[The complete text of the Lectures, with illustrations, may be obtained in pamphlet form, price 2s. 6d., on application to the Secretary, Royal Society of Arts, John Street, Adelphi, London, W.C.2.].
VARIETY OF DISEASE IN IMPROPERLY FED ANIMALS.
During the last eighteen years of my experimental work in India I used many thousands of animals — rats, pigeons, fowls, rabbits, guinea-pigs and monkeys– feeding them on diets not synthetically prepared from purified foodstuffs but from foodstuffs in common use by the people of India; my purpose, as previously hinted, being to learn what relation the food used by the people had to the diseases from which they suffered. At the risk of being tedious I shall now enumerate the maladies I have encountered in these improperly-fed animals, leaving out of count such manifestations of ill-health as weakness, lassitude, irritability and the like, which are commonly met with in malnourished animals.
Here is the list. Skin diseases: loss of hair, gangrene of the feet and tail, dermatitis, ulcers, abscesses, oedema. Diseases of the eye: conjunctivitis, corneal ulceration, xerophthalmia, panophthalmitis, cataract. Diseases of the ear: otitis media, pus in the middle ear. Diseases of the nose: rhinitis, sinusitis. Diseases of the lungs and respiratory passages: adenoids, pneumonia, broncho-pneumonia, bronchiectasis, pyothorax, pleurisy, haemothorax. Diseases of the alimentary tract: dental disease, dilatation of the stomach, gastric ulcer, epithelial new growths in the stomach (two cases of cancer), duodenal ulcer, duodenitis, enteritis, colitis, intussusception and a condition of the lower bowel suggestive of a precancerous state.
Diseases of the urinary tract: pyonephrosis, hydronephrosis, pyelitis, renal calculus, nephritis, urethral calculus, dilated ureters, vesical calculus, cystitis, incrusted cystitis. Diseases of the reproductive system: endometritis, ovaritis, death of the foetus in utero, premature birth, uterine haemorrhage, testicular disease. Diseases of the blood: anaemia, a pernicious type of anaemia, Bartonella muris anaemia. Diseases of the lymph and other glands; cysts, abscesses, enlarged glands.
Diseases of the endocrine glands: goitre, lymph-adenoid goitre, adrenal hypertrophy, atrophy of the thymus, haemorrhagic pancreatitis (very occasionally). Diseases of the heart: cardiac atrophy, cardiac hypertrophy, myocarditis, pericarditis, hydropericardium. Diseases of the nervous system: polyneuritis, beri-beri, degenerative lesions. Diseases of the bone: crooked spine, distorted vertebrae (no work was done on rickets — a known “deficiency disease”.) General diseases: malnutritional oedema, scurvy, prescorbutic states.
All these conditions of body, these states of ill-health, had a common causation; faulty nutrition, with or without infection. They are the clinical evidence — the signs and symptoms — of the structural and functional changes in organs or parts of the body that result directly or indirectly from faulty nutrition. It will be noted that local infections and maladies of a chronic and degenerative kind are conspicuous amongst them.
These maladies are, in short, the symptoms of malnutrition as observed in animals fed on faulty diets — some of them admittedly very faulty– in use by human beings, or on food materials in use by them. It is reasonable, then, to expect that maladies of a similar order are likely to result from malnutrition in human beings. In my next lecture I shall endeavour to make clear how it is that food of improper constitution leads to that disturbance of structure or function of organs or parts of the body which is “disease”.
RELATION OF CERTAIN FOOD ESSENTIALS TO STRUCTURE AND FUNCTIONS OF THE BODY.
The mineral constituents of food consist of some twenty elements of which eleven– previously enumerated (Lecture I)– are definitely known to be essential to vital processes. They are all intimately related one to another by complex chemical combinations and interactions, so that it is difficult to separate the functions of one from those of another. In general these functions are to provide building-materials for the fabric, and to regulate various functions, of the body.
NATIONAL HEALTH AND NUTRITION.
If we look upon ” infection” of whatever kind, be it due to microbe, protozoa, metazoa, or invisible virus, or to the intervention of vectors of pathogenic agents, as the evidence of personal or environmental uncleanliness, then it may be said that the two chief causes of diseases are faulty food and dirt. These two are the senior partners in the criminal business of disease- production– each the coadjutor of the other.
It is along lines of improved cleanliness, both personal and environmental, that the triumphs of modern medicine have lain; it is along lines of improved nutrition that greater triumphs still remain to be achieved. Some years ago I made the statement that “the newer knowledge of nutrition is the greatest advance in medical science since the days of Lister.
When physicians, medical officers of health and the lay public learn to apply the principles which this newer knowledge has to impart . . . then will it do for medicine what asepsis has done for surgery.” I see no reason, in these later days, to detract from this view; on the contrary, there is every reason to emphasize it the more, particularly in regard to preventive medicine.
In this country the conviction that faulty food, and the faulty nutrition resulting from it, is a principal cause of ill-health, does not appear to be acquired so readily as it is in the Tropics. Perhaps it is that as an island race we have no others, at close range, with whom to compare ourselves.
The tribes of the Indian Frontier are far removed from the slums of our great cities; and it would be as difficult for the slum-dweller to realize the perfection of physique to which these tribes attain, though nourished on the simplest and least varied kinds of foods, as it would be for the Frontier tribesmen to understand that the physical imperfections of so many of the dwellers in the slums are largely due to the imperfections of the foods on which they are reared. Nevertheless, things nutritional are not, in essence, so different in India and in England as they may seem.
It is not only amongst the poorer classes in this country, but also amongst those who are better off, that the diet is commonly excessively rich in vitamin-poor, mineral-poor starchy foods and in protein-less, vitamin-less, minerally deficient sugar.
It is impossible for people subsisting on such diets to remain in good health. “It is only being gradually realized,” says Dr. Friend, whose recently published book, The Schoolboy, is so valuable a contribution to the problems of food and nutrition, “that the deficiency of white bread in vitamin B is one of the most serious dietary deficiencies to which our populations are being subjected at the present time”. To this I would add that incoordinate use of refined sugar is one of the most serious addictions of the day.
That the insufficient ingestion of vitamin B1 i an important and widespread cause of ill-health–especially of gastro-intestinal ill-health– is now recognized in America, where “the bread-meat- potato-sugar” diet of many American people has recently been shown to be dangerously low in this important factor, unless it is supplemented with a sufficiency of milk, eggs, fruits, nuts and vegetables (Sure, 1933).
And if in America, why not this country also, where the average diet is of the same “bread-meat- potato-sugar” sort ? You will remember that 10 per cent. of the rats fed on a diet such as is commonly used by the poorer classes in this country developed polyneuritis — a sure sign that it was deficient in this factor. According to American observers the mal-effects of such a diet are chiefly to be observed in children who exhibit poor appetites, poor growth, nervousness, constipation and other digestive disorders: effects which I observed, and recorded, in monkeys eighteen years ago.
What evidence is there of physical inefficiency in this country? and what that such as may exist is related in its origin to faulty nutrition? For answer to the first of these questions I must turn to certain authoritative publications. From the first of these — the Report of the Adjuvant-General for the year 1934 — I quote the following passage: “What was disconcerting to any citizen with a care for the good of his country was that over 52 per cent. of the men who went to the recruiting office did not come up to the physical standard laid down. In the big industrial areas of the North the percentage of rejections rose to sixty- eight.”
The opinion of a high military medical authority was that the chief cause of the mens rejection was malnutrition during childhood. These figures are in themselves sufficiently disconcerting, but more so perhaps when it seems likely that the men who did present themselves for recruitment were not so physically impaired as many who did not. And if so high a percentage of men failed to come up to the by no means exacting physical standard laid down by the Army authorities, how many of their womenkind were likely to be physically inefficient?.
Another example, also of recent date, is still more disturbing: Not long ago the Pioneer Health Centre in Peckham carried out a survey of families of the artisan class, for whom the centre is intended. This survey revealed that 90 per cent. of those over 25 years of age had some physical defect.
From another source I glean the following statement: “Among the insured population there were lost in 1933 a total of 29,000,000 weeks of work. To this staggering loss must be added the cost of replacement of labour and the expense entailed in the care of the sick during the period of incapacity. These figures represent a heavy burden upon the community which is largely unnecessary.”
It is a burden, however, that the community must continue to bear until it has learned that to be physically efficient the individuals comprising it must not only be taught to practice the principles of nutrition, but be provided with the means to practice them. It is to be noted in connection with this enormous amount of certified sickness that it was not of the killing kind — “the people were sick but not mortally sick”. [ Spectator, October 19th, 1934, p.586.].
There is, too, the very high incidence of anaemia, due to deficiency of iron, in working-class women, to which attention has recently been drawn by Professor Davidson, of Aberdeen, “If,” he says, “the percentage of anaemic women found in Aberdeen is present in the industrial areas of the South (and we believe that anaemia may be even more serious there, since economic conditions are worse and the cost of living higher), then the loss of economic efficiency of the working-class mothers in this country must be enormous.”.
The still very high incidence of tuberculosis, especially in adolescence, is another outstanding evidence of national ill- health: “During the last completed decade, 1921-30, there were, roughly speaking, forty-five thousand deaths of males and an equal number of females at ages 15-30. Amongst the males very nearly one-third of this mortality was due to tuberculosis while amongst the females the proportion was as high as one-half.” [+ Report of the Chief Medical Officer of Health, 1933.]
It seems probable that a principal, if not a paramount, cause of this high incidence of, and mortality from, tuberculosis at this particular period of life is faulty food deficient in vitamin A, involving a low content of this vitamin in lung tissue and consequent susceptibility of the lung to infection.
As a final example of the prevalence of physical inefficiency, malnutrition in childhood may be cited. “In his Annual Report for the year 1934, the Chief Medical Officer of the Board of Education repeats the emphasis of former reports on the necessity for satisfactory nutrition. During the routine medical examination 12 children per 1,000 were found to be malnourished and 14 per 1,000 under-nourished” (I quote from the British Medical Journal).
It may be taken as certain that a major proportion of this faulty nutrition was due to food of improper quality or to insufficient food or to both. Believing, as I do, that sickness is more often the result of malnutrition than malnutrition the result of sickness. I venture to think that the evidences of malnutrition in school children are likely to be more widespread than these figures indicate.
For it is not only that children suffering from malnutrition are under-weight or undergrown; that there is a disproportion between their weight and height; that their posture is poor; that they are often round-shouldered and have protruding bellies, winged scapulae and lordosis; that they are of poor muscular development and easily fatigued; that they are irritable, haggard, anxious and, perhaps, mentally slow if not precocious; that they are wakeful, restless, and often troubled with unpleasant dreams; that they have headache and fleeting pains, sometimes in one part of the body, sometimes in another; although all these are signs of malnutrition. But there are others, indicating disturbances in structure or in function of organs or parts of the body: the circulation is poor; the skin in mottled or dry and hot, or moist, cold and clammy; there is usually anaemia; the digestive system is quite commonly unstable or disordered, constipation is frequent or may alternate with diarrhoea, the appetite is capricious — the desire for “sweats” is often inordinate — dental caries is the rule — and susceptibility to infection is very marked, especially infection of the upper respiratory passages.
It is well enough to say that malnutrition may be brought about by faulty health habits or by physical defects, such as dental decay or gastro- intestinal disorder; it may. But these physical defects, this bad or capricious appetite, this constipation or digestive disturbance, this anaemia, this poor circulation,. this faulty function of the skin — these are themselves consequences of faulty nutrition and, as a rule, it is this that gives rise to them, not they that give rise to the faulty nutrition.
If we take this view of “malnutrition” in school children — and for my own part I believe it to be the correct one– then it will be found that there are in this country not 12 per 1,000 who are suffering from it, but several times that number; nor will it be found to be confined exclusively to the poorer classes. Indeed, the widespread incidence of dental caries and of minor rickets is, in itself, sufficient evidence that this is so.
There is one certain means of detecting dietetic malnutrition and that is by the assessment of the nutritive value of the diet that is actually being consumed; and in making this assessment attention must be paid as much to such essentials as calcium, phosphorus, iron and iodine as to vitamins, proteins and energy-bearing foods. If the diet does not contain in adequate amounts all elements and complexes needed for normal nutrition, then the user of it is suffering from, or will suffer from, malnutrition.
It seems probable that a cause of malnutrition which may be overlooked is the non- provision of sufficient energy-bearing foods to meet the enormous expenditure of energy by growing children consequent on their bodily activities in sports and games.
I was assured recently by one who labours in the East End of London that such “fresh” vegetable foods as ultimately penetrate into that locality are usually many days old; and I am reminded, in this connection, of certain interesting observations made some time ago by one of my Indian assistants. He found that within seventy-two hours of gathering green vegetables from my well- tended kitchen garden in Coonoor, they lost the major part of their vitamin C content.
I do not know whether the rapidity of this loss would be as great in England, where climatic conditions are so different; but it seems safe to assume that by the time their sparse supply of leafy vegetables reaches the dwellers in the East End of London the vitamin C content is considerably reduced.
PREVENTION OF DISEASE BY DIET.
Concerning the matter of disease prevention and of the part which properly-constituted food may play therein, I need give only three examples: the first provided by Miss Margaret McMillan, in her book: The Nursery School– which should be an obligatory text-book for every student of medicine; the second by the Papworth Village Settlement for sufferers from tuberculosis; and the third by the anti-natal work now being done in Dublin. Many others could, of course, be given.
Hear what Miss McMillan had to say of the weakly and ill-conditioned children who came from the slums of Deptford to her nursery school; children, rickety and bronchitic; children with adenoids and dental caries; children with inflammatory states of eyes, nose, ear and throat. After they have been nutured and properly fed for three or four years they are, she tells us, almost all cured of any ailments they may have had: “they are all straight and well grown, the average child is a well-made child, with clean skin, alert, sociable, eager for life and new experiences.” He does not need, she says, to see the doctor or the dentist, and he has none of the minor ailments that affect the children of the slums.
Surely this is an achievement of the highest order, an answer to the question how best to deal with “the minor ailments that affect the children of the slums”, and a cogent reason for the establishment throughout the length and breadth of the land of nursery schools of the McMillan type. It is a heartening sign of the times that the present Government intends actively to encourage their establishment.
And at the Papworth Village Settlement for the subjects of tuberculosis, what do we find? That in this village of 400 persons no child born there during the twenty years of its existence has, while a member of the community, contracted tuberculosis of the lungs, bones, joints, cerebral membranes, nor indeed any clinical form of the disease. Yet these children are the offspring of parents who suffer from tuberculosis and are in constant contact with them.
In this matter of education in the principles of nutrition two of the great professions — the medical and the scholastic — are in a position greatly to aid the endeavours of Government in “the building of an AI nation”. In regard to my own profession I may repeat what I wrote fifteen years ago: ” It is for us so to instruct ourselves that we may . . . use our newer knowledge to the end that customs and prejudices may be broken and a more adequate dietary secured for those under our care.”
“There can be no doubt, said the British Medical Journal, in a leading article last year, “but that this newer knowledge of nutrition has placed in the hands of our profession a potent weapon against disease –a potent instrument in the promotion of physical efficiency and well-being. It behoves us, therefore, to become proficient in this knowledge, to apply it in the daily course of our work, and to spread it by every means in our power. A special responsibility attaches to our medical schools in this respect.”
“At present medical students during the early years of their course are given a few lectures and demonstrations dealing with the physiology of nutrition, and perhaps carry out a little laboratory work in this field; the subject is presented as a chapter of physiology, and not as an integral part of preventive medicine”.
The next most important direction in which educational effort is required is in the teaching of the elements of nutrition to school children:”We spend million,” said Lord Bledisloe in a letter to The Times, [ November 6th, 1935.] “on feeding the minds of the youth of the nation. Is it not time that we spent a little (as an essential part of all school curricula) on showing those young people how rationally and sensibly to feed their bodies and those of their prospective progeny?”
Here he goes to the root of the matter, for it is only by the instruction of youth that the faulty food habits of the people can ultimately be altered and the desire created for those things that be good from the nutritional point of view. This desire will lead to the demand for them, may be translated into the greater production of them and, perhaps, lead also to the return of many more people to the land — a thing greatly to be desired.
But to teach the children the teachers must themselves be taught, and this requires the adequate provision in all training colleges for prospective entrants into the scholastic profession of facilities for the acquisition of a thorough knowledge of the subject. These facilities do not, so far as I can learn, now exist, is an urgent matter. It “should set the Board of Education thinking more deeply on a question which vitally affects our national physique”.