A dietary supplement developed for use in cattle feed appears to help male athletes build twice as much muscle as exercise alone, Iowa State University scientists reported Monday.
It’s too soon to know all the effects of HMB, which the body naturally produces every time a person eats protein. But clinical trials involving large supplements of HMB are generating excitement among fitness buffs. The supplement’s distributor even claims to have sold it to some Olympians and professional football players.
“If you take HMB and a bag of potato chips and sit on a couch, you’re not going to see any effects,” cautioned Iowa State veterinarian Steven Nissen, who presented his research to biologists meeting here Monday.
But combined with exercise, 3 grams of HMB a day the amount derived if anyone could stand eating 500 grams of meat - helped men develop more muscle and lose more fat, he said.
Is HMB more than just another dietary supplement fad? Time will tell, said Elizabeth Applegate, an expert on such fads at the University of California, Davis, who had not yet seen Nissen’s results.
But she noted that researchers have long touted high-protein diets for athletes, and specifically a protein amino acid called leucine. HMB is a metabolite of leucine.
“We’re becoming more sophisticated” in searching for musclebuilding aids, she said. “First we eat meat, then we take amino acids, now we’re taking metabolites of amino acids.”
HMB appears safe, but needs some more research to prove how it affects muscle, added Rick Sharp, sports medicine director for the U.S. Olympic swimming team, who is following Nissen’s research to determine whether to recommend that his athletes take HMB.
Nissen discovered HMB, known chemically as beta-hydroxy methylbutyrate, in 1988 while searching for ways to grow leaner cattle. Too much leucine was required to make supplements feasible, so he looked at leucine’s byproducts. HMB apparently is the metabolite responsible for leucine’s muscle-building effects, he said.