Hot tea consumption and its interactions with alcohol and tobacco use on the risk for esophageal cancer: A population-based cohort study

Background: Although consumption of tea at high-temperatures has been suggested as a risk factor for esophageal cancer, an association has not been observed consistently, and whether any relationship is independent of alcohol and tobacco exposure has not been evaluated. Objective: To examine whether high-temperature tea drinking, along with the established risk factors of alcohol consumption and smoking, is associated with esophageal cancer risk. Design: China Kadoorie Biobank, a prospective cohort study established during 2004 to 2008. Setting: 10 areas across China. Participants: 456 155 persons aged 30 to 79 years. Those who had cancer at baseline or who reduced consumption of tea, alcohol, or tobacco before baseline were excluded. Measurements: The usual temperature at which tea was consumed, other tea consumption metrics, and lifestyle behaviors were self-reported once, at baseline. Outcome was esophageal cancer incidence up to 2015. Results: During a median follow-up of 9.2 years, 1731 incident esophageal cancer cases were documented. High-temperature tea drinking combined with either alcohol consumption or smoking was associated with a greater risk for esophageal cancer than hot tea drinking alone. Compared with participants who drank tea less than weekly and consumed fewer than 15 g of alcohol daily, those who drank burning-hot tea and 15 g or more of alcohol daily had the greatest risk for esophageal cancer (hazard ratio [HR], 5.00 [95% CI, 3.64 to 6.88]). Likewise, the HR for current smokers who drank burning-hot tea daily was 2.03 (CI, 1.55 to 2.67). Limitation: Tea consumption was self-reported once, at baseline, leading to potential nondifferential misclassification and attenuation of the association. Conclusion: Drinking tea at high temperatures is associated with an increased risk for esophageal cancer when combined with excessive alcohol or tobacco use.