Tea consumption and the risks of all-cause, cardiovascular disease, and cancer mortality: a meta-analysis of 38 prospective cohort data sets.

Abstract

Tea consumption has been considered beneficial to human health because tea contains phytochemicals such as polyphenols and theaflavins. We conducted a systematic review and meta-analysis on the association between tea consumption and mortality from all causes, cardiovascular disease (CVD), and cancer to provide a quantitative assessment of current evidence. The PubMed, Web of Science, and Scopus databases were searched through April 2024 to identify eligible studies. Random effects models were used to combine study-specific effect estimates (ESs). A total of 38 prospective cohort data sets (from 27 papers) with 1,956,549 participants were included in this meta-analysis. The pooled ESs of the highest versus lowest categories of tea consumption were 0.90 (95% CI, 0.86-0.95) for all-cause mortality, 0.86 (95% CI, 0.79-0.94) for CVD mortality, and 0.90 (95% CI, 0.78-1.03) for cancer mortality. In the dose-response analysis, a nonlinear association was observed. The greatest risk reductions were observed for the consumption of 2 cups/day for all-cause mortality (ES, 0.91; 95% CI, 0.88-0.94) and 1.5 cups/day for cancer mortality (ES, 0.92; 95% CI, 0.89-0.96), whereas additional consumption did not show a further reduction in the risk of death. A plateau was observed for CVD mortality at moderate consumption levels (1.5-3 cups/day), but a sustained reduction in mortality risk was observed at higher intake levels. Moderate tea consumption (e.g., 1.5-2 cups/day) was associated with lower all-cause, CVD, and cancer mortality compared to no tea consumption. Further well-designed prospective studies are needed for a definitive Conclusion.