Tea consumption in relation with metabolic syndrome and obesity: A systematic review and meta-analysis of randomized clinical trials

Background: The worldwide prevalence of metabolic syndrome (MS) and obesity has led to the exploration of tea consumption as a potential strategy for managing these conditions. However, the clinical outcomes remain debated. We conducted a meta-analysis to evaluate the benefits of tea supplementation in MS and obesity entirely based on randomized controlled trials (RCTs). Methods: Databases of PubMed, Cochrane library, MEDLINE and Web of Science were searched through May 2023 to identify eligible RCTs evaluating the effects of tea supplementation related to MS and obesity. Results were summarized using standardized mean differences (SMDs) by suitable effect model. Results: A total of 24 RCTs were screened, including 1672 subjects from 8 countries. Tea supplementation reduced body weight (BW) (SMD:-0.14; 95%CI:-0.26,-0.03; P = 0.013), body mass index (BMI) (SMD:- 0.15; 95%CI:-0.26,-0.03; P = 0.016), triglycerides (TG) (SMD:-0.21; 95% CI:-0.41,-0.01; P = 0.044), total cholesterol (TC) (SMD:-0.23; 95% CI:-0.44,-0.02; P = 0.033), low-density lipoprotein cholesterol (LDLC) (SMD:-0.28; 95% CI:-0.5,-0.05; P = 0.016) and hemoglobin A1c (HbA1c) (SMD:-0.35; 95% CI:-0.60,- 0.1; P = 0.007) levels, increased high-density lipoprotein (HDL) (SMD: 0.13; 95% CI: 0.01, 0.25; P = 0.04) levels versus Placebo. Conclusion: This meta-analysis presents convincing evidence of the potential advantages of tea consumption for individuals with MS and obesity. Compared with control group, tea consumption can significantly reduce BW, BMI, and lipid profiles (HDL-C, LDL-C, TG, TC) levels of obesity and MS patients. This beneficial effect highlights the prospect of tea as a beneficial dietary strategy in addressing these medical conditions.