Nutritional problems in the Arctic On page 624 of this issue of the Jour¬ nal Clow, Laberge and Scriver report the results of a study of the prevalence of neonatal hypertyrosinemia in an Inuit population. The rate was almost 30 times higher than would be ex¬ pected for the general Canadian popu¬ lation. The authors point out that the long-term effect of hypertyrosinemia on health remains uncertain, but that the possibility of developmental se¬ quelae is such that a prevalence of this
cannot be ignored. Clow and colleagues suggest that the most plausible explanation is that neonatal hypertyrosinemia is second¬ ary to deficiency of ascorbic acid. The tissues of the mothers of these infants may be depleted of this vitamin, which jeopardizes the condition of the infant at birth. They further suggest that when these infants are fed cow's-milk formulas, ascorbic acid intake will be low unless vitamin C supplements are given; the intake of tyrosine (and probably also phenylalanine) will be sufficiently high that the metabolic capacity for tyrosine breakdown is ex¬ ceeded and tyrosinemia results. The primary defect is, then, in ascorbic acid supply; the precipitating factor is the high content of aromatic amino acids in the milk formulas; both factors re¬ sult from the nutritional practices of the population under study. The postulate that the tissues of both mothers and infants may have been depleted of ascorbic acid is sup¬ ported by the results of the national survey conducted by Nutrition Can¬ ada. Among the Inuit serum ascorbate concentrations were extremely low and
magnitude
gingival changes (bleeding gums) were highly prevalent. Together these ob¬ servations strongly suggest that ascor¬ bic acid deficiency is chronic in this Northern population, even though clas¬ sic scurvy does not seem to be a major problem. Clow and colleagues are probably
correct. On the basis of their postulate the authors have pointed to hitherto
unnoticed clinical sequelae of a nu¬ tritional inadequacy. The relation of ascorbic acid deficiency and hyper¬ tyrosinemia has been described before, but the prevalence data presented by these authors are what is startling. Ascorbic acid depletion was not the only nutritional problem among the Inuit noted in the Nutrition Canada survey. Compared with the general Canadian population the Inuit had much lower serum concentrations of folic acid. The suggestion of a dual problem of depletion of ascorbic acid and folic acid in this population is not surprising: their lack of ready ac¬ cess to fresh fruits and vegetables makes low intake of both nutrients likely. In contrast, their intake of thi¬ amine, riboflavin, niacin and protein appeared to be relatively high. Intake of vitamin A was reported to be low and serum concentrations were gen¬ erally lower than in the total Canadian population. Although overt signs of clinical deficiency were not seen, the dietary and serum evidence suggests that depletion of liver storage of this vitamin may be common among the Inuit. Anemia was not prevalent among either the Inuit or the general population, but the Nutrition Canada study presented ample evidence that iron depletion is relatively prevalent among segments of the general popula¬ tion and even more prevalent among the Inuit. The paper by Clow and colleagues adds another possible dimension to these nutritional observations. All too often there is a tendency to dismiss as relatively unimportant the observa¬ tion of nutrient depletion when there are no signs of the classic deficiency diseases. Concern about "subclinical malnutrition" has not often been given a high priority in health planning. At least in the case of ascorbic acid, Clow
colleagues postulate that there are secondary clinical sequelae of a nu¬ trient deficiency that are not sought in a conventional nutrition survey. One must ask whether among this popula¬ tion, and others, there are undetected sequelae of the apparent depletion of folic acid, vitamin A and iron. The authors are careful to point out that while their postulate seems to be the most reasonable explanation of their observations, the available data do not prove the postulate. Because of the potential long-term sequelae of hypertyrosinemia it is important to establish its cause in this population. If indeed it is secondary to a nutri¬ tional inadequacy, the need to correct this and other nutritional problems among the Inuit becomes even more urgent. We are prepared to spend large amounts of money in screening and treatment programs for phenylketonu¬
and
ria because of the known effects of this inborn error of metabolism. The frequency of phenylketonuria is about 1 in 10 000. The frequency of tyro¬ sinemia in the first study of Clow and colleagues was about 1500 in 10 000. Even if the probability of major se¬ quelae is these infants is low, can we afford to ignore the risks? Of great concern, then, is the au¬ thors* statement that it is difficult to acquire follow-up data that might sup¬ port or refute their postulate. When the same population was studied a year later the prevalence of hypertyrosine¬ mia was about half that initially noted. Information about changes that had occurred in this population and its health services during that year would clarify the situation. Paired maternalinfant blood samples collected at the time of birth could be analysed to test the postulated relation between ascor¬ bic acid values in mother and infant. A double-blind supplementation trial would test the entire postulate and might provide specific evidence of the
CMA JOURNAL/OCTOBER 4, 1975/VOL. 113 601
investigated to the point that there is understandable reluctance on their part and on the government's part to agree to yet another investigation. Nevertheless, the questions now to be posed are so important, so simple to answer, and so practical in terms of immediate benefit to the Inuit that there should be no objection to seek-
ing the answers. There is a clear responsibility to determine the cause of this problem and to help the Inuit find an acceptable and effective solution.
Many of the visitors to CMA House sembled from the miscellany of cartons in Ottawa have availed themselves of in which it had been kept hitherto, and the invitation in the lobby to inspect its organization and cataloguing are some of the association's archives dis- proceeding well. This task has served played in the area adjoining the li- to heighten the realization of how many brary. Here can be found many of the and how serious are the gaps in our treasures presented by various organi- collection. Chiefly to be regretted is zations on ceremonial occasions - the lack of a representative library of silver and glass, scrolls, photographs works on medical history and partiof eminent past presidents, the first cularly Canadian medical history. minute books of executive meetings, In this country a number of valuable important numbers of the Canadian collections of such books exist, most Medical Association Journal and other of them attached to the libraries of the memorabilia. However, the archival various medical schools. Examples are material in our possession is by no the famous Osler Library at McGill means limited to this group of items. and the Ross Mitchell Room at the Admittedly the selection on view, University of Manitoba. An outstandchosen and arranged with perceptive ing store of rare medical books belongs care by that devotee of medical his- to the Academy of Medicine at Totory, Dr. A.D. Kelly, represents. the ronto, which also possesses a superb choicest pieces, but there is also much collection of medical artefacts. There that has been stored during the years are also at the present time many local in makeshift receptacles 'and relegated medical societies active in the gathering to less accessible areas of the building. of archives relating to their particular Its accumulation has been pursued district or province. It would be unrealistic for the CMA more assiduously in some periods than in others, depending on the degree of to have as its objective the duplication interest of the individuals responsible. or emulation of such collections as It has to be confessed that there are these. However, in the headquarters of serious gaps and deficiencies. Most of the organization it is desirable to have the material is documentary in nature at least a library that contains those volumes that are basic to the history and we possess few artefacts. It is encouraging to be able to report of medicine in Canada. A small but that there are prospects of amendment regular flow of enquiries and requests of this somewhat unsatisfactory situa- is directed to the association for intion. Last year the past presidents of formation on medical historical matthe CMA formed a subcommittee with ters and at present questioners must Dr. Harry Roberts as chairman to ad- be referred to other sources of help. vance the interest in Canadian archives Our aim should be to provide a reand history. This group has been ex- source and reference centre in medical tremely active since its first meeting archives and history. To build up the type of library that in December 1974. A curator has been appointed on a part-time basis, the ma- is contemplated is by no means a terial in our possession has been as- simple enterprise. It is not, of course,
just a matter of purchasing what is needful. Most of the essential items are out of print and available only as they come on the market through the disposal of private collections. One other source of supply we are desirous of utilizing is our own members. We would earnestly request any of these who possess works on the history of medicine or dealing with the local or provincial medical scene to give thought to donating them to the library at CMA House. It is highly possible that some extremely important works stand on the shelves of doctors who have had their enjoyment from reading and owning them but who will be willing to part with them to their own professional organization. Old and curious medical instruments and other artefacts will be equally welcome. Donors may be assured that their gifts will be respectfully treated and their receipt will be acknowledged in the columns of the Journal. Such activity in this field as is envisaged corresponds with the upsurge in interest in the history of Canadian medicine evidenced by the large attendances at meetings of the section at the CMA annual meetings of last year and this year. The story of the contribution of *the medical profession in the early days of our country is a fascinating and inspiring one and it is right that we should become familiar with it. The CMA intends to do all in its power to promote interest in this absorbing subject and, as far as it is able, to provide the means to satisfy it.
efficacy of short-term intervention and define goals for an approach to improvement of nutritional practices over a longer period. The data required would not be extensive and the study costs would not be high. Why, then, the apparent reluctance to probe a potentially serious health problem? The Inuit have been examined and
G.H. BEATON, PH D
Professor and chairman, Department of nutrition and food science, Faculty of medicine, University of Toronto Toronto, Ont.
CMA Archives
602 CMA JOURNAL/OCTOBER 4, 1975/VOL. 113
A.W. ANDISON, MD, FRCOG, FRCS[C]
CMA House 1867 Alta Vista Dr. Ottawa, Out.
cannot be ignored. Clow and colleagues suggest that the most plausible explanation is that neonatal hypertyrosinemia is second¬ ary to deficiency of ascorbic acid. The tissues of the mothers of these infants may be depleted of this vitamin, which jeopardizes the condition of the infant at birth. They further suggest that when these infants are fed cow's-milk formulas, ascorbic acid intake will be low unless vitamin C supplements are given; the intake of tyrosine (and probably also phenylalanine) will be sufficiently high that the metabolic capacity for tyrosine breakdown is ex¬ ceeded and tyrosinemia results. The primary defect is, then, in ascorbic acid supply; the precipitating factor is the high content of aromatic amino acids in the milk formulas; both factors re¬ sult from the nutritional practices of the population under study. The postulate that the tissues of both mothers and infants may have been depleted of ascorbic acid is sup¬ ported by the results of the national survey conducted by Nutrition Can¬ ada. Among the Inuit serum ascorbate concentrations were extremely low and
magnitude
gingival changes (bleeding gums) were highly prevalent. Together these ob¬ servations strongly suggest that ascor¬ bic acid deficiency is chronic in this Northern population, even though clas¬ sic scurvy does not seem to be a major problem. Clow and colleagues are probably
correct. On the basis of their postulate the authors have pointed to hitherto
unnoticed clinical sequelae of a nu¬ tritional inadequacy. The relation of ascorbic acid deficiency and hyper¬ tyrosinemia has been described before, but the prevalence data presented by these authors are what is startling. Ascorbic acid depletion was not the only nutritional problem among the Inuit noted in the Nutrition Canada survey. Compared with the general Canadian population the Inuit had much lower serum concentrations of folic acid. The suggestion of a dual problem of depletion of ascorbic acid and folic acid in this population is not surprising: their lack of ready ac¬ cess to fresh fruits and vegetables makes low intake of both nutrients likely. In contrast, their intake of thi¬ amine, riboflavin, niacin and protein appeared to be relatively high. Intake of vitamin A was reported to be low and serum concentrations were gen¬ erally lower than in the total Canadian population. Although overt signs of clinical deficiency were not seen, the dietary and serum evidence suggests that depletion of liver storage of this vitamin may be common among the Inuit. Anemia was not prevalent among either the Inuit or the general population, but the Nutrition Canada study presented ample evidence that iron depletion is relatively prevalent among segments of the general popula¬ tion and even more prevalent among the Inuit. The paper by Clow and colleagues adds another possible dimension to these nutritional observations. All too often there is a tendency to dismiss as relatively unimportant the observa¬ tion of nutrient depletion when there are no signs of the classic deficiency diseases. Concern about "subclinical malnutrition" has not often been given a high priority in health planning. At least in the case of ascorbic acid, Clow
colleagues postulate that there are secondary clinical sequelae of a nu¬ trient deficiency that are not sought in a conventional nutrition survey. One must ask whether among this popula¬ tion, and others, there are undetected sequelae of the apparent depletion of folic acid, vitamin A and iron. The authors are careful to point out that while their postulate seems to be the most reasonable explanation of their observations, the available data do not prove the postulate. Because of the potential long-term sequelae of hypertyrosinemia it is important to establish its cause in this population. If indeed it is secondary to a nutri¬ tional inadequacy, the need to correct this and other nutritional problems among the Inuit becomes even more urgent. We are prepared to spend large amounts of money in screening and treatment programs for phenylketonu¬
and
ria because of the known effects of this inborn error of metabolism. The frequency of phenylketonuria is about 1 in 10 000. The frequency of tyro¬ sinemia in the first study of Clow and colleagues was about 1500 in 10 000. Even if the probability of major se¬ quelae is these infants is low, can we afford to ignore the risks? Of great concern, then, is the au¬ thors* statement that it is difficult to acquire follow-up data that might sup¬ port or refute their postulate. When the same population was studied a year later the prevalence of hypertyrosine¬ mia was about half that initially noted. Information about changes that had occurred in this population and its health services during that year would clarify the situation. Paired maternalinfant blood samples collected at the time of birth could be analysed to test the postulated relation between ascor¬ bic acid values in mother and infant. A double-blind supplementation trial would test the entire postulate and might provide specific evidence of the
CMA JOURNAL/OCTOBER 4, 1975/VOL. 113 601
investigated to the point that there is understandable reluctance on their part and on the government's part to agree to yet another investigation. Nevertheless, the questions now to be posed are so important, so simple to answer, and so practical in terms of immediate benefit to the Inuit that there should be no objection to seek-
ing the answers. There is a clear responsibility to determine the cause of this problem and to help the Inuit find an acceptable and effective solution.
Many of the visitors to CMA House sembled from the miscellany of cartons in Ottawa have availed themselves of in which it had been kept hitherto, and the invitation in the lobby to inspect its organization and cataloguing are some of the association's archives dis- proceeding well. This task has served played in the area adjoining the li- to heighten the realization of how many brary. Here can be found many of the and how serious are the gaps in our treasures presented by various organi- collection. Chiefly to be regretted is zations on ceremonial occasions - the lack of a representative library of silver and glass, scrolls, photographs works on medical history and partiof eminent past presidents, the first cularly Canadian medical history. minute books of executive meetings, In this country a number of valuable important numbers of the Canadian collections of such books exist, most Medical Association Journal and other of them attached to the libraries of the memorabilia. However, the archival various medical schools. Examples are material in our possession is by no the famous Osler Library at McGill means limited to this group of items. and the Ross Mitchell Room at the Admittedly the selection on view, University of Manitoba. An outstandchosen and arranged with perceptive ing store of rare medical books belongs care by that devotee of medical his- to the Academy of Medicine at Totory, Dr. A.D. Kelly, represents. the ronto, which also possesses a superb choicest pieces, but there is also much collection of medical artefacts. There that has been stored during the years are also at the present time many local in makeshift receptacles 'and relegated medical societies active in the gathering to less accessible areas of the building. of archives relating to their particular Its accumulation has been pursued district or province. It would be unrealistic for the CMA more assiduously in some periods than in others, depending on the degree of to have as its objective the duplication interest of the individuals responsible. or emulation of such collections as It has to be confessed that there are these. However, in the headquarters of serious gaps and deficiencies. Most of the organization it is desirable to have the material is documentary in nature at least a library that contains those volumes that are basic to the history and we possess few artefacts. It is encouraging to be able to report of medicine in Canada. A small but that there are prospects of amendment regular flow of enquiries and requests of this somewhat unsatisfactory situa- is directed to the association for intion. Last year the past presidents of formation on medical historical matthe CMA formed a subcommittee with ters and at present questioners must Dr. Harry Roberts as chairman to ad- be referred to other sources of help. vance the interest in Canadian archives Our aim should be to provide a reand history. This group has been ex- source and reference centre in medical tremely active since its first meeting archives and history. To build up the type of library that in December 1974. A curator has been appointed on a part-time basis, the ma- is contemplated is by no means a terial in our possession has been as- simple enterprise. It is not, of course,
just a matter of purchasing what is needful. Most of the essential items are out of print and available only as they come on the market through the disposal of private collections. One other source of supply we are desirous of utilizing is our own members. We would earnestly request any of these who possess works on the history of medicine or dealing with the local or provincial medical scene to give thought to donating them to the library at CMA House. It is highly possible that some extremely important works stand on the shelves of doctors who have had their enjoyment from reading and owning them but who will be willing to part with them to their own professional organization. Old and curious medical instruments and other artefacts will be equally welcome. Donors may be assured that their gifts will be respectfully treated and their receipt will be acknowledged in the columns of the Journal. Such activity in this field as is envisaged corresponds with the upsurge in interest in the history of Canadian medicine evidenced by the large attendances at meetings of the section at the CMA annual meetings of last year and this year. The story of the contribution of *the medical profession in the early days of our country is a fascinating and inspiring one and it is right that we should become familiar with it. The CMA intends to do all in its power to promote interest in this absorbing subject and, as far as it is able, to provide the means to satisfy it.
efficacy of short-term intervention and define goals for an approach to improvement of nutritional practices over a longer period. The data required would not be extensive and the study costs would not be high. Why, then, the apparent reluctance to probe a potentially serious health problem? The Inuit have been examined and
G.H. BEATON, PH D
Professor and chairman, Department of nutrition and food science, Faculty of medicine, University of Toronto Toronto, Ont.
CMA Archives
602 CMA JOURNAL/OCTOBER 4, 1975/VOL. 113
A.W. ANDISON, MD, FRCOG, FRCS[C]
CMA House 1867 Alta Vista Dr. Ottawa, Out.
