Sweetened Beverage Consumption and Risk of Biliary Tract and Gallbladder Cancer in a Prospective Study

Background: Sugar-sweetened beverage consumption raises blood glucose concentration and has been positively associated with weight gain and type 2 diabetes, all of which have been implicated in the development of biliary tract cancer (BTC). This study examined the hypothesis that sweetened beverage consumption is positively associated with risk of BTC in a prospective study. Methods: The study population comprised 70 832 Swedish adults (55.9% men, age 45-83 years) from the Swedish Mammography Cohort and Cohort of Swedish Men who were free of cancer and diabetes and completed a food frequency questionnaire at baseline. Incident BTC case patients were ascertained through linkage with the Swedish Cancer Register. Cox proportional hazards regression model was used to analyze the data. All statistical tests were two-sided. Results: During a mean follow-up of 13.4 years, 127 extrahepatic BTC case patients (including 71 gallbladder cancers) and 21 intrahepatic BTC case patientswere ascertained. After adjustment for other risk factors, women and men in the highest category of combined sugar-sweetened and artificially sweetened beverage consumption had a statistically significantly increased risk of extrahepatic BTC and gallbladder cancer. The multivariable hazard ratios for two or more servings per day (200 mL/serving) of sweetened beverages compared with no consumption were 1.79 (95% confidence interval [CI] = 1.02 to 3.13) for extrahepatic BTC and 2.24 (95% CI = 1.02 to 4.89) for gallbladder cancer. The corresponding hazard ratio for intrahepatic BTC was 1.69 (95% CI = 0.41 to 7.03). Conclusions: These findings support the hypothesis that high consumption of sweetened beverages may increase the risk of BTC, particularly gallbladder cancer.