The study, published in the American Journal of Clinical Nutrition , adds to a growing body of research reporting that active compounds in cinnamon may improve parameters associated with diabetes.
"Inclusion of cinnamon in the diet lowers the postprandial glucose response, a change that is at least partially explained by a delayed [gastric emptying rate]," wrote lead author Joanna Hlebowicz from Malmo University Hospital, University of Lund The researchers measured the rate of stomach emptying (gastric emptying rate) in 14 healthy subjects with normal fasting blood glucose levels after consuming 300 grams of rice pudding or 300 g rice pudding plus 6 g cinnamon.
Using standardised real-time ultrasonography, the rate of gastric emptying rate was measured in the antral cross-sectional area 15-90 min after eating the rice pudding.
The subjects were crossed over to receive the alternative rice pudding.
The Swedish researchers report that addition of cinnamon to the rice pudding reduced gastric emptying from 37 to 34.5 per cent, and also delayed the rise in blood glucose levels after eating.
No effect of cinnamon was found on satiety.
"The intake of 6 g cinnamon with rice pudding reduces postprandial blood glucose and delays gastric emptying without affecting satiety," they concluded.
The new research is in-line with other studies into the potential benefits of the spice.
A previous study by the U.S. Department of Agriculture reported in 2003 ( Diabetes Care , Vol. 26, pp. 3215-3218) that just 1g of the spice per day reduced blood glucose levels, as well as triglycerides, LDL cholesterol, and total cholesterol in a small group of people with type 2 diabetes.
A placebo-controlled, double-blind study published in 2006 ( Journal of the American College of Nutrition , Vol. 25, pp.
144-150) reported that cinnamon and a cinnamon extract (Cinnulin PF) could reduce blood pressure in spontaneously hypertensive rats (SHR).
However, there have been toxicity concerns over consistent consumption or high doses of whole cinnamon or fat-soluble extracts.
Indeed, two federal institutes in Germany recently called for cinnamon dietary supplements carrying health claims to reduce blood sugar and help control type-2 diabetes should be classed as 'medicinal products', and regulated as such.
The joint announcement from the Federal Institute for Medicinal Products and MedicalDevices (BfArM) and the Federal Institute for Risk Assessment (BfR) states their opinion that products marketed with a diabetes health claim should be classified as medicinal products and required to seek marketing authorisation.
The concerns came about from differing coumarin levels in some products, said to cause liver damage and inflammation when higher doses are taken over a longer period by sensitive individuals.
Not all cinnamon capsules contain such harmful products, however.
Indeed, researchers at the USDA have performed significant research into a water-extract of cinnamon, marketed as Cinnulin PF, by Integrity Nutraceuticals International.
According to Integrity, Cinnulin PF contains standardized quantities of the active components of cinnamon, two trimers and one tetramer classified as double-linked type-A polymers, but not the potentially harmful compounds.
Cinnulin PF is claimed to be the only cinnamon extract standardized for these compounds.
Source: American Journal of Clinical Nutrition June 2007, Vol. 85, No. 6, Pages 1552-1556 "Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects" Authors: J. Hlebowicz, G. Darwiche, O. Bjorgell and L.-O. Almer