Effect of Cinnamon on Glucose and Lipid Levels in Non–Insulin-Dependent Type 2 Diabetes

Interest in cinnamon as a potentially useful treatment for type 2 diabetes began with the discovery almost 20 years ago of cinnamon’s insulin-sensitizing properties (1). Numerous in vitro and in vivo studies have elucidated cinnamon’s effect on insulin signal transduction (2–6). A study in diabetic mice showed that cinnamon lowered blood glucose, total cholesterol, and triglyceride levels while raising HDL cholesterol levels (7). The first clinical trial to evaluate the effect of cinnamon in individuals with type 2 diabetes was conducted in Pakistan (8). It showed that cinnamon powder (Cinnamomum cassia), taken over a 40day period, reduced mean fasting serum glucose (18–29%), triglyceride (23– 30%), LDL cholesterol (7–27%), and total cholesterol (12–26%) levels. Three different doses of cinnamon were administered: 1, 3, and 6 g daily. All were equally effective. These findings led to widespread cinnamon use, although no study had yet evaluated the effects of cinnamon in Western diabetic populations with likely differences in diet, BMI, baseline glucose levels, and prescribed medication. We report the first U.S. study examining the effects of cinnamon on glucose and lipid levels in subjects with type 2 diabetes.