Influence of Cinnamon on Glycemic Control in Individuals With Prediabetes: A Randomized Controlled Trial

Abstract

Abstract Context The identification of adjunct safe, durable, and cost-effective approaches to reduce the progression from prediabetes to type 2 diabetes (T2D) is a clinically relevant, unmet goal. It is unknown whether cinnamon’s glucose-lowering properties can be leveraged in individuals with prediabetes. Objective The objective of this work is to investigate the effects of cinnamon on measures of glucose homeostasis in prediabetes. Design, Setting, Participants, and Intervention This double-blind, placebo-controlled, clinical trial randomly assigned adult individuals meeting any criteria for prediabetes to receive cinnamon 500 mg or placebo thrice daily (n = 27/group). Participants were enrolled and followed at 2 academic centers for 12 weeks. Main Outcome Measures Primary outcome was the between-group difference in fasting plasma glucose (FPG) at 12 weeks from baseline. Secondary end points included the change in 2-hour PG of the oral glucose tolerance test (OGTT), and the change in the PG area under the curve (AUC) derived from the OGTT. Results From a similar baseline, FPG rose after 12 weeks with placebo but remained stable with cinnamon, leading to a mean between-group difference of 5 mg/dL (P < .05). When compared to the respective baseline, cinnamon, but not placebo, resulted in a significant decrease of the AUC PG (P < .001) and of the 2-hour PG of the OGTT (P < .05). There were no serious adverse events in either study group. Conclusions In individuals with prediabetes, 12 weeks of cinnamon supplementation improved FPG and glucose tolerance, with a favorable safety profile. Longer and larger studies should address cinnamon’s effects on the rate of progression from prediabetes to T2D.