Chromium supplements linked to carcinogens: research
An Australian research team has found concerns with the long-term use of nutritional supplements containing chromium.
UNSW and University of Sydney researchers say chromium partially converts into a carcinogenic form when it enters cells.
The findings are published in the chemistry journal Angewandte Chemie.
There are primarily two forms of chromium: chromium (III) forms such as trivalent chromium (III) picolinate are sold as nutritional supplements. Hexavalent chromium (VI) is its ‘carcinogenic cousin’.
The team was led by Dr Lindsay Wu from UNSW’s School of Medical Sciences and Professor Peter Lay from the University of Sydney’s School of Chemistry. It treated animal fat cells with chromium (III) in a labatory and created a map of every chemical element contained within the cell using a synchrotron’s X-ray beam.
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“The high energy X-ray beam from the synchrotron allowed us to not only see the chromium spots throughout the cell but also to determine whether they were the carcinogenic form,” said Dr Wu.
“We were able to show that oxidation of chromium inside the cell does occur, as it loses electrons and transforms into a carcinogenic form.
“This is the first time this was observed in a biological sample,” Dr Wu said.
Professor Lay said the finding raises concerns over possible cancer causing possibilities of chromium supplements.
“With questionable evidence over the effectiveness of chromium as a dietary supplement, these findings should make people think twice about taking supplements containing large doses of chromium,” Professor Lay said.
“However, additional research is needed to ascertain whether chromium supplements significantly alter cancer risk.”
There is controversy over whether the dietary form of chromium is essential.
Chromium supplements are sometimes used for the treatment of metabolic disorders however they are also commonly used for weight-loss and body building.
Australia’s current National Health and Medical Research Council Nutrient Reference Values, which are currently under review, recommend 25-35 micrograms of chromium daily as an adequate intake for adults.
Trace amounts of chromium (III) can be found in some foods however these findings are unlikely to apply.