GOITRE

Wairarapa Times-Age, 3 October 1938, Page 8

GOITRE

DEFICIENCY OF lODINE INCIDENCE AND CAUSATION ADDRESS BY DR C. E. HERCUS Consideration was given to the problem of goitre in both human beings and live stock at the final session of the New Zealand Grasslands Association Conference recently. The Otago branch of the Royal Society of New Zealand and visiting young farmers joined with the conferring body, and an address was given by Dr C. E. Hercus (dean of the Medical School), Otago University. Dr Hercus said that the appearance of the subject'of goitre on the programme of a Grasslands Conference drew attention to the close relationship between the sciences, basic and applied, and to the intimate dependence of man on his environment. “Goitre,” said Dr Hercus, “derived from, guttur, the throat, is the name given to chronic enlargements of the extremely important ductless gland which lies on either side of the upper part of the trachea in all vertebrate animals. This thyroid gland plays an essential role in growth and metabolism, controlling many physiological processes. In sharp contrast to the pituitary which, by means of a number of different hormones, presides over many bodily functions, the thyroid exerts its changes through but one hormone, an essential component of which is the element iodine. DISTRIBUTION OF DISEASE Goitre had been called the epidemic disease par excellence. Its striking regional variation was as clearly marked in certain islands of the Pacific as in other parts of the world. Japan was non-goitrous. The incidence was given as one per million. This country illustrated the close dependence of goitre incidence upon the utilisation of marine products, particularly seaweeds. Seaweed in some form appears in the daily dietary of most of the people of Japan. Two of his students, when in Japan in 1936 with the New Zealand University football team, found seaweed confections as popular with the Japanese as sweets were in this country. Seaweed was in regular use in soups and foods of various types. New Guinea, in contrast to Japan, had extensive areas in which goitre occurred. The natives living within reach of the sea utilised sea food cooked in sea water very extensively, and they were non-goitrous. “A large scale demonstration,” said Dr Hercus, “has been in progress in Dunedin in an institution of 170 young women for the last two years with results convincing, not only from the prophylactic, but also from the therapeutic standpoint. No goitres 'have developed among these young women during the period, and existing goitres have decreased in size. The effects are the more striking when contrasted with the results of a previous eight years’ experience in the same institution with the use of salt for all cooking and domestic purposes iodised according to Government regulations. During this period several goitres developed in spite of its regular daily use. This failure of the iodised salt to give complete protection has been noted in many other parts of New Zealand. Dr Baker-McLaglen, for example, in 1936, informed me that goitres were still developing in Hokitika in spite of the regular use of iodised salt. The failure is due to the inadequate ’ supply of iodine to the thyroid gland. In many private home in Dunedin and elsewhere, by means of various seaweed preparations, we have been successful in securing a daily supplementation of at least 100 micrograms, and the results have been altogether satisfactory. . “Since 1926, thanks to the willing co-operation of Dr McKillop, of the Sunnyside Mental Hospital, in Christchurch, w T e have been able to stage a large-scale 11-year demonstration of the effect of a supplementation of approximately 66 micrograms. _We have been able to secure this additional supplementation by means of standard iodised salt in virtue of the fact that in this institution we have been able to use iodised salt, not only for cooking and table purposes, but also for bread and butter making and in all malted foods. We have found that the average daily amount per head of salt taken for cooking and table purposes is six grams, whereas, if used in all salted food, the consumption rises to 11 grams. The results of this 66 micrograms addition have also been most convincing. . “The final line of evidence which compels us to the belief that lack of iodine is the fundamental cause of goitre in New Zealand is supplied by experimental work on various laboratory animals in which it can be shown that exposure to Jow iodine _ level dietaries leads to the production of goitre, which can be prevented by attention to this single, factor in the environment. All these converging lines of evidence, environmental, prophylactic, therapeutic, and experimental, embolden us to say that, though there are many accessory causes for thyroid enlargement, the essential cause in New Zealand is iodine deficiency.” lODISED SALT.

The prophylactic aspect of the goitre problem in New Zealand, he continued, resolved itself into securing for all the people all the time a daily supplementation of iodine of at least 100 micrograms. In the ideal method of prophylaxis this addition would be supplied automatically, and the best and most readily available method would be by the adoption, as the standard salt of this country, of salt adequately iodised. Failing this, measures must be taken to secure the daily use for all the people of some preparation of seaweed or of fishes rich in iodine. No possible ill-effects could accompany this physiological procedure. The present position in New Zealand was most unsatisfactory. Only approximately 30 per cent of the total domestic salt in use was iodised, in spite of 10 years of more or less continuous propaganda. The amount of iodised salt imported annually was only sufficient to supply each individual in the country with 1.4 grams of salt carrying never more than 6 micrograms of iodine, and frequently as low as 3. Even if used consistently for all table and cooking purposes, the present supplementation could not supply more than 36 micrograms daily, while it might be as low as 18 and yet comply with the regulations. While the problem of how to prevent goitre could be regarded as solved, the application of the knowledge awaited an informed public opinion. Many important problems still

confronted them in connection with the physiology and pathology of the gland, however, and it was their firm belief that medical research in this country should concentrate, in so far as resources permitted, on further exploration in this unknown country.