Green Tea Consumption and Risk of All-Cause Mortality: Findings from a Prospective Cohort Study

Background/Objectives: There has been a growing concern about excessive caffeine consumption among heavy green tea drinkers on health outcomes, such as cardiovascular diseases or cancer. We evaluated the association between green tea consumption and risk of all-cause mortality in Vietnam. Methods: We used data from the Hanoi Prospective Cohort Study, an ongoing study comprising 42,146 participants aged 10 or older in Northern Vietnam who have been followed up between 2007 and 2019. Green tea intake was derived from a validated semi-quantitative food frequency questionnaire. We performed a Cox proportional hazard regression model to calculate the hazard ratio (HR) and respective 95% confidence intervals (95% CIs) for the association between green tea consumption and risk of all-cause mortality, adjusted for potential confounding factor. Results: After a median follow-up of 11 years (range: 0.13–11.64 years), we identified 2494 deaths. Overall, there was an inverse association between green tea intake and risk of all-cause mortality (HRperSDincrement = 0.93; 95% CI, 0.89–0.97, Ptrend < 0.001). This pattern was more pronounced in males (HRperSDincrement = 0.93; 95% CI, 0.89–0.97, Ptrend < 0.001) but not in females (HRperSDincrement = 0.94; 95% CI, 0.86–1.02, Ptrend = 0.12; Pheterogeneity = 0.81). In stratified analysis, the inverse association pattern was seen in both younger and old age groups, in individuals with BMI < 23 kg/m2, in both ever and never smokers, among ever alcohol drinkers and never coffee drinkers, and in individuals with and without history of type 2 diabetes (Pheterogeneity = 0.31). Conclusions: Findings from the current study, the first prospective cohort study in Vietnam, suggest a protective effect of green tea consumption on risk of all-cause mortality. Further studies are warranted to validate our findings in similar population and settings.