The athlete's toolbox is taking another hit with a new study suggesting that chromium picolinate, a popular supplement perceived to trim fat and build muscle, could cause sterility in a user's children and grandchildren.

The supplement industry denounced the findings of University of Alabama researchers that will be published Tuesday in a scientific journal, arguing that test results on fruit flies cannot be used to project what might happen to human beings.

But coming in the wake of a medical examiner's report that listed another dietary supplement, ephedra, as a contributing factor in the death of Baltimore Orioles pitcher Steve Bechler, the Alabama study is sure to raise even further concerns about over-the-counter products used by athletes.

"It's just another example that there's no free lunch when it comes to using these supplements," said Frank Uryasz, director of the National Center for Drug Free Sport, which runs the NCAA's drug-testing program.

Chromium picolinate, widely available in stores and over the Internet, is sold in forms that include pills and sports drinks. The substance became popular among bodybuilders and athletes about a decade ago, with sales now exceeding $87 million a year, according to the Nutrition Business Journal.

The Federal Trade Commission in 1996 cracked down on companies marketing chromium picolinate as a muscle-building substance due to studies that show otherwise. But its early reputation remains intact, as manufacturers often combine it with other products that have demonstrated anabolic effects.

Unlike ephedra, chromium picolinate is not banned for use by athletes competing in the NCAA or Olympics, among other leagues.

"I'm sure the NCAA will look at this study very closely," Uryasz said. "If the NCAA finds that it is harmful to athletes, it probably will ban it."

Like Uryasz, Richard Pound, head of the World Anti-Doping Agency that is taking over drug testing for the Olympics, said he had not read the study. He also expressed interest in its findings, saying chromium picolinate could be added to the banned list if it is judged to be "harmful and contrary to the spirit of the sport."

The Alabama study, funded by the American Diabetes Association, will be published Tuesday in the Proceedings of the National Academy of Sciences. ESPN.com received an advance copy of the 29-page study, which notes that fruit flies given chromium picolinate were more likely to produce female offspring that are sterile.

Dr. John Vincent, a chemistry professor at Alabama who led the study, said the substance appears to harm the DNA in future generations. He used flies because their short life spans allow for rapid study and, as a scientific practice, tests on humans often reveal similar results.

"This means there's a very good chance that chromium picolinate could cause a similar change in humans who take it," Vincent said. "We gave it to rats earlier this year, and saw damage to that animal as well."

The Council for Responsible Nutrition, a trade group for the supplement industry, issued a press release that discounted the Alabama findings. In an interview with ESPN.com, an official for the group said other studies suggest chromium picolinate is safe for human use.

"If this study was all we knew about it, they might have something (damning)," said Dr. John Hathcock, a CRN vice president. "But this isn't all we have."

The question of whether human DNA in subsequent generations is harmed by chromium picolinate has never been studied -- and probably won't be, Hathcock said, given the 60 years it would take to conduct the same three-generation test on fruit flies. But studies have yet to show damage to the DNA of a current user, he said.

Henry Lukaski, a lead researcher at the U.S. Department of Agriculture who has read the Alabama report, said more study is needed before assuming that humans will be harmed. But Lukaski praised the credentials of Vincent, who has previous experience studying chromium picolinate, and said the findings "raise a red flag" for athletes.

"People probably should be cautious in general about using chromium picolinate," Lukaski said.

Tom Farrey is a senior writer with ESPN.com. He can be reached at tom.farrey@espn3.com.