Effects of Different Morus alba L. Parts on Glycemic and Lipid Profiles: A Systematic Review and Meta-Analysis

Metabolic syndrome is a growing global health challenge. Given the limitations of conventional therapies, mulberry (Morus alba L.) has gained attention as a functional food with potential metabolic benefits. This systematic review and meta-analysis evaluated recent evidence on its efficacy and safety across various plant parts. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered with PROSPERO (CRD42024600762). Randomized controlled trials (RCTs) were identified from PubMed, Embase, Scopus, and gray literature sources, up to May 2025. Risk of bias was assessed using the Risk of Bias 2 tool. Meta-analysis applied a random-effects model, with subgroup analyses to explore heterogeneity. Eighteen RCTs were included in this review. The meta-analysis showed that single mulberry intervention significantly lowered postprandial glucose (PPG) levels compared to the control group at 30 min (MD = −10.37 mg/dL; 95% CI: −19.30 to −1.45; p = 0.02) and 60 min (MD = −6.01 mg/dL; 95% CI: −11.97 to −0.05; p = 0.05). In addition, significant reductions were observed in the PPG area under the curve (AUC), PPG-positive incremental AUC, and the postprandial insulin (PPI) total AUC over 120 min. The leaf subgroup showed notable effects on both PPG and PPI levels. For long-term effects, 4 - 16 weeks of mulberry intervention significantly lowered glycated hemoglobin A1c (HbA1c) (MD = −0.30%; 95% CI: −0.56 to −0.05; p = 0.02), with no significant changes in fasting blood glucose (FBG), fasting plasma insulin (FPI), or lipid profiles. Mulberry treatment was well tolerated and considered safe for use. Mulberry, particularly the leaf, demonstrated significant efficacy in improving postprandial glycemic responses and HbA1c levels, with a favorable safety profile. Further research is called for to assess any long-term effects and the potential of other plant parts. HIGHLIGHTS Single administration of mulberry products significantly reduced postprandial glycemic responses, including glucose and insulin parameters. Long-term use (4 - 16 weeks) improved HbA1c levels but showed no effect on fasting blood glucose, insulin, and lipid profiles. Mulberry leaf subgroup demonstrated reductions in both postprandial glucose and insulin, as well as a significant decrease in HbA1c, supporting its potential as a functional food for glycemic control. Mulberry interventions were well tolerated overall, with gastrointestinal symptoms as the most frequent adverse events. No serious adverse events were reported. GRAPHICAL ABSTRACT