How does HMB work?
Steven Nissen and his colleagues have performed the only study to date of HMB on humans. The researchers agree that the mechanism by which HMB impacts muscle proteolysis and function is not currently known. Nevertheless there are a number of postulations. “The high substrate concentration required by the dioxygenase enzyme compared with the liver concentration of KIC suggests that HMB production in the body may be a first-order reaction controlled by enzyme and KIC concentrations. It has been calculated that, under normal conditions, about 5% of leucine oxidation proceeds via this pathway. Therefore, if humans are assumed to have enzyme actions similar to those seen in pigs, a 70-kg human would produce from .2 to .4 g HMB/day depending on the level of dietary leucine. At leucine intakes of 20-50 g/day (which are used therapeutically), the concentrations of leucine and KIC in the liver increase and could result in HMB production reaching gram quantities per day”(Nissen p.2095). Some stu
