STORY OF THE BONES

Evening Star, Issue 21583, 1 December 1933, Page 13

STORY OF THE BONES

THEIR DEVELOPMENT AND MAINTENANCE TEEMING WITH LIFE AND ACTIVITY Dr C. K. Burns, in an address given yesterday afternoon to the annual meeting of the Dunedin branch of the Plnnket Society on the subject of ‘ The Story of the Bones,’ deeply interested his hearers. He pointed out that there were three aspects of the life and work of this community to which lie wished to draw attention, illustrating as they did important lessons in the nutrition and development of the growing child. There was first of all the matter of the development and maintenance of the bones in a state of healthy repair and efficiency. Then there was the function of the bones as a storehouse (for certain substances necessary to the life and well-being of other tissues and organs), and finally there was their function as a manufacturing shop for the various elements which went to make up the cellular content of the blood stream. FORMATION OF BONES. Bones were formed in different ways, but the commonest type consisted of lamellae or layers of hard calcium phosphate, laid down on a matrix or scaffolding of dense fibrous tissue. Other substances went to make up this concrete, but it was largely calcium phosphate. Now they were_ apt to think that, once formed, their bones remained unaltered and unalterable throughout life, given their escape from disease and accident; that like a stone or concrete building they remained fixed and impregnable; but it was not so, Nature was not satisfied with the permanence of concrete structures; and it was an interesting commentary on her foresight that she did not wait for trouble, but kept up a continual process of replacement and repair. All day long and all through the night there were little cells at work eating away tiny fragments of bone; but, fast as they pulled down one fragment, other cell's hurried up to replace it. They had seen their tramway repair gangs at work; there seemed no end to their chipping and undermining of the roadway along the tram tracks; but they did it in little sections so that the trains went their way without let or hindrance; and as fast as one new section was chipped out the last was refilled. Just as their tram tracks were forever being removed and replaced, so, too* were their bones. They did not know that the little workmen, the bone cells

which remove their old bone and replaced it, had time off for food and sleep, or for smokes or for gossip. He was inclined to think that they worked till they were too tired to go on any longer efficiently, and that they were then quietly but expeditiously removed to the lethal chamber and replaced by new and efficient colleagues. VALUE OF DIET. And so it was important, not only for the child, but for the adult as well, that the diet should contain a sufficiency of these important elements — namely, calcium and phosphorus—which made up the solid substance of their bones; and it was right and profitable just to remind themselves whence came these elements. Calcium was derived principally from milk, butter, cheese, eggs, green vegetables, and nuts; while phosphorus was supplied by meat, milk, egg yolk (and as inorganic phosphate). More work had been done in relation to the calcium requirements of the body than as regarded the phosphorus requirements. It was estimated that up to one gram—that was fifteen grains, or a quarter of a teaspoonful—of calcium as such should enter the body daily to meet all demands—not much really when one considered the extent of the skeleton—and it was to be remembered alongside this figure that one pint of milk contained _ about threequarters of a gram of this element. QUESTION OF ABSORPTION. When they were considering the calcium content of the diet they had to consider also the matter.of absorption; and calcium was a substance notoriously difficult of absorption. When there was a large supply of it and a correspondingly large supply of phosphorus in the "diet, despite this difficulty, enough of it would pass into the blood stream to meet all wants. But to add to this difficulty it had been found that there were certain foods which contained a substance called “ toxamin ” which acted as a positive hindering agent in the absorption of calcium. The foods which contained this substance were the cereals—wheat, oats, maize, etc.— and so bread, oatmeal, and such everyday foods were definitely harmful in this way, and required to be counteracted by others which contained some neutralising agents to this toxamin. Nature, ever 'mindful of their necessities and their potential difficulties, had provided them with such a substance—vitamin D—a substance _ which, given good exposure of their skins to the sunlight, could be prepared in their own bodies; or, failing that, could be obtained from such foods as the fat of meat and fish, milk, cheese, butter, and egg yolk. TEEMING WITH LIFE.

Their bones ■were not the dry uninteresting structures they were inclined to think they were—mere props or supports—giving stability and form to the limbs and trunk and face, and protection to the organs of the chest and to the brain. No, they were organs teeming with life and activity, and responding to conditions of health and disease as did all other organs._ He would mention but one condition m 'which the bones suffered in common

with other organs and tissues, and that was rickets. We have seen that in order to obtain satisfactory bone formation there was required a sufficiency of two elements—calcium and phosphorus. If the balance was upset n either direction, faulty bone formation which, speaking very broadly, constituted rickets—was the result. PERFECT TEETH. If they could believe Edward Mellanby, and to his researches into the bone work the people of the East were for ever in debt, perfect teeth could be ensured in the young by feeding them in the same sort of way as one to prevent rickets, and that was by giving liberally of milk, eggs, cheese, vegetables, and fruit, with cod-liver oil op its equivalent of extracted vitamin D regularly, and at the same time keeping low "in amount all cereals. MORAL OF THE STORY. And what was the moral of this story of the bones ? It was this: That since the bones of the growing child and the bones of the grown-up person were alike in structure, in everyday needs, and in activities, so, too, must they be the same in their requirements. Ifc wa strue enough that the bones of the infant and of the child and of the adolescent required more, relatively, of this and of that than did those of the adult person; but it was a matter of degree—of amount—the actual substances required were the same. This country of theirs was filled to overflowing with all those foods which were so much needed to make healthy bones and healthy tissues generally. There was no reason whatever against their showing the world what could be clone in the development of a physically healthy race from the nutritional point of view. It could be done. Their own society, under the guidance of its farseeing and ever-vigilant founder, had commenced the work ; and its success was such that everyone who ran might read. Why should not this work be earned on • why should it not be the case that he who has been properly fed as the child of to-day should ba properly fed as the man of to-morrow ■* It was not sufficient to supply people with sufficient food to satisfy the pangs of hunger. They must remember those little workmen who in silence and without grumbling all day and all through the night worked without ceasing till they died; they must assure themselves that from birth till death of the body as a whole they were supplied nob with foods which might be poisons, bub with foods which were only foods. Dr E. H. Williams proposed a vote of thanks to Dr Burns for his interesting and instructive address. He said that Dr Burns had made his address so extremely fascinating that_ he was sure everyone present appreciated it greatly. The society was fortunate in that year after year those present ab the annual meetings had the privilege of listening to members of tbe profession or of the professorial staff on subjects applicable to the work of the kocietv. T’he address that day was in keeping with those heard at previous annual meetings.

The motion was carried by acclama. tion.