So What is Soy Protein Isolate Safe For?

When the Federation of American Societies for Experimental Biology (FASEB) undertook the evaluation of the health aspects of soy protein isolates as feed ingredients, they found that the only safe use for them were as cardboard packaging sealers.  The preamble to the evaluation (SCOGS-101) said:

"The Federation of American Societies for Experimental Biology recognises that the safety of GRAS substances is of National significance, and the Federation resources are particularly suited to marshalling the opinions of knowledgeable scientists....

...These scientists were chosen for their experience and judgement with due consideration for balance and breadth."

With all that breadth, they decided that the only satisfactory use for soy protein was as a cardboard sealer, and that was because not enough carcinogen would leach into the contents to pose a health hazard.

In those days, per capita consumption was stated to be less than one third of a gram per person per day, and even at that level, soy protein by clear implication posed a health hazard.