Chromium

Chromium is an essential trace mineral, important in processing carbohydrates and fats, and helping cells respond properly to insulin—the hormone, produced in the pancreas, that makes blood sugar available to the cells as our basic fuel. In theory chromium might promote weight loss, treat diabetes, and perhaps even help prevent heart disease.

Claims, purported benefits: Builds muscle, lowers blood cholesterol, prevents and treats diabetes, promotes weight loss especially in the very overweight, alleviates depression.

Bottom line: So far the most carefully conducted studies on chromium have shown no benefits for weight loss. One large clinical trial conducted in China found that chromium was helpful for those with diabetes—but the Chinese, including those with diabetes, are less likely to be obese than Americans, and their chromium levels were not evaluated at the start of the study. Clinical trials in the U.S. have so far produced no clear evidence of benefits from chromium supplements. Low levels of chromium are characteristic of diabetes, but there’s no evidence of a cause-and-effect relationship, or any reason to think Americans are deficient in chromium.

Laboratory studies have found that chromium picolinate (the most popular form of the supplement) could damage genetic material in animal cells, which suggests it might cause cancer. This is only preliminary evidence, but nobody knows whether chromium picolinate, particularly in large doses over the long term, is safe. There are more reliable ways to prevent and treat diabetes. There is no good evidence backing chromium picolinate for weight loss, building muscles, or reducing blood cholesterol. Nobody should take chromium picolinate, especially not young people.