16 JULY 1932, Page 16

TEETH AND DIET [To the Editor of the SPECTATOR.] S1R,—I

wish to thank Mr. Dugald Semple for his generous and inquiring remarks. To these latter I shall reply seriatim.

Germs.—Dentally speaking, these are not now held in such esteem as heretofore. Germs are always present in the mouth, but it is a debatable point whether one is justified in assuming that, because they are found in decay and pyorrhoea, it is cause and effect. Dr. P. R. Howe, an investigator of international repute, writing regarding his dietetic experiments, says : " So long as the diet is normal, it has been found impossible to cause dental decay or pyorrhoea by maintaining fermentation in the mouth, or by feeding or injecting those bacteria believed to be most actively associated with dental disease."

Persistent dental disease.—Mr. Semple instances persons with defective teeth in spite of adherence to such a diet as was outlined in my article. But there are satisfactory explanations, not the least important of which is that a proper foundation for sound bones and teeth was not laid during the ante-natal and childhood periods. Even with these severe handicaps, a rational diet will reduce the incidence and severity of dental disease.

Sugar.—Undoubtedly, honey, raisins, dates and other sweet fruits are rich in sugar ; whether cane or other variety, it is in a natural unrefined state and combined with organic mineral salts ; thus the body is able to assimilate the sugar without harming the teeth. The refined variety is highly concentrated, denaturalized and largely deprived of its mineral content.

Experimentation (human and animal).—The proper study of mankind is man, and the most that can reasonably be expected from animal dietetic experiments are clues, later, to be confirmed on human beings ; anthropoids have yielded the best results, because their dental apparatus is very closely akin to man's. Mr. Semple refers to experimental animals, living under " unnatural conditions," yet I hardly imagine he thereby wants to infer that the average Britisher is, to-day, living under natural conditions ! He also suggests that dietetic experiments on animals are cruel, but I make bold to state that practically every child (in embryo or born) in every civilized country, to-day, is the unconscious victim of hap- hazard dietetics, resulting in more suffering and ill-health than is the case with experimental animals. Yet we do not label this as cruelty, although, in my opinion, it is infinitely more so than the feeding of animals with certain diets.

Mr. Semple suggests that children, attending schools and

health clinics, might be made available for studying the causation of dental disease, but, even now, those in authority find difficulty in securing parents' consent to urgent dental treatment being undertaken for their children. Would they not, therefore, object were drastic dietetic changes suggested •t Even were this consent secured, the result would -prove incomplete and misleading; absolute control could not be exercised over lengthened periods—perhaps several year,

would be required. •

I trust that the above explanations will help to clarify the points under discussion.—I am, Sir, &c., J. MENZIES CAMPBELL.

C/o Messrs. Heinemann, 99 Great Russell Street, W.C.1'.