Metabolic syndrome (MetS) is a cluster of risk factors that significantly increase the chances of developing heart disease, type 2 diabetes mellitus, stroke, and other cardiovascular complications. Since current anti-MetS medications like statins, angiotensin-converting enzyme inhibitors, β-blockers, insulin sensitizers and diuretics have been reported to cause unwanted side effects, researchers are exploring promising alternatives. One such alternative relies on the potential of spices and condiments, which have a long history of use in traditional medicine. Among them, Cinnamomum zeylanicum Blume stands out as a popular spice worldwide for its unique taste, aroma, and delicate sweetness compared to other cinnamon varieties. This narrative review aims to summarize the in vivo and clinical evidence concerning the efficacy of C. zeylanicum against MetS indices. Relevant articles from PubMed, Scopus and Google scholar databases were reviewed. In vivo results suggested that C. zeylanicum preparations (extracts, essential oil, crude powder, bioactive compounds, and biosynthesized nanoparticles) were remarkably efficient in ameliorating MetS indices, while the clinical data were less and with several methodological limitations. Further robust clinical studies are warranted to definitively establish C. zeylanicum as a promising functional food for mitigating MetS, potentially leading to its dietary integration as a natural approach to improve metabolic health.

Key words: Metabolic syndrome, True cinnamon, In vivo, Clinical trial, Gut microbiota, Hypertension