Chromium & Disease Prevention

Impaired glucose tolerance and type 2 (non-insulin dependent) diabetes

In 12 out of 15 controlled studies of people with impaired glucose tolerance, chromium supplementation was found to improve some measure of glucose utilization or to have beneficial effects on blood lipid profiles. Impaired glucose tolerance refers to a metabolic state between normal glucose regulation and overt diabetes. Generally, blood glucose levels are higher than normal, but lower than those accepted as diagnostic for diabetes. Impaired glucose tolerance is associated with increased risk for cardiovascular diseases but is not associated with the other classic complications of diabetes. About 25% to 30% of individuals with impaired glucose tolerance eventually develop type 2 diabetes. Generally, chromium supplementation at doses of about 200 mcg/day, in a variety of forms for two to three months were found to be beneficial. The reasons for the variation or lack of effect in some studies are not clear, but chromium depletion is not the only known cause of impaired glucose tolerance. Additionally, the lack of an accurate measure of chromium nutritional status prevents researchers from identifying those individuals who are most likely to benefit from chromium supplementation.

Cardiovascular diseases

Impaired glucose tolerance and type 2 diabetes are associated with adverse changes in lipid profiles and increased risk of cardiovascular diseases. Studies examining the effects of chromium supplementation on lipid profiles have been notable for their inconsistent results. While some studies have observed reductions in serum total cholesterol, LDL-cholesterol, and triglyceride levels or increases in HDL-cholesterol levels, others have observed no effect. Such inconsistent responses of lipid and lipoprotein levels to chromium supplementation may reflect differences in chromium nutritional status. It is possible that only those individuals with insufficient chromium will experience beneficial effects on lipid profiles due to chromium supplementation.

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