The A.B.-Z. of our own nutrition

by Horace Fletcher

It is in this way that I would explain the frequency of adenoids among the children of civilised communities. I claim, in fact, that this disease is largely dietetic in origin. I submit that a child whose nasal apparatus and naso-pharynx are well-grown and habitually bathed by a stream of pure blood and lymph, periodically accelerated by an ample and vigorous use of the masticatory muscles, is unlikely to contract adenoids. On the other hand, I contend that a child in whom these parts are ill-developed and bathed by an habitually sluggish stream of tainted blood and lymph—one, i. e., that is not only poisoned, but rarely, if ever, hurried along its lazy course by due exercise of the muscles of mastication—I submit that such a child runs great risk of contracting the disease. The influence in setting up adenoids of toxic saturation with its resulting catarrhal tendency is shown by the frequency with which this affection follows upon the rhinitis and naso-pharyngitis of measles and diphtheria, and in order to realise how greatly the circulation of blood and lymph in the walls of the naso-pharynx must be influenced by mastication, one has but to remember how very closely the pterygoids are related to this region; in exploring it for adenoids they can, indeed, often be felt to stand out prominently.[26]

This, then, is my explanation of the truly fearful prevalence of adenoids among the moderns. It is essentially a disease of pap-fed peoples. A child may, with the one exception that he is fed on a pappy, super-saccharide diet, be brought up under ideal health conditions. He may live in the heart of a dry, open country, far from the darkness, dust, and tainted atmosphere of the town, sleep with the windows open all night, live out of doors all day, be fed on the most nourishing (too nourishing, it may be) food, be clothed after the most approved methods, and yet, in spite of all this, we may find his naso-pharynx packed with adenoids. This disease is, in fact, scarcely less prevalent in the country than in the towns, scarcely less common among the rich than among the poor. Yet in primitive communities it is practically unknown. And what, I would ask, is the one condition in the material environment of my supposititious child differing from that of the primitive child? What but the factor of diet? Therefore, I say, the prevalence of adenoids among moderns must be the result of the modern system of feeding children, and the defective mastication which goes along with it.

That the foregoing is a grave indictment against that system, it need scarcely be said. For adenoid disease is fraught with many evils, among them mental hebetude, blocking of the Eustachian tubes, and manifold other auditory troubles, gastro-intestinal disturbances from the passage into the stomach of unhealthy discharges, and, most serious of all, nasal obstruction and consequent mouth-breathing. So serious are the evils connected with this latter habit that they demand more than a passing reference. Pronounced adenoid disease is always associated with mouth-breathing, and there can be no doubt that in the majority of these cases, the nasal obstruction is not in the nasal passages primarily, but is due to a blockage of the posterior nares by the adenoid growths, for it generally happens that nasal breathing is rapidly re-established after their removal, though in a certain proportion of cases the obstruction still persists, and has to be dealt with by treatment directed to the nasal passages themselves. Some have, indeed, contended that a primary nasal obstruction is one important factor in the induction of adenoids, leading as it does to a dry-cupping of the naso-pharynx during inspiration and to a consequent congestion of its lining membrane. I am quite ready to allow that this mechanism may play some part in causation, and such an assumption is in entire harmony with my main contention that adenoid disease is of dietetic origin, for nasal obstruction in children, other than that caused by adenoids, is mainly due to defective development of the nasal passages coupled with inflammation of their lining membrane, both of which conditions may, as we have seen, be essentially the outcome of defective diet.

Coming now to the evils resulting from mouth-breathing, we have first to remember that normally the air is inhaled through the nose, and is thus warmed, moistened, and filtered before being allowed to pass into the lungs; but in the mouth-breather the air, which may be dry, cold, and dust-laden, passes at once unprepared through the mouth into the lungs, impinging in its passage against the pharynx, thus drying and mechanically irritating the mouth, pharynx, larynx, and bronchial tubes, all of which are thereby predisposed to disease. In this way laryngitis and bronchitis, nay, even phthisis, may be induced. Dental caries is also predisposed to by the habit of breathing through the mouth. Mouth-breathing further interferes with the proper development of the cranial bones, but especially of the maxilla, giving rise to what may be termed the “mouth-breather’s jaw,” so characteristic is it I do not propose to discuss here the mechanism by which this deformity is produced, interesting though the question is; suffice it to say that nasal breathing is essential to the normal development of the jaws. The deformity in question, though it involves the maxilla chiefly, affects also the mandible from the fact of its being, to a large extent, moulded on the maxilla; in typical cases the maxilla is small and its alveolar ridge does not attain its normal length, but is compressed laterally towards the sagittal plane, giving rise to the false appearance of a “high arch” and often thrusting the anterior portion of the ridge forwards; the teeth, the growth of which is not so much interfered with as that of the imbedding bone, are thus prevented from taking up their proper positions and show irregularity, sometimes extreme. Dental irregularity may also, as we shall see, result from inadequate use of the jaws in mastication, but not to the extent which is frequently observed in the mouth-breather’s jaws, and therefore pronounced dental irregularity always shows that there has been protracted nasal obstruction, and this in the vast majority of cases implies the existence of adenoids, past or present; I say in the “vast majority,” for in a few rare cases long-continued nasal obstruction in children originates primarily in the nose and may lead to the typical mouth-breather’s jaw, with the resulting dental irregularity.

The tongue.—If the tongue is not properly exercised in childhood and youth, we find it imperfectly developed; hence in inefficient masticators it is generally small. It must not be forgotten in this connection that this organ is considerably exercised when the infant is at the breast, from which the milk is obtained, not by suction, but by a vigorous tugging and squeezing of the nipple (in which the tongue takes considerable part), whereby the gland is reflexly excited to secrete. When, on the other hand, the child feeds at the bottle he obtains his milk by actual suction, and generally through an orifice of such ample dimensions as to allow the bottle to be rapidly emptied with comparatively little exercise of the lips and tongue. In short, the breast-fed infant has to do some work for his living, and that of a sort calculated to promote the health of the jaws and their appendages, while the bottle-fed child can glut himself by doing very little more than opening his mouth; wherefore we find the tongue and adjacent parts less developed in the latter than in the former. It may be thought to be a matter of indifference whether the tongue develops to its normal proportions or remains small, but such is by no means the case, for, as Dr. J. Sim Wallace has shown, the pressure of this structure against the teeth promotes the normal development of the jaws, especially of the mandible, and when it is small they are apt to be so too.

The salivary glands.—Just as mastication increases the functional activity of the salivary glands and buccal glands and favours their normal development, so, contrariwise, inefficient mastication during early life fails to call forth their normal functional activity and to secure their adequate development. Thus we find that a child who has been brought up on hard, starchy foods, necessitating abundant mastication has much larger and more active salivary glands than one who has been fed on soft foods which slip down into the stomach before they have had the chance of being properly masticated, and it is needless to say that the more efficient these glands are the more likely is digestion to be carried out satisfactorily.

The jaw-bones.—If the jaws are not adequately exercised in youth by mastication they fail to grow to their normal size and shape, and there is apt in consequence to be overcrowding of the teeth. The main defect of the jaws in such cases is their smallness; they do not present that pronounced lateral compression and anterior protrusion which characterise the mouth-breather’s jaw, nor such extreme dental irregularity, the most common being overlapping of the incisors, displacement of the canines, and difficulties in regard to the eruption of the wisdom teeth from shortness of the alveolar ridge. I have already referred to the progressive shortening in the post-molar ridge, which has been taking place during man’s evolution from the anthropoid in correspondence with the alteration in his diet.

We thus see that defective use of the jaws leads to irregularity of the teeth (1) directly and (2) indirectly through the induction of adenoids. This irregularity is not only unsightly but leads to certain evils which thus primarily owe their origin, in large measure at least, to defective mastication. What, then, are these evils? In the first place, dental irregularity predisposes to dental caries by favouring the lodgement of food between the teeth; in the next place, it leads to defective “bite.” Now when the bite is defective adequate mastication is impossible, for not only is it impossible in these circumstances to oppose the teeth properly, but also, owing to their interlocking, to accomplish that free lateral movement of the lower teeth against the upper, which belongs to normal mastication. I do not say that defective bite is the sole cause of this imperfect lateral movement; it may, indeed, be observed in most moderns brought up on soft pappy food, whether the bite be good or not. Normal mastication is, in fact, becoming a lost art; the average modern masticates mainly by a vertical compression of the lower teeth against the upper, and in only a small degree by a lateral frictional movement which, it is needless to say, is the more effective method for grinding purposes; and it is, I doubt not, chiefly for this reason that the teeth of modern man are so much less worn down than those of primitive peoples.

The teeth.—Imperfect use of the teeth leads to many ills. When adequately exercised and made to execute for one or two hours every day a lively dance in their sockets, during which the circulation of blood and lymph in the tooth-pulp, periodontal membrane, and surrounding tissue of the gum is vigorously stimulated, and the cavity of the mouth is bathed in a copious flow of salivary and other buccal secretions, we have conditions which make alike for the health of the buccal mucous membrane, of the teeth, and of the periodontal membrane and alveoli; but when the circulation is not duly stimulated in this way the teeth do not develop properly, while the secretions of the mouth are apt to be scanty and unhealthy, both of which conditions predispose to caries. How far dental caries is due to inherent dental weakness and how far to faulty conditions outside the teeth we need not stop to inquire; Dr. Wallace attributes little influence to the former factor, contending that caries depends essentially upon faulty dental environment; and one can scarcely doubt that the state of the gums and of the oral secretions profoundly influences the growth of bacteria in the mouth, upon the acid yielded by which organisms the corrosion of the dental enamel essentially depends. Faulty conditions of the oral secretions likewise favour the deposit of tartar.

Another result of imperfect use of the teeth is undue thinness of the alveolar walls and periodontal membrane, in consequence of which the teeth are not so firmly held in their sockets as they should be. This is, I believe, one of the reasons why they are prone to fall out prematurely among the moderns: we know that the teeth tend to drop out in old people owing to a senile atrophy of the alveolar walls; the Haversian canals get smaller and may, indeed, disappear entirely, and it stands to reason that this atrophy must be hastened by inefficient exercise of the teeth. So far as I am able to gather from an examination of skulls in museums, the teeth are rarely shed among primitive peoples before extreme old age, while among moderns they frequently fall out long ere this is attained.