Chromium Picolinate Supplementation And Glycogen Metabolism
By Admin | Thursday, August 28, 2008 12:00:00 AM America/New_York
Chromium is an essential trace mineral that has received much attention as a dietary supplement because good dietary sources are scarce and intake is generally low. Chromium is an essential nutrient meaning your body cannot make chromium. Therefore, dietary intake is necessary. There is debate regarding optimal amounts and exactly how chromium works in the body. Some very elegant work in the last few years has revealed that chromium augments the actions of insulin, and this is consistent with studies showing that long-term use effectively controls blood sugar levels in people with intolerance to carbohydrates. Better control of blood sugar levels has several favorable effects. The exact role of Chromium has eluded researchers, but recent evidence indicates that chromium plays an important role in insulin signaling. Insulin resistance is a prevalent condition that contributes to obesity and several other metabolic problems that predispose people to diabetes and heart disease. Therefore, anything that improves insulin resistance (like exercise) is generally viewed as health promoting. One study showed that rats given additional chromium in their drinking water significantly improved glucose disposal rates and insulin stimulated signaling in skeletal muscle. In other words, the extra chromium improved the insulin resistance normally present in these animals. The findings are consistent with several studies showing improved glucose control in people with glucose intolerance and insulin resistance. Since glycogen synthesis and protein synthesis are regulated by insulin signaling, adding extra chromium could stimulate these processes in individuals who are insulin resistant. My lab recently investigated the potential of chromium picolinate to improve glycogen synthesis after intense exercise in healthy men. Although chromium led to very high rates of glycogen synthesis during recovery from exercise, the values were not significantly different than the placebo group. However, we did find that chromium engaged a different cellular pathway in muscle that bypassed one of the steps that is often deficient in people with glucose intolerance and diabetes. Chromium supplementation is safe with no reported significant side effects. Effective doses seem to be in the range of 200 to 600 micrograms (0.2 to 0.6 mg). There are several types of chromium supplements available, such as chromium chloride, chromium polynicotinate and chromium picolinate. We used chromium picolinate, which is remarkably stable and comparative data show it is the most efficacious form to facilitate glucose control.
Volek JS, Silvestre R, Kirwan JP, Sharman MJ, Judelson DA, Spiering BA, Vingren JL, Maresh CM, Vanheest JL, Kraemer WJ. Effects of chromium supplementation on glycogen synthesis after high-intensity exercise. Med Sci Sports Exerc. 2006 Dec;38(12):2102-9.