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A BIOLOGICAL ANALYSIS OF PELLAGRA-PRODUCING DIETS

1919; Elsevier BV; Volume: 38; Issue: 1 Linguagem: Inglês

10.1016/s0021-9258(18)87380-x

1083-351X

E. V. McCollum, Nina Simmonds, Helen T. Parsons,

Diet and metabolism studies

Our experimental studies have now progressed so far as to enable us to assert with confidence that a satisfactory diet cannot be secured from mixtures containing any number of seeds or products derived from the milling of seeds together with tubers, edible roots, and meats (Chart 4, Lot 2147).The vegetable foods which may be classed as seeds, tubers, and roots are all functionally storage organs, and their content of active protoplasm is relatively small in comparison with their bulk because of the large amount of reserve food material laid down En them.They may be sharply contrasted with the leaf of the plant, which except in special cases is not a repository for reserve proteins, carbohydrates, and fats, but represents, aside from its skeletal tissues, functionally active protoplasm (9).The leaf has very different dietary properties from those possessed by the tissues which are modified as storage organs, and in many instances at least represents complete foods for those types of animals whose digestive tracts are so capacious as to permit them to eat a sufficient amount of bulky material.As stated above, we'have been able to prepare fairly satisfactory diets for an omnivorous animal, the rat, from these two types of vegetable foods together, i.e., leaves and seeds, but never from the group of vegetable foods which are functionally storage organs (10).From this experience we have been led to differentiate sharply between two classes of foods which are usually collectiveiy designated as vegetables.Leaves are constituted so as to correct the dietary deficiencies of the storage tissues, whereas the seeds, tubers, and roots fail to supplement mutually each other's deficiencies with respect to either the inorganic moiety or the fat-soluble A. They do in some degree mutually enhance the quality of each other's proteins, but to a lesser degree than we had supposed before the completion of a large amount of experimental work directed toward the quantitative comparison of the protein mixtures derived from pairs of seeds in considerable number.Mixtures of seeds, or of seeds, tubers, and roots, will in all cases require supplementing with respect to calcium; sodium, and chlorine among the' inorganic elements, and fat-soluble A (compare Charts 3 and 4 with Chart 5).In most such mixtures the quality of the proteins will likewise be sufhciently poor to require improvement before the optimum well being can be secured.