The use of glandulars dates back many decades. The issue of mad cow disease ( BSE) is a reccent phenonoma. The incubation period of this disease is long, often time many years, up to 30 years. The epideological evidence seems to point to significan exposure appears to pre-date 1985. The prion are infectious proteins that cause both, bSE and cCJD. cCJD is the human version of mad cow disease.
I know a lot of people take glandulars and has for a long time without any problem. I am not trying to ring a false alarm bell here. I think given the onset of mad cow disease discovery that one should be careful in one's choices.