Chromium Therapy For Diabetics Is Risky

Type 2 diabetics who take chromium supplements to increase the sensitivity of their cells to insulin may want to rethink the practice. A study has found that in cells the Cr(III) in the compounds is oxidized to Cr(V) and Cr(VI), forms of chromium that are known to be toxic (Angew. Chem. Int. Ed. 2016, DOI:10.1002/anie.201509065). Researchers led by Peter A. Lay of the University of Sydney previously proposed that Cr(III) supplements enhance insulin sensitivity in diabetics because the chromium is oxidized, but they had not proven that the problematic forms were found in cells. Working in mice adipose cells treated with Cr(III), Lay’s team used microfocus X-ray absorption near-edge structure, or μ-XANES, analysis to show that Cr(III), Cr(V), and Cr(VI) were all unambiguously present in the cells. They propose that the unfortunate oxidation can take place in a cell’s mostly reducing environment because cell signaling pathways, including those involved in insulin processing, often use hydrogen peroxide, a strong oxidizer. “In light of these findings, there is a need for epidemiological studies to ascertain whether Cr(III) supplements alter cancer risk,” the researchers note.