IT’S RENOWNED for helping slim the figure, but this dietary supplement could be killing you.
Chromium is an ingredient in many off-the-shelf supplements marketed for weight loss and blood sugar control, helping consumers to shift excess flab, and manage insulin resistance and type 2 diabetes. It’s in the vast majority of multivitamins on the market.
But Australian scientists say they have conclusive proof that it is converted by the body into a cancer-causing chemical, with their findings recently published in the chemistry journal Angewandte Chemie.
The study, led by the universities of Sydney and NSW, has shown that living cells convert chromium III into its “carcinogenic cousin”, hexavalent chromium.
Remember Erin Brokovich, starring Julia Roberts as law clerk-turned-ecowarrior?
Hexavalent chromium is the deadly chemical she discovered was contaminating the groundwater in her Californian town, where residents were developing cancerous tumours at a disturbing rate.
The research team injected chromium III into animal fat cells in the laboratory, then mapped the chemical elements within them under an intense X-ray beam at a synchrotron facility.
This allowed them to not only see the chromium spots throughout the cell but also to determine whether they were the carcinogenic form.
“We were able to show that oxidation of chromium inside the cell does occur, as it loses electrons and transforms into a carcinogenic form,” UNSW’s Dr Lindsay Wu said.
“It’s the first time anyone’s seen it in a cell.”
He said more research was needed to ascertain whether the supplements significantly alter cancer risk, but that the findings should raise a red flag for anyone taking chromium pills long-term or in high doses.
Only time will tell whether it is taking a deadly toll — it takes decades for tumours to develop as a result of exposure to the chemical.
Chromium is a trace mineral sold as nutritional supplements, with some containing up to 500 micrograms per tablet.
Experts say that the only people who need chromium supplements are those with a deficiency, advising against using it as a weight loss tool.
Australia’s current National Health and Medical Research Council Nutrient Reference Values, which are under review, recommend 25-35 micrograms of chromium daily as an adequate adult intake, but multivitamins can contain more than five times that amount.
Australian vitamins company Blackmores sells supplements containing chromium III, and its researchers maintain that it is beneficial.
A Blackmores Institute spokeswoman said chromium III’s safety was supported by European Food Standards Authority and World Health Organisation evaluations.
“This study makes no meaningful contribution,” the spokeswoman told The Australian.
“Other published studies show that chromium does not easily transfer into cells, and instead is stored or excreted.”