A Lecture on THE RELATION OF DIET TO HEALTH AND DISEASE: SOME RECENT INVESTIGATIONS

Abstract

After referring to the work of May Mellanby and C. L. Pattison in demonstrating the calcifying effect on the teeth of vitamin D and the anticalcifying effect of cereal, Mellanby goes on to describe his own results in working out the effects of diet on the central nervous system. Dogs showing severe incoordina-tion of movement, often associated with weakness of the hind legs, and a scattered degeneration of the cord, were found as a rule to have been fed on much cereal, particularly the embryos of the grain; the degenerative changes occurred only in animals receiving a diet poor in fat-soluble vitamins. Since ergot of rye produces degenerative changes in the cord, ergot was used in the diet in an effort to clear up the problem. The degenerative nervous changes in experimental ergotism were found to depend on the absence of a protective diet factor[long dash]not vitamin D, which is present in ergot itself[long dash]but substances rich in vitamin A or a closely associated vitamin, such as egg-yolk, butter, codliver oil, mammalian liver oil and cabbage. This explains why nervous ergotism attacks the poor in times of famine; not only is the rye ergotized, but poverty prevents the use of protective foods such as milk, eggs and green vegetables. It also offers a probable explanation of the apparent capriciousness with which nervous ergotism attacks some members of a family and leaves others untouched; if a person has abundant stores of vitamin A in the liver and other organs, he will not be subject to attack by nervous ergotism until those reserves have been consumed. In studying the effect of grain embryo, it was found possible to produce the nervous degeneration of ergotism from the unergotized rye germ; that is, the nerve toxin present in ergot was present in small and apparently irregular amounts in the normal rye germ; the manifestation of nervous degeneration, however, seems to be in dogs dependent in part on individual susceptibility or resistance. This "toxamin," or toxin which may be antagonized by vitamin, is found in most cereals, most abundantly in the germ, yet present even in white flour, from which the embryo has been removed. The application is suggested of these facts to the study of other conditions characterized by combined subacute degeneration of the cord, such as lathyrism, pellagra and pernicious anemia. H. N. Green and Mellanby had previously reported experimental results on recovery induced by vitamin A from infections in rats. Mellanby here reports favorable results in the arrest of puerperal septicemia by the administration of vitamin A in a small group of clinical cases.