Study: Only High Doses of Chromium Offer Benefits

TUSCALOOSA, Ala.Rats supplemented with chromium equivalent to a human taking a standard nutritional supplement experienced no health benefits compared to rats fed a minimal amount of the mineral in a recent study published in the Journal of Biological Inorganic Chemistry (DOI: 10.1007/s00775-010-0734-y).However, researchers found chromium showed the potential to have a therapeutic effect on diabetes when consumed in large doses.

In the U.S. Department of Agriculture-funded study, the researchers from the University of Alabama fed one group of rats a purified diet containing as little chromium (III) as practically possible for six months while closely monitoring the rats health through various measurements including blood tests. In other rats, the researchers added varying amounts of chromium to the rats diets while monitoring their health.

The diet that had as little chromium (III) as we could put in it and the diet that had an amount corresponding to a human taking a standard nutritional supplement with chromium had no effect on the rats," said Dr. John Vincent, professor of chemistry at University of Alabama and a co-author of the study. They had the same body mass (BMI), they ate the same amount of food, and they were able to metabolize glucose exactly the same. There were no differences in the health of the rats," he said.

Vincent said when they used extremely high doses of chromium," they saw the rats had an increased sensitivity to insulin so their bodies did not have to produce as much insulin to metabolize excess sugar. If you have altered abilities to metabolize lipids and carbohydrates and you take an extremely large dose of chromium, it can lead to improvements at least based on the findings obtained from the animal models," he said.

Vincent said chromium is not an essential element despite the National Academies of Sciences acceptance of it as an essential element in 1980. This means that the status of chromium in numerous nutrition and related textbooks and in the dietary guidelines of the national academies and USDA (and similar agencies) will need to be rewritten."

He added, To be an essential element, you must show that if you take it out of the diet, the subject has adverse health effects; and if you restore it, those effects are reversed. Or, you need to show that it binds to a specific molecule in the body that has a specific function.  The latter has not been done so the findings had previously relied on the nutritional studies."