Association between Type of Drinking Water and Upper Gastrointestinal Cancer Incidence in the Linxian General Population

Abstract

Abstract Background We aims to explore the association between type of drinking water and risk of upper gastrointestinal (UGI) cancer, including esophageal cancer (EC) and gastric cancer (GC) incidence in the Linxian General Population Nutrition Intervention Trial (NIT) cohort. Methods This study included healthy adults aged 40 to 69 years from the NIT cohort. All subjects were enrolled in April 1986 and followed through to March 2016. Subjects who drank tap water was treated as an exposed group whereas the remainders were considered as a comparison group. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using the Cox proportional hazard model. Results During the 30-year follow-up, we identified 5463 UGI cancer cases. After adjusting for age at baseline, gender, body mass index, smoking, and alcohol drinking, family history of UGI cancer, education level, nutrition intervention arms, and intakes of fruit and vegetable, the incidence rate of UGI cancer in participants who drank tap water was significantly lower than that in participants who did not drink tap water (HR = 0.88, 95%CI: 0.83–0.94). Comparable association was observed between tap water drinking and EC incidence (HR = 0.86, 95%CI: 0.79–0.94). For EC incidence, an interaction effect was observed for riboflavin/niacin supplements and type of drinking water (Pinteraction=0.03). No association was observed between type of drinking water and GC incidence. Conclusions Drinking tap water was associated with decreased risk of UGI cancer incidence particularly the of EC incidence. Appropriate measures should be taken to improve the quality of drinking water in high-incidence areas of EC. Trial registration The trial is registered with ClinicalTrials.gov (NCT00342654, 21/06/2006), and the trial name is Nutrition Intervention Trials in Linxian Follow-up Study.