1921] on Quality of Protein in Nutrition 349 



of the whole digestive tract, by skin lesion, usually bilaterally sym- 

 metrical, and often mistaken at first for sunburn or chapping of the 

 hands, face and neck, and other exposed areas. The nervous system 

 is also affected. 



There is no definite record of pellagra in Europe before maize 

 was introduced into Spain by Columbus. From Spain the disease 

 spread to France, Lombardy, and eastwards, wherever maize was 

 extensively used for food in the poorer agricultural districts. The 

 relation of maize to the disease puzzled the medical profession for 

 nearly 200 years, as the disease occurred where maize was not used, 

 and in some districts maize was used, but there was no pellagra. 

 Roussel, in 1866, showed that it could be cured by good food, and 

 Lorentz (1914) and Willets (1915) successfully treated advanced 

 cases with a generous diet. Goldberger also cured and prevented the 

 seasonal appearance of pellagra in lunatic asylums and orphanages 

 by increasing the quantity of meat and milk ; previously the diet bad 

 been deficient in this respect. 



Goldberger, by the offer of a free pardon from the Governor of 

 Mississippi, was enabled to obtain eleven convicts as volunteers for 

 a feeding experiment to determine if pellagra could be produced by 

 an unbalanced diet in healthy white men. The " pellagra squad," as 

 they were called, were fed on white wheat flour, various maize pre- 

 parations, polished rice, sugar, sweet potatoes, pork fat, cabbage and 

 turnip tops. The food had an energy value of 2950 calories, and 

 was amply sufficient in this respect. After the second month on 

 this diet the men complained of weakness, headache, abdominal pain 

 and other minor discomforts. After five months six developed a 

 rash, which was pronounced by experts to be identical with that seen 

 in pellagra. During the last four weeks all the prisoners had shown 

 marked loss of weight, and were much out of health. Pellagra would 

 probably have developed in the remainder, but the experiment had 

 to be abandoned owing to the refusal of the men to continue. A 

 control was carried out at the same time ; their diet contained some 

 meat, eggs and butter-milk ; there was not a single case of pellagra, 

 and no progressive loss of body weight. 



These and other facts clearly point to the diet as the controlling 

 factor in the cause and prevention of the disease. The determining 

 factor seems to be the quality of the proteins. Good evidence on 

 this point has been furnished by Wilson, of Cairo. In 1916 pellagra 

 broke out in a camp for Armeniau refugees at Port Said. Wilson 

 showed that the diet at first supplied was inadequate both in energy 

 supply (2200 calories) and in protein supply ; 92 per cent of the 

 protein was of vegetable origin, three quarters from wheat, and one 

 quarter from maize. 



By determining the nitrogen balance in man on various proteins, 

 Thomas has demonstrated that proteins have very different biological 

 values. He assigned a set of comparative values according to the 



2 b 2 



