Background and aims: Conflicting evidence exists regarding the association between green tea consumption and the risk of coronary heart disease (CHD). We performed a meta-analysis to determine whether an association exists between them in cohort studies.
Methods and results: We searched the PubMed and EMBASE databases for studies conducted until September 2022. Prospective cohort studies that provided relative risk (RR) estimates with 95% confidence intervals (CIs) for the association were included. Study-specific risk estimates were combined using a random-effects model. A total of seven studies, with 9211 CHD cases among 772,922 participants, were included. We observed a nonlinear association between green tea consumption and the risk of CHD (P for nonlinearity = 0.0009). Compared with nonconsumers, the RRs (95% CI) of CHD across levels of green tea consumption were 0.89 (0.83, 0.96) for 1 cup/day (1 cup = 300 ml), 0.84 (0.77, 0.93) for 2 cups/day, 0.85 (0.77, 0.92) for 3 cups/day, 0.88 (0.81, 0.96) for 4 cups/day, and 0.92 (0.82, 1.04) for 5 cups/day.
Conclusions: This updated meta-analysis of studies from East Asia suggests that green tea consumption may be associated with a reduced risk of CHD, especially among those with low-to-moderate consumption. Additional cohorts are still needed before we could draw a definitive conclusion.
Systematic review registration: PROSPERO CRD42022357687.
Keywords: CHD; Dose–response; Green tea; Meta-analysis; Prospective studies.
Copyright © 2023 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.