Cinnamon for type 2 diabetes

Townsend Letter for Doctors and Patients, May, 2007 by Alan R. Gaby

Sixty patients (mean age, 52.2 years) with type 2 diabetes who were not on insulin therapy were randomly assigned to receive (blinding not specified) cinnamon at a dose of 1, 3, or 6 g per day or placebo for 40 days. Compared with baseline, all three doses of cinnamon reduced the mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL-cholesterol (7-27%), and total-cholesterol (12-26%) levels; the responses to the three doses were similar. The reductions in fasting glucose and triglyceride levels were all significant (p < 0.05) compared with placebo, and some but not all the reductions in total- and LDL-cholesterol levels were significant compared with placebo.

Comment: Extracts of cinnamon have been shown to increase in vitro glucose uptake. In addition, cinnamon extracts are believed to aid in triggering the insulin cascade. The results of the present study demonstrate that daily supplementation with 1 g of cinnamon can improve glucose and lipid levels in patients with type 2 diabetes.

Two other studies have investigated the effect of cinnamon in patients with type 2 diabetes. In one of these studies, cinnamon was somewhat less effective than in the present study (Eur J Clin Invest. 2006;36:340-344); in the other study, cinnamon was not beneficial compared with placebo (J Nutr. 2006;136:977-980). It is not clear why the results of these studies differed.

Other than occasionally causing oral mucosal reactions, cinnamon appears to be safe. Therefore, a therapeutic trial would seem reasonable for patients with type 2 diabetes.

Khan A, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. 2003;26:3215-3218.