British Journal of Nutrition

Human and Clinical Nutrition

Ceylon cinnamon does not affect postprandial plasma glucose or insulin in subjects with impaired glucose tolerance

Jennie Wickenberga1a2, Sandra Lindstedta3, Kerstin Berntorpa4, Jan Nilssona1a2 and Joanna Hlebowicza1a2a5 c1

a1 Center for Emergency, Skåne University Hospital, Lund University, Malmö, Sweden

a2 Department of Clinical Science, Lund University, Malmö, Sweden

a3 Department of Cardio-thoracic Surgery, Skåne University Hospital, Lund University, Lund, Sweden

a4 Department of Endocrinology, Skåne University Hospital, Lund University, Malmö, Sweden

a5 Department of Cardiology, Skåne University Hospital, Entrance 35, SE-205 02 Malmö, Sweden


Previous studies on healthy subjects have shown that the intake of 6 g Cinnamomum cassia reduces postprandial glucose and that the intake of 3 g C. cassia reduces insulin response, without affecting postprandial glucose concentrations. Coumarin, which may damage the liver, is present in C. cassia, but not in Cinnamomum zeylanicum. The aim of the present study was to study the effect of C. zeylanicum on postprandial concentrations of plasma glucose, insulin, glycaemic index (GI) and insulinaemic index (GII) in subjects with impaired glucose tolerance (IGT). A total of ten subjects with IGT were assessed in a crossover trial. A standard 75 g oral glucose tolerance test (OGTT) was administered together with placebo or C. zeylanicum capsules. Finger-prick capillary blood samples were taken for glucose measurements and venous blood for insulin measurements, before and at 15, 30, 45, 60, 90, 120, 150 and 180 min after the start of the OGTT. The ingestion of 6 g C. zeylanicum had no significant effect on glucose level, insulin response, GI or GII. Ingestion of C. zeylanicum does not affect postprandial plasma glucose or insulin levels in human subjects. The Federal Institute for Risk Assessment in Europe has suggested the replacement of C. cassia by C. zeylanicum or the use of aqueous extracts of C. cassia to lower coumarin exposure. However, the positive effects seen with C. cassia in subjects with poor glycaemic control would then be lost.

(Received March 23 2011)

(Revised August 16 2011)

(Accepted August 16 2011)

(Online publication September 20 2011)


c1 Corresponding author: J. Hlebowicz, fax +46 40 92 32 72, email


Abbreviations: AUC, area under the curve; GI, glycaemic index; GII, glycaemic insulinaemic index; IGT, impaired glucose tolerance; OGTT, oral glucose tolerance test