A daily dose can help you shed pounds, reduce body fat and increase muscle mass--or so proponents say.
No wonder chromium picolinate is hot-hot.
According to the Federal Trade Commission, Americans spend $100 million a year on chromium picolinate-based products with promising names like Metabolift and Chroma-Slim. A bottle of 60 200-microgram tablets, enough for two weeks or more, costs about $4 to $15, depending on whether other ingredients are included.
But not everyone's gung-ho.
Recently, the FTC cracked down on seven companies, telling them that the chromium picolinate-related weight-loss claims must be backed with scientific evidence.
Ever since a university study published in 1989 found that chromium picolinate improved the physique of college students, research has flip-flopped on the supplement's effectiveness.
Then last month, University of Texas researchers reported some surprising findings in the journal Medicine and Science in Sports and Exercise: Women who took the supplement and did not exercise gained weight--and body fat.
Chromium, an essential trace element that plays a role in carbohydrate, fat and protein metabolism, increases the effectiveness of insulin, helping it transfer glucose and other nutrients from the bloodstream to the cells. (Picolinate, an amino acid metabolite, is added to improve absorption.)
The generally recommended daily intake of chromium, about 50 to 200 micrograms, is easily gotten from a healthful diet that includes whole-grain products, cheese, meat and eggs, experts say, and some wonder if extra amounts do any good for weight control.
But the jury's still out, most experts concur, when it comes to chromium picolinate's worth as a weight-control aid.
First came the 1989 study by Gary W. Evans, a chemist and professor at Bemidji State University in Minnesota. He found that 16 students who took a daily dose of 200 micrograms of chromium picolinate and weight-trained for an hour four times a week lost 7 pounds of fat and gained 6 pounds of muscle during the six-week study. The 15 men in the control group who took a daily placebo pill and performed the same workouts lost just 2.2 pounds of fat and gained about 4 pounds of muscle.
After Evans' study was published in the International Journal of Biosocial and Medical Research, others tried to replicate the findings.
Among them: Priscilla Clarkson, associate dean and professor of exercise science at the School of Public Health and Health Sciences at the University of Massachusetts at Amherst. Her research team, funded by the U.S. Olympic Committee, gave the same 200-microgram daily dose to 18 university football players for two months. But they found no change in the subjects' muscle or fat. The study was published in 1994 in the International Journal of Sports Nutrition.
More studies followed, some promising, some not. For instance, researchers from Texas and New Jersey gave 154 moderately overweight men (average weight, 185 pounds) chromium picolinate or a placebo for six weeks, with no advice about diet or exercise. Those in the higher-dose supplement group, taking 400 micrograms daily, lost 4.5 pounds of fat on average, while those in the other group shed less than half a pound of fat, according to a report published last year in the journal Current Therapeutic Research.
Penn State University researchers gave nine middle-aged, sedentary men 924 micrograms a day of the supplement and instructed them to follow a strength-training program during the 12-week study. They gave nine other men placebos and put them on the same exercise regimen.
All subjects reduced body fat and increased muscle mass, but chromium picolinate deserves none of the credit, says researcher Wayne Campbell, now an assistant professor of geriatrics at the University of Arkansas for Medical Sciences, who presented the data at the American College of Sports Medicine meeting earlier this year.
"The persons who took chromium picolinate did not respond in any way differently than those who did not," he says.
Now comes the Texas study. John Ivy, professor and director of the Exercise Physiology and Metabolism Laboratory at the University of Texas, Austin, and his team studied 43 overweight women, 18 to 35, for nine weeks. Those who took 400 micrograms of chromium picolinate daily but did not exercise gained about 4 pounds, half of it body fat, while those who exercised and took the supplement lost on average just a quarter pound. Those who exercised and took placebo pills gained about 1.5 pounds--although they reduced their body fat slightly.
Those who exercised and took another form of the supplement, chromium nicotinate, lost about 2.5 pounds and reduced body fat slightly. (Nicotinate is a form of the B vitamin niacin and is unrelated to nicotine.) But further study is needed before people jump on the chromium nicotinate bandwagon, says Ivy, whose study was supported by a grant from Shaklee Inc., a San Francisco nutritional supplement manufacturer that markets some products with chromium nicotinate.
A co-researcher, Arthur Castle, now a postdoctoral fellow at the National Institutes of Health, agrees that more research is needed, but says that their study, while small, suggests that "taking chromium picolinate without exercising could make it easier for your body to store fat."
But Victor Moreno, president of Nutrition 21 in San Diego, the sole U.S. supplier of chromium, contends that many studies are simply too brief. The benefits of the supplement can take 12 weeks or longer to kick in, says Moreno, who holds a doctorate in food science and biochemistry. He cites research, also presented at the American College of Sports Medicine meeting, in which swim team members' body composition did not change until Week 12.
"It may be that more time is needed," Clarkson concedes. For now, though, she says of the supplement: "There's not sufficient data to show it works for losing fat or gaining muscle."
In one area, the research of chromium picolinate is less murky. Several studies have found that extra chromium might help ward off diabetes later in life in people prone to the disease.
"For the millions of Americans who are on their way to diabetes, extra chromium could hold out a glimmer of hope," says David Schardt of the Center for Science in the Public Interest in Washington, D.C. Still, the group gives the supplement a thumbs-down for weight control.
In one small study on animal cell cultures, the supplement increased damage that could lead to cancer risk in humans, says Diane Stearns, an assistant professor of chemistry at Northern Arizona University, Flagstaff. She did the study while at Dartmouth College, and her conclusions, published in the Federation of American Societies for Experimental Biology journal, were widely criticized.
Even so, she is continuing the research and hopes to have more findings next year.