Thursday Aug 14, 2014 (foodconsumer.org) -- Chromium VI is known to be toxic.  But a new study suggests that chromium III, which is commonly used in micronutrients/dietary supplements, are genotoxic too.  Previous studies indicate that chromium supplements like chromium picolinbate can cause side effects.

Chinese researchers have found chromium III induces mutations in yeast cells and both cause DNA damage in both yeast cells and Jurkat cells.  And chromium III is even more toxic than chromium VI.

Chromium III and chromium VI render toxicity via different mechanisms.   Specifically, Chromium VI intercalates DNA while chromium III interferes with base pair stacking.

The researchers conclude "Based on our results, we conclude that Cr(III) can directly cause genotoxicity in vivo."

Chromium III is considered an essential element that participates in a number of physiological processes.  It can interact with carbohydrates, iron and vitamin C.  Chromium deficiency is linked to impaired glucose tolerance.  But this study suggests that supplementation with chromium III may not be safe for healthy people while it may help individuals with chromium deficiency. Endurance exercise can promote urinary chromium loss and athletes may benefit from the supplement.

Chromium prevents a number medical conditions including diabetes mellitus or insulin insensitivity, obesity, cardiovascular disease.  This nutrient is known to promote weight loss and increase muscle mass. Chromium is added to supplements indicated for the treatment of diabetes mellitus and obesity.

In any case, high doses of chromium should be avoided because of its potential genotoxicity.  For adult men younger than 51 years, 35 mcg/day is sufficient and for adult men aged 50 years or older, 30 mc/day is recommended.  Women aged younger than 51 years, and 51 years old or older need 25 mcg/day and 20 mcg/day, respectively.

For most healthy individuals, it is best to eat chromium rich foods instead of chromium supplements like chromium picolinate.  Foods high in chromium include broccoli, green beans, potatoes, grapes, oranges, apple with peel and banana.  (Davi dLiu, PHD)

Fang Z, Zhao M, Zhen H, Chen L, Shi P, Huang Z.  Genotoxicity of Tri- and Hexavalent Chromium Compounds In Vivo and Their Modes of Action on DNA Damage In Vitro.  PLoS One. 2014 Aug 11;9(8):e103194.