Dose-Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of prospective cohort studies
PubMed 32073596 · doi:10.1093/advances/nmaa010
What was done
A systematic review and dose-response meta-analysis of prospective cohort studies published through November 1, 2019, identified across six databases (PubMed, EMBASE, Web of Science, Cochrane Central, FSTA, and Ovid CAB). The synthesis assessed the association between daily tea intake and cardiovascular disease (CVD) events, stroke, CVD mortality, and all-cause mortality in generally healthy adults across 39 prospective cohort publications.
What was found
Linear meta-regression showed that each additional cup (236.6 mL) of daily tea intake was associated with a 4% lower risk of CVD mortality, a 2% lower risk of CVD events, a 4% lower risk of stroke, and a 1.5% lower risk of all-cause mortality. Subgroup meta-analysis in elderly individuals showed pooled adjusted RRs of 0.89 (95% CI: 0.83, 0.96; I² = 72.4%; n = 4) for CVD mortality and 0.92 (95% CI: 0.90, 0.94; I² = 0.3%; n = 3) for all-cause mortality. Studies with higher risk of bias showed larger associations.
Why it matters
This review quantifies dose-dependent inverse associations between habitual tea consumption and cardiovascular outcomes, supporting tea inclusion in healthy dietary patterns.
Limits
All included data derive from observational cohort studies rather than randomized controlled trials. Evidence strength was rated low for CVD events, stroke, and all-cause mortality, and low to moderate for CVD mortality. Substantial heterogeneity (I² = 72.4%) was present in the elderly CVD mortality analysis, and higher-risk-of-bias studies reported larger effect estimates. Total participant count was not reported in the abstract.
Cited by
- supports A meta-analysis of over 500,000 people found that regular tea drinking is associated with approximately a 13% reduction in stroke risk.