MACKENZIE WALSER: I do not know the answer to your question. That is the straight answer.
ROBERT NESHEIM: Johanna?
JOHANNA DWYER: This was wonderful. With respect to the Brenner Hypothesis (Brenner et al, 1982) and later work that suggested maybe there was an energy deficit in the subjects on a low protein diet, how strong is the evidence?
MACKENZIE WALSER: Yes. Well, the progressive renal damage, according to Tap et al. (1989), is attributable to calories and not protein. That is right.
JOHANNA DWYER: Yes. If it is attributable to calories and not protein, but the reality of many patients with renal disease is that their energy intakes are also extremely low, do you think the Brenner hypothesis still has relevance to the human situation?
MACKENZIE WALSER: I think that it certainly must have relevance. I should add that those observations stimulated a great deal of research in this field without which the research never would have been done. Exactly where it fits in I am not sure.
For example, people born with one kidney or a small kidney, people with renal hypogenesis, do occasionally develop renal failure. So I am sure that there are instances in which renal failure results from partial nephrectomy or absence thereof and that probably could be ameliorated by protein restriction.
ROBERT NESHEIM: Thank you. We need to move on. It is time for a break here.