The Efficacy of Cinnamon Supplementation for Glycemic Control in Type 2 Diabetes: A Systematic Review and Meta-Analysis

Abstract

Introduction: Type 2 Diabetes Mellitus (T2DM) is a global health crisis. Cinnamon has been investigated as a potential glucose-lowering agent, but its clinical efficacy remains debated. This review aims to synthesize the evidence from randomized controlled trials (RCTs) on the effect of cinnamon on glycemic control in T2DM patients.

Methods: A comprehensive search of MEDLINE, Embase, and the Cochrane Library was conducted. We included placebo-controlled RCTs that evaluated any type of cinnamon preparation in T2DM patients. The primary outcomes were changes in Glycated Hemoglobin (HbA1c) and Fasting Blood Glucose (FBG).

Results: The meta-analysis of 18 RCTs showed that cinnamon supplementation resulted in a statistically significant reduction in FBG compared to placebo. However, the effect on HbA1c was modest and did not reach statistical significance in the overall analysis, though some subgroups showed a benefit.

Discussion: Cinnamon appears to have a favorable short-term effect on fasting glucose levels, but its impact on long-term glycemic control (HbA1c) is not well-established. Heterogeneity in cinnamon species, dosage, and study duration may explain the variable results.

Conclusion: Current evidence suggests cinnamon may be a useful adjunct for lowering fasting glucose but is insufficient to recommend it for long-term HbA1c management.