Some writers claim that protein is protein, be it animal or plant, except for the way that animals are treated. How do you respond to this?
We have information that the primary difference between animal and plant proteins is their amino acid profiles and it is those profiles that direct the rates at which the absorbed amino acids are put to use within the body. Animal based proteins, of course, are much more similar to our proteins, thus are used more readily and rapidly than plant proteins. That is, ‘substrate’ amino acids derived from animal based proteins are more readily available for our own protein synthesizing reactions which allows them to operate at full tilt. Plant proteins are somewhat compromised by their limitation of one or more amino acids. When we restore the relatively deficient amino acid in a plant protein, we get a response rate equivalent to animal proteins. My own lab produced experimental data to support this view–and of course, similar observations of years past in other laboratories can also be interpreted in this way.
Some of the profile differences between animal and plant proteins have been previously noted by the ratios of arginine to lysine which are predictive, in turn, of tissue responses.
Animal proteins also have a higher concentration of sulphur containing amino acids that get metabolized to acid-generating metabolites. As a result, a slightly lower physiological pH must be corrected and buffers like calcium are used to attenuate these adverse acid effects–to the disadvantage of the host.
But my main thesis, insofar as my own work is concerned, is that our observations on protein and cancer, although studied in considerable detail, were signals of hypotheses that were more important and more global. [...]