Experimental rickets : the effect of cereals and their interaction with other factors of diet and environment in producing rickets / by Edward Mellanby.

Edward Mellanby

Date:: 1925

Credit: Experimental rickets : the effect of cereals and their interaction with other factors of diet and environment in producing rickets / by Edward Mellanby. Source: Wellcome Collection.

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$closely allied dietetic conditions. Evidence for the presence of a constituent of germ partially removed by ether extraction, and capable of acting on the nervous system and especially of bringing about loss of balance, is fairly strong in these experiments, but is not conclusive. If this substance is also present in other cereals, it must be in smaller amounts than in wheat germ. On the other hand, the substance in oatmeal which interferes so strongly with bone-calcification is present in smaller amounts in wheat germ. It would be interesting if it should prove that the different effects of toxic action produced by oatmeal and wheat germ, when forming large parts of diets deficient in anti-rachitic vitamin, should depend on different substances both of which are associated with the fatty acid fraction. t The rickets-producing effect of cereals has now been considered from different points of view, and, although the experimental evidence described above is of a preliminary nature, it suggests that two factors, at least, are responsible for the effect. One of these is the part of the grain which allows increased growth. The second is probably some chemical constituent which interferes with the calcification of the growing bone. As regards the first of these, although to the carbohydrate content of cereals must be apportioned some part of the responsibility for growth, the protein present in them must also be considered as of importance in this connexion. If cereals contained some factors which hastened calcification processes in bone, in addition to those substances which are incorporated in the growing organism, normal bone tissue might still be laid down under their influence. Unfortunately, not only do they not appear to contain a substance of this nature of any potency, but, in the one cereal more closely examined, namely oatmeal, there is evidence of a chemical body which actively interferes with the mechanism for laying down calcium salts in the bones. A substance with this property may also be present in wheat germ and in other cereals, but the evidence of this is at present smaller, and in any case its activity is much less apparent in the amounts used than that of the same factor in oatmeal. It is too early to speculate either as to the chemical composition of the active substance or as to its mode of action. Even if the results described above showing the interfering effect of the fatty acid content of oatmeal on bone-calcification should prove to bo specific and not simply due to their fatty acid constituents as such, they do not appear to account for the whole oatmeal action. On the other hand, some part of the fatty acid influence may have dis¬ appeared as the result of the drastic chemical treatment which was used in their preparation. As regards the mode of action of the substance, its influence is so diametrically opposed to that of the anti-rachitic vitamin that the possibility of it being an anti-vitamin suggests itself. This, however, is pure speculation. Not only does it interfere with the laying down of calcium in bones and also, as shown by M. Mellanby [44 (a)], in teeth, and thereby act in opposi¬ tion to the anti-rachitic vitamin, but just as the vitamin and ultra-violet radiation assist each other, and are to some extent$