In individuals with prediabetes, 12 weeks of cinnamon supplementation improved blood sugar control, found a small, randomised international clinical trial.
The study, by researchers at Kyung Hee University in Seoul, the Joslin Diabetes Centre-Boston and the Landstuhl Regional Medical Centre in Landstuhl, Germany, was published in the Journal of the Endocrine Society.
It is estimated that nearly 90m people in the US have prediabetes, which occurs when blood sugar levels are higher than normal and often leads to type 2 diabetes. Identifying strategies to prevent the progression from prediabetes to type 2 diabetes is challenging, yet important for a large population.
“Our 12-week study showed beneficial effects of adding cinnamon to the diet on keeping blood sugar levels stable in participants with prediabetes,” said the study’s corresponding author, Dr Giulio R Romeo, of Joslin Diabetes Centre in Boston. “These findings provide the rationale for longer and larger studies to address if cinnamon can reduce the risk of developing type 2 diabetes over time.”
The randomised clinical trial investigated the effects of cinnamon supplementation in 51 participants with prediabetes. Participants were given a 500 mg cinnamon capsule or placebo three times a day for 12 weeks. The researchers found that cinnamon supplements lowered abnormal fasting glucose levels and improved the body’s response to eating a meal with carbohydrates, which are hallmarks of prediabetes. Cinnamon was well tolerated and was not associated with specific side effects or adverse events.
The study was supported by the Ministry of Health and Welfare in South Korea.
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 if cinnamon’s glucose-lowering properties can be leveraged in individuals with prediabetes.
Objective: 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 randomized adult subjects meeting any criteria for prediabetes to receive cinnamon 500 mg or placebo thrice daily (n=27/group). Participants were enrolled and followed at two 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 endpoints included the change in 2-hr 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<0.05). When compared to the respective baseline, cinnamon, but not placebo, resulted in a significant decrease of the AUC PG (P<0.001) and of the 2-hr PG of the OGTT (P<0.05). 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.
Giulio R Romeo, Junhee Lee, Christopher M Mulla, Youngmin Noh, Casey Holden, Byung-Cheol Lee
Endocrine Society material
Journal of the Endocrine Society abstract