The effects of propolis supplementation on lipid profiles in adults with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials

Background and aim: Findings on the effects of propolis supplementation on the lipid profile in adults with metabolic syndrome (MetS) and related disorders are conflicting. The current comprehensive systematic review and meta -analysis aimed to summarize available evidence in this regard. Methods: Online databases including PubMed, Scopus, Web of Science, and Cochrane Library were searched up to May 2024 for randomized controlled trials (RCTs) that examined the effect of propolis supplementation on lipid profile in adults with MetS and related disorders. The data was pooled using a random -effects model and is presented as weighted mean difference (WMD) with a 95 % confidence interval (CI). Results: Ten RCTs involving a total of 683 subjects were included in this meta -analysis. The combined results revealed that propolis supplementation led to a significant decrease in low -density lipoprotein cholesterol (LDLC) levels (WMD: -7.97 mg/dL, 95 % CI: -13.11 to -2.83, P = 0.002; I 2 = 69.9 %) and a significant increase in high -density lipoprotein cholesterol (HDL-C) levels (WMD: 2.85 mg/dL, 95 % CI: 0.41 to 5.28, P = 0.02; I 2 = 82.2 %). However, there was no significant impact on triglyceride (WMD: -9.12 mg/dL, 95 % CI: -22.84 to 4.59, P = 0.19; I 2 = 0.0 %) and total cholesterol levels (WMD: 0.69 mg/dL; 95 % CI: -4.79 to 6.18, P = 0.80; I 2 = 81.9 %). Conclusions: This meta -analysis suggests that propolis supplementation improves serum LDL-C and HDL-C levels, which could delay the progression of heart disease. However, these results were based on limited RCTs, and further clinical trials are needed to exclusively study the effects of propolis on individuals with dyslipidemia to confirm our findings.