It's not clear if the findings will translate into harm in people, but they raise the possibility that the controversial supplement may cause cancer. However, a doctor who represents the supplement industry says the study is "very bad science" because it didn't use live animals and relied on unreasonably high amounts of chromium picolinate.
"No one's going to be taking those kinds of doses," says Dr. Mark Houston, a professor at Vanderbilt University and editor-in-chief of the Journal of the American Nutraceutical Association. "This study is interesting only if we are test tubes, not biological beings, and we were given toxic doses of chromium."Chromium picolinate can be found in nearly any health food store or on vitamin shelves at pharmacies. It first became popular in the 1980s as a dietary supplement that supposedly helped the body build muscle. It is still sold for that purpose, although some proponents and critics now agree that its worth as a fitness booster has not been proven.
In recent years, diabetics have begun taking chromium picolinate because it may help the body do a better job of metabolizing blood sugar, known as glucose. People who have Type II diabetes, the most common type, lose the ability to regulate their blood sugar properly and face health problems when glucose levels rise too high.
Some supplement experts think chromium picolinate also may help treat obesity.
In 1995, researchers at Dartmouth College discovered that chromium picolinate may cause damage to chromosomes in hamsters, suggesting that the supplement could cause cancer in humans. Diana Stearns, one of the researchers, moved on to a job as an assistant professor of biochemistry at Northern Arizona University and continued studying the interaction between the supplement and hamster cells.
In her new study, Stearns grew hamster cells in the laboratory and examined them after they were exposed to chromium picolinate. Her findings will appear in the Jan. 15 issue of the journal Mutation Research.
Stearns found potentially dangerous mutations in the cells, suggesting that future generations of the cells would be affected.
While the amounts of chromium picolinate in the hamster cells are not comparable to what humans would typically consume, they are within general guidelines for testing whether substances are hazardous, Stearns says.
The tests don't allow researchers to definitively say that chromium picolinate causes cancer, she says. Instead, "it allows us to say it is possible."
Chromium picolinate is a metal, and other metals, including arsenic, cadmium and nickel, are definitely hazardous to humans, Stearns says.
However, human bodies need trace amounts of chromium and other metals, like iron, manganese, zinc and copper.
Stearns says scientists need to study the toxicity of large amounts of a substance to determine if they need to look at small amounts.
But Houston, the journal editor and university professor, says the study is unrealistic and doesn't predict what would happen in a live animal.
Chromium picolinate doesn't have side effects if used in proper doses for treatment of diabetes or obesity, says Houston, who also is a spokesman for the American Nutraceutical Association. "Nutraceutical" refers to products, like vitamins, that claim to improve health or well-being.
Stearns says she's not willing to advise people on whether to take chromium picolinate, although she wouldn't herself. "I just want them to be aware of the science and what they're putting into their bodies," she says.
What To Do: This article in the Berkeley Wellness Letter advises against taking chromium picolinate without medical advice. For information about supplements from an industry standpoint, visit the