This is consistent with our proposed mechanism of action. 1-5 According to many health and regulatory bodies, chromium(III) has minimal or no efficacy in glucose metabolism and no other beneficial effects, such as weight loss or muscle building, in well conducted human and animal trials with non-diabetic subjects. The faster a particular chromium(III) supplement reacted with blood proteins to form these easily oxidised chromium(III)-protein species, the more active was the Cr(III) supplement in its anti-diabetic activity in animal and human studies reported by other groups. These transformed chromium(III) species bound to blood proteins were more easily oxidised to chromium(VI) than the administered Cr(III) supplements. These oxidants are associated with many of the side-effects of type II diabetes that are associated with reduced life expectancy. 1,2 One of the clinical features of patients with type II diabetes is increased levels of oxidants, such as hydrogen peroxide, in their blood and cells. Both the supplements themselves and the chromium(III) species that formed in blood serum were partially oxidised to Cr(VI) at concentrations of the oxidant, hydrogen peroxide (a type of bleach), found in the blood of people with type II diabetes. 1,2 Common species were observed, but the rates at which they formed were dependent on the nature of the chromium(III) supplement. We discovered that all supplements were changed to a range of different Cr(III) species in both the GI tract and the blood.

This work commenced some 15 years ago with studies on the changes in the nature of chromium(III) supplements exposed to simulated gastrointestinal juices, as well as in human and animal blood serum over times that mimicked the residence time of the supplements in the human body. To test this, we conducted experiments to either provide evidence for our hypothesis or disprove it. The more we understood the biochemistry of each, the more we questioned whether the efficacies of anti-diabetic chromium(III) supplements were associated with the generation of carcinogenic chromium(VI) and chromium(V). Vanadium drugs have been in clinical trials for their anti-diabetic effects that occur via species with very similar chemistry to chromium(VI). Response: My group has been studying the molecular mechanisms of chromium(VI)-induced cancers and the biochemistry of vanadium over the last three decades. Medical Research: What is the background for this study? What are the main findings?

Director, Vibrational Spectroscopy Core Facility

Chromium weight loss study