Potential health benefits of chromium supplementation

Trivalent chromium, (Cr(III)), has been used for over 50 years as a “micronutrient”. However, chromium has been shown not to be an essential element. The four studies conducted for this dissertation research attempt to better illuminate how Cr(III) functions in the body. Chapter 2 explores chromium effects on colorectal cancer. In order to explore this link, the effects of Cr(III) compounds were investigated in male and female FVB/NJ mice with azoxymethane-induced colorectal cancer. Cr(III) was found to not have a significant beneficial effect on azoxymethane-induced colorectal cancer. Glucocorticoids, such as dexamethasone, are anti-inflammatory drugs that treat conditions such as arthritis. However, over time the constant use of these drugs impairs wound healing. Cr(III) has been proposed to enhance levels of insulin like growth factor 1 (IGF-1) and increase wound healing. Chapter 3 explores the ability of various Cr(III) compounds to enhance wound healing in C57BL6/JNarl mice receiving dexamethasone. Wound recovery rates, morphological differences and amount of IGF-1 present were determined. Cr(III) was found to not significantly enhance wound healing rates or IGF-1 levels. Bitter melon (BM) has been used in Asia and some parts of Africa as a prophylactic against diabetes. Although research has shown that bitter melon may reduce the effects of diabetes, the exact mechanism, as the case of Cr(III), is unknown. Chapter 4 explores the effects of chromium and bitter melon in insulin-resistant and type 2 diabetic Sprague Dawley rats. The combination of BM and Cr had no beneficial effects on type 2 diabetes or insulin resistance. However, BM tended to reduce glucose levels but negated effects of Cr(III) on insulin resistance in the diabetic rats. Finally, the effects of chromium supplements on farm animals has drawn considerable attention in the last four decades. Thus, a systematic review of the effects of Cr(III) on chickens was undertaken. With the exception of studies on cold-stressed laying hens, the results of studies of Cr supplementation of chickens, whether laying hens or broilers, are too inconsistent for any conclusions to be drawn other than supplementation with Cr led to the acculmulation of Cr in tissues.