Fluid intake and the risk of bladder cancer: results from the South and East China case-control study on bladder cancer

Although several studies have assessed the association between total fluid intake, specific drinks and bladder cancer, no firm conclusions can yet be drawn. Four hundred thirty two bladder cancer cases and 392 frequency matched hospital-based controls recruited in the South and East of China between October 2005 and June 2008 were interviewed on their intake of 6 nonalcoholic and 3 alcoholic drinks. Age, sex, smoking and hospital-adjusted odds ratios (OR) and 95 percent confidence intervals (95% CI) were calculated for all drinks and for total fluid intake using logistic regression. For 381 cases (81.9% men) and 371 controls (76.3% men), total fluid intake could be calculated. In men, an increase in total fluid intake was associated with a significantly decreased bladder cancer risk (OR 0.93, 95% CI: 0.88-0.99, per cup fluid consumed). Neither green nor black tea consumption was associated with bladder cancer. Daily consumption of milk significantly reduced the risk of bladder cancer by a half (OR 0.49, 95% CI: 0.32-0.76), which strengthens earlier suggestions that milk is probably associated with a decreased bladder cancer risk. Consumption of wine (OR 0.49, 95% CI: 0.34-0.70) and liquor/spirits (OR 0.65, 95% CI: 0.47-0.92) were associated with a significantly reduced risk. Consumption of water, fruit juice and beer appeared not associated with bladder cancer. There is no clear indication that the risks observed in this Chinese population are substantially different from those observed in Caucasian populations.