Chromium, a trace mineral essential for proper insulin function and proper metabolism of carbohydrate, fat and protein, occurs naturally in foods in small amounts but is not well absorbed by the body.
Chromium picolinate has been used as a dietary supplement ingredient in the US for more than a decade, and a recent study presented at Experimental Biology in March showed chromium picolinate to be the most bioavailable compound.
Carried out at the request of the UK's Food Standards Agency at Environ Health Sciences Institute, the new study is a repeat of earlier published research which did indeed suggest that chromium picolinate was responsible for DNA damage. However this prior study was conducted using chromium picolinate produced by the testing laboratory and not commercially available. Furthermore, it used a procedure that did not meet International Conference on Harmonization (ICH) guidelines - a 48 hour exposure period.
"When Chromax was tested using internationally accepted guidelines, there was no damage to DNA resulting in gene mutations, even at doses higher than those used in earlier studies," said lead researcher Dr Ron Slesinski, president of the regulatory & safety specialty section of the Society of Toxicology.
In his study using Chromax, Slesinski measured metabolic activation with a five-hour exposure (in accordance with ICH guidelines), and also repeated the test with a 48-hour exposure period.
First, the chromium picolinate was suspended in dimethyl sulfoxide up to a concentration of 50 mg/mL. Exposures to the cells were conducted both under conditions in which precipitate of chromium picolinate was not evident and under conditions in which some precipitate was visually evident in the cell culture medium at the highest concentration (500 ìg/mL). The lowest concentrations evaluated for mutagenicity ranged was 15.6 ìg/mL for the five-hour exposure and 31.3 ìg/mL for the 48-hour exposure.
The results, to be published in an upcoming issue of Mutation Research Genetic Toxicology and Environmental Mutagenesis and currently available online, showed that only a slight degree of cytotoxicity was seen in the standard tests up to the limit of solubility in the medium. Toxicity was observed at 500 ìg/mL following a 48-hour exposure period, but no mutagenic increases.
"The new findings are consistent with many previous studies showing chromium picolinate is safe," said Slesinski.
In excess of 50 scientific studies exist supporting the safety of chromium picolinate, including human clinical trials involving 2,000+ participants.
But James Komorowski, VP of technical services and scientific affairs at Nutrition 21 said that the outcome of this study in particular was critical to the FSA's decision to allow Chromax to continue to be sold in the UK.
At the beginning of last year Nutrition 21 filed a health claim petition with the FDA linking chromium picolinate with a reduced risk of insulin resistance, type 2 diabetes and related disease, but last week the company announced it had agreed to grant the government agency another 60 days to review the evidence.