Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2004
Publication Date: March 1, 2004
Citation: Anderson, R.A. 2004. Cinnamon and tea as insulin sensitizers [abstract]. Rencontres de Physionutrition. Vol. 3: Abs. #3. Technical Abstract: Decreased insulin sensitivity leads to the inability of insulin to control the utilization and storage of glucose. We have shown recently that polyphenols from cinnamon improve insulin sensitivity, glucose uptake and glycogen synthesis. There is an activation of insulin receptor kinase and an inhibition of insulin receptor phosphatase leading to increased phosphorylation of the insulin receptor with the accompanying increases in insulin sensitivity. The active components were shown to be A type doubly linked procyanidin oligomers of the catechins and/or epicatechins. The improvements in insulin function in vitro were substantiated in subjects with type 2 diabetes. There were significant decreases in fasting serum glucose (18-29%), triglycerides (23-30%), total cholesterol (12 to 26 %), and LDL cholesterol (7-27%) after 40 days in subjects consuming as little as 1 g of cinnamon per day. The antioxidant properties of tea catechins are well established with the largest effects of epigallocatechin gallate. The insulin potentiating activity of tea components is also greatest for epigallocatechin gallate followed by gallocatechin gallate and epicatechin gallate. Tannins and theaflavins also display some insulin potentiating activity. Green, black and oolong teas, but not herbal teas, display insulin potentiating activity. Polyphenols from tea have also been shown to inhibit glucose uptake at the gut level and also to inhibit gluconeogenesis. Recent studies also demonstrate that tea may play a role in the improvements of glucose and insulin in human subjects. In summary, polyphenols from cinnamon and tea improve glucose and insulin function. Improvements have been observed in cell culture, animal and human studies.