Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects 1-3 Joanna Hlebowicz, Gassan Darwiche, Ola Björgell, and Lars-Olof Almér ABSTRACT Background: Previous studies of patients with type 2 diabetes showed that cinnamon lowers fasting serum glucose, triacylglycerol, and LDL- and total cholesterol concentrations. Objective: We aimed to study the effect of cinnamon on the rate of gastric emptying, the postprandial blood glucose response, and sa- tiety in healthy subjects. Design: The gastric emptying rate (GER) was measured by using standardized real-time ultrasonography. Fourteen healthy subjects were assessed by using a crossover trial. The subjects were examined after an 8-h fast if they had normal fasting blood glucose concentra- tions. GER was calculated as the percentage change in the antral cross-sectional area 15–90 min after ingestion of 300 g rice pudding (GER1) or 300 g rice pudding and 6 g cinnamon (GER2). Results: The median value of GER1 was 37%, and that of GER2 was 34.5%. The addition of cinnamon to the rice pudding significantly delayed gastric emptying and lowered the postprandial glucose re- sponse (P  0.05 for both). The reduction in the postprandial blood glucose concentration was much more noticeable and pronounced than was the lowering of the GER. The effect of cinnamon on satiety was not significant. Conclusions: The intake of 6 g cinnamon with rice pudding reduces postprandial blood glucose and delays gastric emptying without affecting satiety. Inclusion of cinnamon in the diet lowers the post- prandial glucose response, a change that is at least partially explained by a delayed GER. Am J Clin Nutr 2007;85:1552– 6. KEY WORDS Gastric emptying, blood glucose, healthy sub- jects, cinnamon, diabetes, satiety INTRODUCTION Around the world, the incidence of type 2 diabetes mellitus is increasing rapidly. Changing the diet helps to prevent develop- ment of type 2 diabetes and to control blood glucose concentra- tions. Traditional herbs and spices also can be used to control blood glucose concentrations. Allspice, cinnamon, bay leaf, cloves, nutmeg, witch hazel, oregano, and black and green tea have been shown to have an insulin-like biological activity (1). Of these substances, cinnamon has been shown to have the high- est bioactivity (1). A water-soluble polyphenol typ-A polymer from cinnamon has been isolated and shown in vitro to have insulin-like activity as well as an antioxidant effect (2). Cinna- mon has been shown to reduce fasting serum glucose, triacyl- glycerol, and total and LDL-cholesterol concentrations in pa- tients with type 2 diabetes when it is added to the diet for 40 d in doses of 1, 3, or 6 g (3). The same study showed that, after the consumption of cinnamon for 40 d, the serum concentrations of glucose and triacylglycerol remained lower, even after a 20-d washout period (3), which indicated that it is not necessary to consume cinnamon every day (3). The effect of cinnamon on gastric emptying has not previously been studied. Gastric emptying, along with other factors, regu- lates the postprandial blood glucose response, and a delay in the gastric emptying rate (GER) leads to a lower postprandial blood glucose concentration. Therefore, this study was designed to determine whether there is a delay in gastric emptying that affects postprandial blood glucose concentrations and satiety in healthy subjects after cinnamon consumption. SUBJECTS AND METHODS Fourteen healthy subjects [8 M, 6 F; x   SD age: 25.6  4.8 y (range: 20 –38 y); body mass index (BMI; in kg/m 2 ): 22.6  2.2 (range: 18.4 –26.0)] without symptoms or a history of gastroin- testinal disease, abdominal surgery, or diabetes mellitus were included in the crossover study. The subjects had no connective tissue disease or cerebrovascular or endocrine disease, and only the 4 women who took birth control medication were receiving any drugs. Two subjects were smokers and 2 were snuff users. All subjects were recruited from the population in southern Sweden. The subjects were examined between 0730 and 1000 after an 8-h fast. Smoking and snuff-taking were prohibited for 8 h before and during the test. Each subject was checked for a normal fasting blood glucose concentration on the day of the examination. If the subjects reported symptoms from the gastrointestinal tract (di- arrhea or constipation) on the study day, the examination was postponed. The test meal consisted of 300 g rice pudding (Axa Goda Gröten Risgrynsgröt; Lantma ¨nnen AXA, Ja ¨rna, Sweden) mixed with 6 g cinnamon (Santa Maria AB, Mölndal, Sweden). The total caloric value was 330 kcal: 10% of energy from protein (3 g), 58% of energy from carbohydrate (16 g), and 32% of energy from fat (4 g). The reference meal consisted of 300 g rice 1 From the Departments of Medicine (JH, GD, and L-OA) and Radiology (OB), Malmö University Hospital, University of Lund, Lund, Sweden. 2 Supported by grants from the Malmö Diabetes Association. 3 Address reprint requests to J Hlebowicz, Department of Medicine, Malmö University Hospital, Ingång 35, 205 02 Malmö, Sweden. E-mail: joanna.hlebowicz@skane.se. Received July 12, 2006. Accepted for publication January 24, 2007. 1552 Am J Clin Nutr 2007;85:1552– 6. Printed in USA. © 2007 American Society for Nutrition by guest on August 17, 2015 ajcn.nutrition.org Downloaded from