T.Izod Bennett, E.C. Dodds
1922 The Lancet  
who have studied the biological values of different s kinds of proteins have indeed given us substantial t grounds for believing that the vegetable proteins are, t in this respect, greatly inferior to animal proteins. c Thomas has arranged the following proteins in a descending scale of value, the protein of beef being E 104, that of milk 100, that of rice 8R, that of potato 79, < that of pulses 59, that of wheat 39, and that of maize ( 29. If, therefore, vegetable proteins are substituted 1
more » ... re substituted 1 for animal or other proteins, they must be given in t relatively greater amount if they are to be equally I available for nutritious purposes ; but no one, as far as I am aware, has ever suggested that the protein of 1 breast milk has three times the biological value of 1 cow's milk as a food for infants. 4 The great difference between the proteins of cow's i milk and of human milk, apart from the relative proportions of caseinogen and whey proteins present ' in each, relates to the inferior digestibility of the former ; but if an infant is incapable of digesting a i small amount of the protein of cow's milk, it is hardly rational to expect that by increasing -the amount the capacity to digest can be improved. The great disadvantage of cow's milk is that it is more refractory to digestion and consequently more liable to bacterial decomposition in the colon, the results of which are included in conditions of intestinal intoxication, quite apart from recognisable symptoms of indigestion. These are the really serious results of protein excess of which Dr. Carter confesses himself ignorant, but in addition to these there are all the later and deferred effects due to the strains of de-amination imposed on the liver by the excessive absorption of normally digested amino-acids, and on the renal function owing to the excessive elimination of the products of nitrogenous metabolism. Every physiologist knows that, apart from its uses for growth, repair, the elaboration of antibodies and the formation of secretions, nitrogenous food is, in a biological sense, a wasteful and expensive source of energy, and therefore should not be employed to replace the cheaper food elements-carbohydrates and fats. I claim that it is unsound to attempt to supply protein in much greater relative amount than it is supplied by nature in breast milk, that is to say, the ratio of protein to the combined carbohydrate and fat in an artificial food should not greatly exceed that of 15 to 10'5. In my formula to which Dr. Carter takes exception I have made a correction for possible biological inferiority by giving 25 per cent. more protein than is actually present in breast milk, and, in spite of the admittedly important support he finds in Dr. Holt's published statements, I still adhere to my original view that " no matter how accurately a diet may comply with -the caloric requirements, nevertheless, if the ' balance ' or ratio between the three main constituents-i.e., the proteins, fats, and carbohydrates-is not reasonably correct, in the long run the infant's nutrition will be bad." I am. Sir. vours faithfullv. nicious anaemia is the result of changes produced by the absorption of poisons from the alimentary canal due to a deficiency of the normal antiseptic action of the gastric juice. We do not feel that the existing evidence is sufficient for the acceptance of this view, and careful examination of Dr. Hurst's six paragraphs suffices to reveal the rather slender fabric with which the theory has been built. 1. We cannot agree with Dr. Hurst that " there is abundant evidence that the achlorhydria precedes the development of the anaemia." A long history of digestive disturbances " is not sufficient ground on which to diagnose achlorhydria, and against the one case in which achlorhydria was known to have preceded the anaemia by three years must be set 0ff such cases as that quoted by Sophie Hertzberg, in which there was a normal amount of HC1 in the stomach. 2. In every large series of cases of pernicious anaemia who have been subjected to gastric analysis there are to be found a few who apparently did have HCI in the stomach contents. We have not encountered such a case, but all that we have examined have been rather advanced cases. We did not in our paper suggest that the achlorhydria was the result of a change in the percentage of haemoglobin in the blood, but that it might be secondary to some blood change. It is probable that chemical changes occur in the blood in pernicious anaemia which have yet to be defined. 3. The persistence of achlorhydria during remissions is of little importance ; few cases of pernicious anaemia give even the clinical appearance of complete restoration to health between attacks, and no one can dogmatically assert that any case has definitely returned to normal. Dr. Hurst's own figures show that in the cases he quotes the haemoglobin percentage was not yet normal ; it may be that other chemical factors remain more seriously affected. 4'. There is certainly evidence of the occurrence of reduced gastric acidity after haemorrhage. We gave a clear example in our communication, and we learn that Mr. James Sherren described the same thing as long ago as 1911. Our personal experience is that even with bleeding gastric or duodenal ulcers a high acidity may persist ; we have not cared to perform gastric analysis soon after really severe hsemateifesis. 5. We tried in our paper to establish the protean nature of the secretory changes in cancer of the stomach ; that true achlorhydria is rare in this condition-rarer, indeed, than Dr. Hurst suggests-has been our experience. When it does occur we find that it is usually in the cachectic type of patient. The original observation of Samuel Fenwick was that gastric atrophy occurred in association with advanced cancer of the breast and other remote organs. 6. Dr. R. D. Passey, in common with other observers, found oxyntic cells present in the mucosa he examined ; this surely is more in favour of the achlorhydria being haematogenous in origin than of its being due to a gastric lesion. In setting out these arguments against those of Dr. Hurst our chief desire is not to belittle the theory to which he adheres, but rather to demonstrate that the existing evidence does not justify the adoption of any dogmatic view. If it be true, as Dr. Hurst believes, that gastrectomy predisposes a patient towards pernicious anemia, the fact is of tremendous import in view of the increasing frequency of this operation. Our chief wish in writing our communication was to direct attention to the evidence' of pancreatic deficiency in pernicious anaemia, and this evidence remains unaffected by the present controversy.—We are, Sir, yours faithfully,
doi:10.1016/s0140-6736(01)00882-0 fatcat:covixdebhfayfgdxixr2qt2ek4