Thanks Eve, very interesting. I didn't know about J. I. Rodale and it seems GCB doesn't know about him or any previous findings about wheat's harmfulness neither. There was no Internet and information about previous researches were not so easily found in the 60's when he unexpectedly observed these effects of wheat on animals. On top of those you mentioned, comes schizophrenia.
In the late 19th century, there was a surge of so-called new-age thinking about many subjects as many branches of "science" distinguished themselves from "religion." Mind and body were explained by science, and we saw the rise of everything from mesmerism to homeopathy, and there were many branches of science that dealt with nutrition. There was a flourishing interest in nutrition, spurred by discoveries in anatomical science (x-rays, cadaver studies). Even the casualty-ridden US Civil War gave rise to battlefield doctors who poked around in the ruptured bodies of severely wounded soldiers.
That was the era of the Cereal Kings - men like John Harvey Kellogg and Charles Post - who promoted their cereals as cure-alls for ailments. (Good book also made into a movie:
The Road to Wellville gives a hilarious portrayal of a Kellogg-like sanitarium). The premise was that murdered animal flesh was bad for the body and mind, and gentler effects could be had from living on grains. Even wild animals like the tiger were raised in captivity on cereal, supposedly proving that vegetarian eating made ferocious animals docile. (In fact, the animal's docility was due to its meat-deprived, weakened constitution.) This was also the time when Indian ascetics ventured into the west, bringing their karmic blessings to vegetarianism.
Then, as now, great healing could be achieved by a change of diet from indulgent to moderate. You could go "for the cure" and get results if you were formerly nibbling on pastries all day long. Even shredded wheat cereal will heal something if you have been eating your wheat in breads and cakes.
I guess there's nothing new under the sun.