Abstract Aim: Oxidative stress represents a cornerstone of a wide range of chronic diseases. Studies have identified an inconsistent effect of green tea on regulating oxidative stress. We aimed to examine the evidence from randomized clinical trials (RCTs) to assess the effects of green tea on oxidative stress markers including malondialdehyde (MDA), and total antioxidant capacity (TAC) in adults. Methods: A systematic search of English language publications in PubMed, Scopus and Embase was performed up to September 1, 2020. Data were pooled using the random-effects method and were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). Results: Fourteen RCTs met inclusion criteria. There was a significant relationship between green tea and TAC. Our results indicated that green tea had significant effects on TAC (weighted mean difference [WMD]: 0.18; 95 % CI, 0.07, 0.29, P =0.001) and significant heterogeneity between studies (I2 = 98.6%, p <0.001) which was largely related to sex and BMI. Subgroup analysis in TAC identified a significant relationship except in low dose and obese individuals. No relationship between MDA and green tea was observed overall and in all subgroups. Conclusions: We found that the intervention with green tea significantly increased the TAC, while, it had no significant effect on MDA. Key Words: green tea, oxidative stress, total antioxidant capacity, malondialdehyde.

Background: Prior research has yielded mixed results regarding the impact of acarbose intake on glycemic markers. To provide a more comprehensive analysis, a systematic review and meta-analysis was performed to compile data from various randomized controlled trials (RCTs) examining the effects of acarbose intake on fasting blood sugar (FBS), insulin, hemoglobin A1C (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR) in adults. Methods: To identify relevant literature up to April 2023, a comprehensive search was conducted on various scholarly databases, including PubMed, Web of Science, and Scopus databases. The effect size of the studies was evaluated using a random-effects model to calculate the weighted mean differences (WMD) and 95% confidence intervals (CI). Heterogeneity between studies was assessed using Cochran’s Q test and I2. Results: This systematic review and meta-analysis included a total of 101 RCTs with a total of 107 effect sizes. The effect sizes for FBS in milligrams per deciliter (mg/dl), insulin in picomoles per liter (pmol/l), hemoglobin A1C (HbA1c) in percentage (%), and homeostasis model assessment of insulin resistance (HOMA-IR) were 92, 46, 80, and 22, respectively. The pooled analysis indicated that acarbose intake resulted in significant decreases in FBS (p=0.018), insulin (p<0.001), HbA1c (p<0.001), and HOMA-IR (p<0.001). Conclusion: The findings of this systematic review and meta-analysis suggest that acarbose intake can potentially lead to significant improvements in glycemic indices by decreasing the levels of FBS, HbA1c, and insulin. However, larger and more rigorously designed studies are still needed to further evaluate and strengthen this association.