have a reduced immune function. The research that has shown glutamine supplementation to be effective has been under circumstances where the glutamine is protective against the consequences of reduced immune function, like preventing bacterial translocation across the gut and those sorts of things.
Now, the link [between the immune system and physical activity] would be the problems promoted by leakage of muscle enzymes as a consequence of large amounts of physical activity, which promote an acute phase response, coupled with loss of muscle glutamine and the consequences of that loss.
And so, if you need to think about whether glutamine supplementation would be important in those circumstances, although we think of muscle as the main store of glutamine, you actually have to think of the function of glutamine, which is really on the gut and on the immune function. Thus, unless you actually think about the whole picture, I think you are going to miss some of the outcomes. That is why, ultimately, the studies that must be done must define as many different parameters as possible in terms of performance and include those parameters. So far, we have attacked little bits of the problem with individual studies, and that is why I think it is so hard to put the whole lot together and come up with a sensible answer.
ROBERT NESHEIM: I think that brings us to the next set of presentations, which have to do with cognitive performance, stress, and brain function.