1.05) and soft drinks (RR: 1.04, 95%CI: 0.96–1.11).