Sixty people (mean age, 52.2 years) with type 2 diabetes who were not on insulin therapy were randomly assigned to receive cinnamon (1, 3, or 6 g/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 all the doses of cinnamon were similar. No significant changes were noted in the placebo group. The reductions in mean fasting serum glucose and triglyceride levels were all significant (p < 0.05) compared with placebo, and some but not all of the reductions in total- and LDL-cholesterol levels were significant compared with placebo.

Comment: These results indicate that daily ingestion of a modest amount of cinnamon (1 g/day or more) significantly reduced serum glucose and triglyceride levels, and possibly reduced serum total- and LDL-cholesterol levels in patients with type 2 diabetes. In previous studies, extracts of cinnamon have been shown to increase glucose uptake in vitro. In addition, cinnamon appears to aid in triggering the insulin cascade (the series of biochemical actions stimulated by insulin). Taking cinnamon is an inexpensive and apparently safe way to improve glucose levels and other metabolic abnormalities that occur in people 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.