Effect of green tea on glycemic control in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Background and aims: Several studies have investigated the potential beneficial effects of green tea in patients with type 2 diabetes mellitus (T2DM). Therefore, we aimed to perform a systematic review and meta-analysis of the randomized controlled trials (RCTs) that assessed the effect of supplementary intake of green tea on fasting plasma glucose (FPG), fasting insulin, hemoglobin A1c (HbA1c) and HOMA-IR in patients with T2DM. Methods: A systematic search was performed in Web of Science, PubMed and Scopus without any language and time restriction up to June 2019, to retrieve the related RCTs. Meta-analysis was carried out using both the random and fixed effects model where appropriate. I2 index was used to evaluate the heterogeneity. Results: Initial search yielded 780 publications. Fourteen articles were eligible. Our meta-analysis indicated that the supplementary intake of green tea had no significant effect on FPG, fasting insulin, HbA1c and HOMA-IR in patients with T2DM. Conclusion: Results of the present systematic review and meta-analysis indicated that the supplementary intake of green tea had no significant effect on FPG, fasting insulin, HbA1c and HOMA-IR in patients with T2DM. (C) 2020 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study conducted a systematic review and meta-analysis on the potential effects of supplementary intake of green tea in patients with type 2 diabetes mellitus, and found that it had no significant impact on fasting plasma glucose, fasting insulin, hemoglobin A1c, and HOMA-IR.