Effects of Propolis Consumption on Glycemic Indices and Liver Enzymes in Adults: A Grading of Recommendations Assessment, Development, and Valuation-assessed Systematic Review and Dose-Response Meta-analysis

Abstract

Purpose: Even though various randomized controlled trials (RCTs) have assessed the effect of propolis on glycemic indices and liver enzyme concentrations in adults, results have been inconsistent, without conclusive evidence. This systematic review and meta-analysis of RCTs sought to evaluate the effects of propolis consumption on glycemic indices and liver enzymes, fasting blood glucose, insulin, homeostatic model assessment of insulin resistance, glycosylated hemoglobin, alanine transaminase, aspartate aminotransferase, and gamma-glutamyl transferase in adults. Methods: Two independent researchers systematically searched PubMed, EMBASE, Scopus, Web of Science, and the Cochrane Library for English-language RCTs published up to April 2024. The results were generated through a random-effects model and presented as the weighted mean difference (WMD) with a 95 CI. The Cochrane Risk of Bias Tool for RCTs and Grading of Recommendations Assessment, Development, and Evaluation assessment were used to evaluate quality assessment and certainty of evidence. Findings: A total of 21 RCTs were included. A pooled analysis of 24 trials reported that propolis consumption led to a significant reduction in fasting blood glucose (WMD, - 9.75 mg/dL; 95 CI, - 16.14 to - 3.35), insulin (WMD, - 1.64 mu U/mL; 95 CI, - 2.61 to - 0.68), glycosylated hemoglobin (WMD, - 0.46; 95 CI, - 0.71 to - 0.21), homeostatic model assessment of insulin resistance (WMD, - 0.54; 95 CI, - 0.98 to - 0.09), alanine transaminase (WMD, - 2.60 IU/L; 95 CI, - 4.58 to - 0.61), and aspartate aminotransferase (WMD, - 2.07 IU/L; 95 CI, - 3.05 to - 1.09). However, there were no significant effects on gamma-glutamyl transferase in comparison with the control group. Implications: This meta-analysis has shown that propolis supplementation may have beneficial effects on glycemic indices and liver enzymes. Future high-quality, long-term RCTs are needed to confirm our results. (c) 2024ElsevierHSJournals,Inc.