Sumac ( Rhus coriaria L. ) and Human Metabolic Health: A Systematic Review and Meta‐Analysis

BACKGROUND: Rhus coriaria L. (Anacardiaceae), known as Sumac, is a commonly used spice, which is rich in various classes of phytochemicals including flavonoids, tannins, polyphenolic compounds, organic acids, and may be beneficial for cardiovascular disease risk factors. This comprehensive systematic review and meta-analysis aimed to assess the impact of Sumac supplementation on cardiovascular disease risk factors, including anthropometric measures, glycemic profile, inflammatory markers, and lipid profile. Additionally, we explored the dose-response relationship and optimal duration of Sumac supplementation for its effects on cardiovascular risk factors. METHODS: Relevant randomized clinical trials were identified through electronic database searches (PubMed, Scopus, Web of Science, CENTRAL, and EMBASE) up to March 2025. The Cochrane risk-of-bias tool was employed to evaluate study quality. Standardized mean differences (SMDs) in changes between intervention and placebo groups were calculated. A random-effects model, meta-regression, and non-linear modeling explored heterogeneity, dose-response relationships, and the overall impact of Sumac supplementation. RESULTS: Fifteen trials, with interventions ranging from 4 to 12 weeks and involving 917 participants, were included. Sumac supplementation demonstrated significant improvements in glycemic and lipid profile. Conversely, no significant effects were observed on other cardiovascular risk factors. CONCLUSIONS: Sumac supplementation improved lipid profile, and glycemic parameters suggesting potential benefits in addressing cardiovascular risk factors, despite no significant effects on inflammatory parameters.