Cinnamon is a spice that has been used since ancient times for medicinal purposes. Recently, cinnamon has become a hot topic in diabetes research.
Studies showing cinnamon as an effective diabetic treatment have proposed that cinnamon may have an insulin-like effect on cells -- triggering cells to take glucose out of the blood -- or that cinnamon may cause an increase in the activity of the transporter proteins that move glucose out of the blood stream and into cells.
As with all dietary supplements, it should be noted that supplements are not regulated by the FDA, leaving the door open to manufacturing risks. In addition, cinnamon may increase the risk of liver problems and reduce the blood's ability to clot. Because cinnamon may lower blood-sugar levels, caution should be exercised when combining it with other common diabetic medications and/or supplements that may also lower sugar levels. Some of these supplements include: alpha lipoic acid, bitter melon, chromium, devil's claw, fenugreek, garlic, horse chestnut, Panax, Siberian ginseng, and psyllium.
Though some studies have shown cinnamon can improve glucose and lipid levels in type 2 diabetics, other studies have not shown cinnamon to improve glycemic control. Since the data regarding cinnamon's efficacy in reducing glucose levels is inconsistent, the American Diabetic Association does not endorse the use of cinnamon as a therapy for diabetes at this time.
Baker et al. "Effect of Cinnamon on Glucose Control and Lipid Parameters." Diabetes Care. 2008;31:41-3
Khan, MS, PHD, Alam, Safdar, MS, Mahpara, Ali Khan, MS, PHD, Mohammad Muzaffar, Khattak, MS, Khan Nawaz, and Anderson, PHD, Richard A. "Cinnamon Improves Glucose and Lipids of People with Type 2 Diabetes." Diabetes Care. 2003;26:3215-3218.
Vanschoonbeek K et al. "Cinnamon Supplementation Does Not Improve Glycemic Control in Postmenopausal Type 2 Diabetes Patients". Journal of Nutrition. 2006;136:977-980