Long-Term Exposure to [Cr 3 O(O 2 CCH 2 CH 3 ) 6 (H 2 O) 3 ] + in Wistar Rats Fed Normal or High-Fat Diets Does Not Alter Glucose Metabolism

The essentiality of chromium(III) has been the subject of much debate, particularly in healthy subjects. Chromium(III)-containing supplements are widely used for body mass loss, building of lean muscle mass, and improving glucose and lipid metabolism. [Cr3O(O2CCH2CH3)6(H2O)3]+, Cr3, is one of the most-studied chromium nutritional supplements. The current study evaluates the effects of long-term (15 months) supplementation with Cr3 on body mass and glucose metabolism in Wistar rats on traditional and cafeteria-style (high fat, high carbohydrate) diets. Male Wistar rats were randomly assigned to one of four treatment groups: (1) control diet (milled Harlan Teklad LM-485 rodent diet), (2) control diet + 1 mg Cr3/kg body mass/day, (3) a cafeteria-style (CAF) diet (high fat, high carbohydrate), or (4) CAF diet + 1 mg Cr3/kg/day. Cr3 supplementation had no effect on fasting blood glucose levels or blood glucose levels in response to glucose and insulin challenges. Rats consuming the CAF + Cr3 diet tended to have a significantly higher body mass than rats consuming the CAF diet, but necropsy results showed no difference in visceral fat or body wall thickness between groups. These data suggest that long-term Cr3 supplementation does not significantly affect body mass in rats consuming a normal diet or glucose levels or metabolism in rats consuming either diet.