|Bryden, Noella - Noel|
Submitted to: Biological Trace Element Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/14/2004
Publication Date: 8/1/2004
Citation: Anderson, R.A., Polansky, M.M. and Bryden, N.A. 2004. Stability and absorption of chromium and absorption of chromium histidinate complexes by humans. Biological Trace Elements Research. 101:211-218. Interpretive Summary: Chromium is an essential nutrient required for normal sugar and fat metabolism. Several well controlled studies have demonstrated that people may benefit from increased intake of supplemental chromium. In this study we demonstrated that not only the form of chromium was important, but also the other components added to the chromium capsules. Three forms of chromium that were shown to be absorbed alone were not absorbed at the levels tested, when added to a chromium capsule containing starch. Starch had been shown from animal studies to increase chromium absorption, when it was added to the diet. Several forms of chromium were tested for their absorption by human subjects, and complexes containing chromium and histidine were shown not only to be absorbed the best, but were also stable and suitable to be used as nutrient supplements. These results will be of benefit to the millions of people who want to improve their intake of chromium, and may also be beneficial in the alleviation of glucose intolerance and diabetes which are increasing each year throughout the world.
Technical Abstract: Increased intake of chromium has been shown to lead to improvements in glucose, insulin, lipids, and related variables in studies involving humans, experimental and farm animals. However, the results are often variable depending not only upon the selection of subjects, but also dietary conditions and form of supplemental Cr used. We determined the absorption of four forms of Cr in 57 subjects with type 2 diabetes mellitus. Subjects sere divided randomly into 4 groups and given 200 ug of Cr/d as Cr chloride, Cr nicotinate, Cr nicotinate-glycine-cysteine-glutamic acid or Cr picolinate for three months in capsules containing a starch filler. Chromium absorption, based upon urinary Cr losses, was similar during the placebo and Cr-supplemented periods for all but the subjects receiving the Cr picolinate. We have subsequently shown that the forms of Cr that were not absorbed were unstable, and were converted to an inert form within one month of being mixed with starch in preparing the Cr capsules. We synthesized a Cr trihistidine complex that is water soluble, stable and absorbed better than Cr picolinate, the supplemental form most often used. Urinary Cr losses for 6 subjects consuming 200 ug of Cr as Cr histidine increased from basal levels of 256 +/- 48 to 3670 +/- 33e ng/d compared with 2082 +/- 201 ng for Cr picolinate in the 48 hours following Cr consumption. Absorption of the Cr-histidine complex was similar to the initial values after more than two years. In summary, chromium histidine is absorbed better than any of the Cr complexes currently available, and may be used to improve Cr nutrition.