There are those who believe that the methods of preserving foods, cereal or proteid, by sterilizing at high temperatures, destroy the vitamines so essential to proper metabolism so that people who subsist extensively on canned vegetables and preserved meats, instead of fresh meats and vegetables, may develop pellagra. Evidence of this sort is obtainable in the mill villages of the Southern States of the United States where pellagra is so very prevalent.
We are now beginning to recognize that slight and vague digestive trouble may be pellagrous in nature although never going on to the development of the cutaneous, neurological and alimentary tract diagnostic triad of symptoms.
Again there would appear to be efficient resistance to pellagra in those who are in good physical condition, but when reduced by illness, or the effects of poor diet and defective hygienic surroundings, they may develop it. There are those who think that hookworm disease is an important factor in predisposing to pellagra.
Not only does alcoholism, when coexistent with pellagra, make for a bad prognosis but there are many who think that any abuse of alcohol predisposes to pellagra. Against this however is the fact that pellagra in the United States is about five times as common among women as among men. It is generally recognized that pregnancy and lactation predispose to pellagra.
Pellagra in Turkish and German Prisoners.—There were (up to the close of 1919) 9257 cases of pellagra among 105,668 Turkish prisoners (1 in 11) and 79 cases among 7606 German prisoners (1 in 96). The Turkish prisoners had been on a deficient diet before capture and the diet after capture had a B. P. V. of 33.5. The labour group of the prisoners had a B. P. V. of 36.8 and the disease was much more prevalent among them than in those not working. Hammond-Searle notes that the diet of the nonworking European prisoners was probably insufficient to prevent pellagra. On the average the disease appeared among the German prisoners 4½ months after capture. They stated that while in Turkey their diet had been excellent but almost all had suffered from dysentery or malaria. In the Turkish prisoners diarrhoea was a prominent feature and Bigland suggests a possible toxin action resulting from a damaged intestinal mucosa. Stools from pellagrous Turkish prisoners showed organisms similar to B. perfringens in 90% of cases while such organisms were not found in the stools of healthy prisoners.
The Zeistic Views.—The idea which was at one time entertained that maize, whether good or bad, brought on pellagra has now been generally abandoned, owing to investigations, which proved that corn possessed a fair nutritive value and was easily assimilable, together with evidence to show that where care was taken in the maturing of the grain and the prevention of decomposition by moulds or bacteria, pellagra was either nonexistent or diminished in a district where such measures were instituted.
The statement is frequently seen that pellagra did not make its appearance in Europe until after the introduction of maize, subsequent to the discovery of the New World. There are authors who think Casal was suspicious of a maize dietary.
The zeistic views now incorporate some additional factor with the basic one of a rather exclusive maize dietary.
1. The verderame theory of Ballardini. From noting on the corn grains a covering with a greenish mould, Ballardini in 1845 advanced the view that pellagra was due to this mould and from this time on we have the so-called zeitoxic views, which hold that pellagra is caused by spoiled corn. Ceni and Fossati regard a toxin elaborated by various moulds as causative. The fungi toward which attention has been chiefly directed are Aspergillus fumigatus and A. flavescens as well as certain species of Penicillium and Mucor.
2. The Lombroso view that as a result of the action of moulds or bacteria, toxins are elaborated which, when ingested, give rise to the disease.