PHYSICAL AND MENTAL WELFARE

Wanganui Chronicle, Volume 83, Issue 243, 14 October 1939, Page 6

PHYSICAL AND MENTAL WELFARE

By Professor J. C. Drummond, . Department of Biochemistry University of London. Dear People. One sometimes wonders how much I greater must be the mass of evidence 1 proving the potential dangers of drink-' ing raw milk, before government. circles will recognise and openly ad- [ mit that public health must come [ before political considerations that' are trivial by comparison with the | savings of human lives. It is im- ' possible in the little space at present at my disposal to give anything approaching a comprehensive review of the weight of evidence we already possess. A few of the more outstanding facts can, however, be mentioned, j Dangers of fnpasteurised Milk. Tuberculosis affects something like ' 40 per cent of the cows in this country ' • Britain), and at least two per cent of ; them in such a manner that they are I yielding infected milk. Bovine tuber- j culosis is communicable to man is, in | fact, responsible for from 20 to 50 per I cent of the deaths attributable to tuberculosis In sites other than the j lungs. The number of deaths which ' can fairly be put to the account of [ milk infected with bovine turbercle | bacilli is about 2,500 a year at the j present time (Britain). The elabor- j ate precautions which are often taken I io provide the public with raw milk, i free from tubercle bacilli, have not • given the measure of safety that \yas optimistically expected. Examination of such milk shows that, although free | from T. 8., they are often infected with i the organisms responsible for undulant j fever and with strains of haemolytic | streptococcus, noth of which are liable! to cause serious illness and fatalities.. Little-known Epidemics. In one examination, the proportion! of samples of milk found to be infected with these two type of organ- ■■ ' ’ ■ ' ’ ■ ively. It is recognised to-day that , undulant fever is more common in ' man than - as suspected a tew years* ago, although the true incidence i-s j not yet known. The public usually > hears only about grave outbreaks of I milk-borne disease, such as the; disastrous m phoid epidemic at Bourne- [ mouth in 1936, and that of septic sore i throat at Hove in 1929. Few people! leaiise that there have been 140 epi- : demies in Great Britain, all attributable to infected milk. affecting over 15,000 persons, during the past 30 vears or so. A typical axampie is the outbreak of gastro-enteritis at Wilton, Salisbury, in October, 1936, when more than 100 children were infected by drinking raw milk which had become contaminated there being present in the herd just one cow which was a carrier of the organism concerned. Nutritive Qualities Undisturbed. This annual toll of sickness, invalidism and death could be reduced to ajmost negligible figures by efficient pasteurisation. With that statement not a single expert of any standing | would disagree. Such experts might j hesitate, however, to further the intro-j duction of measures to make pasteur- j isation compulsory if they feared that j such treatment would greatly reduce the nutritive value ot the milk. What are their views on this important matter to-day? Six years a go. Doctors Stirling and Blackwood reviewed in a very comprehensive manner the scientific evidence then available (“Nutritive Properties of Milk in Relation to Pasteurisation”, the Hannah Dairy Research Institute. 1933). They reached the conclusion that “There" do not appear to be any grounds for the belief that pasteurised milk is a less valuable component of the diet than r&w milk, for children ( who satisfy the bulk of their nutritive’ requirements from sources other thani milk.’* i

PASTEURISATION 2

.Values After Heating. i With regard to milk as food for j •younger children, the authorities in ! question expressed the opinion that there are “strong grounds for the belief that infants can satisfy ail their [requirements on diets of adequate lamounts of pasteurised milk, provided That extra vitamin D and, of course, [vitamin C, are added to the diet.” i Clearly, neither statement could be regarded as the last word. The reviewers admitted that the evidence available was far from adequate and ihat the question demanded furtherinvestigation. For vigorous steps in this direction we have to thank the Milk Nutrition Committee, established in 1934 under the auspices of a '.number of technical and scientific ‘bodies, and which met under the chairmanship of Lord Astor. The investigation which this committee projmoted have, in the short space of five [years, provided a large part of the convincing evidence which is now available to show how insignificant is the extent to which the nutritive value of milk is reduced by the various, forms of treatment in which heating •occurs. Daily Requirements. I Nor is the evidence of the Milk • Nutrition Committee, as well as that of the technical scientific bodies which [ worked in cooperation with that committee, the only evidence that has been obtained since 1933. On the contrary. independent investigations from I many other quarters have provided equally reassuring conclusions. Before pasing to a brief review of the scientific evidence that has recently been [obtained, it may be instructive to [survey the information regarding the [value of milk as a source of essential [mineral elements and vitamins, because, in considering the question of :the effect of heat on the nutritive lvalue of milk. it. is these constituents that occupy the chief place. Daily Requiiements. Calcium, [about lOOOnig.; phosphorus, about 1 1500 mg.; iron, 10 to 15mg.; vitamin !a, 2000 to 5000 units; vitamin B, 300 •to 500 units; vitamin C. 1000 to 1500 i units; vitamin D. 150 to 500 (child). [ Contents of One Pint Milk. Cal|ci uni, 680 mg.; phosphorus, 530 mg.; iron. 0.6 mg.; vitamin A. 400 to 4000 units: vitamin B, 150 units; vitamin C, 200 units; vitamin D, 0 to 50 units. Technical Changes. One of the most commonly encountered objections to the healing of milk is based on the fact that the solubility of certain of the lime-con-taining constituents may be changed. It is not surprising that this has given rise to the belief that some of the lime compounds of calcium (including calcium phosphate) can be assimilated by the mammalian digestive tract , without difficulty. In passing, it may be pointed out that the change which the natural calcium phosphate of milk [undergoes on heating is not one involving an actual change of solubility. .It is rather an alteration of the [physical condition.—a change which |is of no import whatever from the standpoint of nutrition. A series of experiments planned to compare the utilisation of the bone-forming elements of raw and pasteurised milk has shown that no significant differ- . ence can be detected. Yours as ever, i * ‘■ (Published by special permission of the [ . British Association). (To be continued)