Alcohol intake masked the protective effects of tea consumption against all-cause mortality and blood pressure progression: Findings from CHNS cohort, 1993–2011

Whether the protective effects of tea consumption interact with the status of alcohol consumption remains unknown. The present study aimed to investigate the relationship between tea consumption and mortality and blood pressure changes between alcohol consumers and non-consumers in a Chinese population.This study was conducted with a cohort of 6387 participants from the China Health and Nutrition Survey data between 1993 and 2011. Group-based trajectory modeling was conducted to identify distinct tea consumption trajectories. Kaplan-Meier and Cox regression methods were used to estimate the cumulative rate of all-cause mortality. Restricted cubic spline was performed to determine the nonlinear relationships between mean tea consumption and mortality. Generalized linear mixed-effects models (GLMM) were conducted to assess the blood pressure changes among tea consumption trajectories.We identified three tea consumption trajectories. After a median follow-up of 17.9 y, 580 (9.1%) participants died. The association between tea consumption and death interacted with alcohol drinking status. A lower morality risk for the high tea consumption trajectory was observed only in non-alcohol drinkers (hazard ratio, 0.56; 95% confidence interval, 0.40-0.77). The tea-mortality association was linear in current alcohol drinkers (Plinear = 0.002), demonstrating that mortality increased with increasing tea consumption. The results of GLMM showed that alcohol intake masked the protective effect against blood pressure progression.The results of this study demonstrated that individuals with a long-term high tea consumption trajectory had a lower risk for all-cause mortality and a slower blood pressure growth rate. The beneficial effects of tea consumption were attenuated by alcohol intake or even harmful to health.