Carence iodée: Vers le retour des crétins des Alpes ? (If the salt loses its savor: From the smarting up of America to the dumbing down of Europe)

http://spicesandspackledotcom.files.wordpress.com/2012/10/morton-full-size.pnghttps://i0.wp.com/www3.uakron.edu/mmlab/dose/ya-20.gif[morton_salt.jpg]Vous êtes le sel de la terre. Mais si le sel perd sa saveur, avec quoi la lui rendra-t-on? Il ne sert plus qu’à être jeté dehors, et foulé aux pieds par les hommes. Jésus (Matthieu 5: 13)
La carence en iode est si facile à prévenir que c’est un crime de permettre qu’un seul enfant naisse handicapé mental pour cette raison. H.R. Labrouisse (directeur de l’UNICEF, 1978)
The idea of putting additives in salt to promote health dates back to the 1920s, when salt suppliers in the United States and Switzerland began fortifying their salt with iodine. The measure was intended to combat a condition known as “goiter” — a swelling of the thyroid, a gland that sits just in front of the windpipe. Goiters have plagued humans for at least several thousand years. As early as 2,700 B.C., Chinese emperor Shen Nung allegedly prescribed seaweed, now known to be rich in iodine, as a treatment. Although not especially painful, large goiters can interfere with breathing and swallowing. And we now know that they’re only a symptom of a much larger problem. “The goiter is the visible manifestation” of iodine deficiency, says Richard Hanneman, president of the Salt Institute in Alexandria, Va. Iodine, a purplish-brown element that is rare in Earth’s crust but common in seawater, is essential for all life. Humans need about 150 micrograms each day. Most of that gets taken up by the thyroid and is used to make hormones that regulate metabolism. If the body lacks iodine, the thyroid doesn’t have the raw materials it needs to make these hormones. To compensate, the gland begins to grow, forming a goiter. In the United States, few realized just how common goiters were until doctors began examining men drafted to serve in World War I. Simon Levin, a physician in Lake Linden, Mich., found that 30 percent had visibly swollen thyroids: Another 2 percent had goiters large enough to prevent them from serving. In fact, more men in northern Michigan were disqualified from military service because of goiters than any other medical condition. The state was in the middle of a swath of land that would become known as the “goiter belt.” Before people got iodine from salt, they got it from their food. Foods pick up iodine from the soils where they grow (or, in the case of seafood, from seawater). But the element is unevenly distributed across Earth’s landmasses. Inland areas and mountainous regions tend to have iodine-poor soil. And because historically most of the food consumed was locally grown, the inhabitants of iodine-poor regions tended to develop iodine deficiency, and goiters. Although health officials didn’t know it at the time, iodine deficiency also leads to much more serious problems. Expectant mothers who don’t get enough iodine can have children who are mentally and physically stunted — a condition known as “cretinism.” Even moderate iodine deficiency in the mother during pregnancy can reduce her child’s IQ by 10 to 15 points. Before iodized salt was introduced in 1978, the village of Jixian in northeast China was so iodine deficient, it was known locally as the “village of idiots.” Doctors had been treating iodine deficiency with iodine syrup, but health officials wanted to prevent goiters, not just treat them. Obviously going door to door with bottles of iodine syrup wasn’t going to work. They needed to find a way to mass distribute iodine that would be economical and efficient. Salt was an obvious choice — it’s cheap, it’s easy to transport, it doesn’t spoil and everyone uses it. Salt is the “food that comes closest to being universally consumed,” says Venkatesh Mannar, executive director of the Canada-based Micronutrient Initiative. And the risk of overdose is minimal because everyone eats a predictable amount, between five and 15 grams each day: The same can’t be said of other commodities, such as sugar or flour. What’s more, iodine occurs naturally in some salt deposits. In fact, until 1900, salt mined and used by residents in the Kanawha River Valley in West Virginia contained trace amounts of iodine. As a result, goiters were rare in the region. But then, the crude brown local salt was replaced with clean, processed salt mined in Ohio and Michigan. By 1922, 60 percent of schoolgirls surveyed in Charleston and Huntington, W.Va., had enlarged thyroids. Iodized salt first appeared on grocery store shelves in Switzerland in 1921 and in the United States in 1924. In Michigan alone, the prevalence of goiter dropped more than 75 percent over the next two decades. Iodized salt didn’t begin making its way into developing countries until the 1980s. With support from UNICEF and the World Health Organization, however, it spread remarkably fast. Globally, the percentage of people with access to iodized salt has climbed from 20 percent in the mid-1990s to about 70 percent today. “It’s a great public health success,” Houston says. Geotimes
More than 70 countries, including the United States and Canada, have salt iodization programs. As a result, approximately 70% of households worldwide use iodized salt, ranging from almost 90% of households in North and South America to less than 50% in Europe and the Eastern Mediterranean regions. (…) The use of iodized salt is the most widely used strategy to control iodine deficiency. Currently, about 70% of households worldwide use iodized salt, but iodine insufficiency is still prevalent in certain regions. In the European region included in WHO reports, 52% of the population has insufficient iodine intake and, according to UNICEF, only about 49% of households in Europe (outside of the Western European subregion) have access to iodized salt. Iodine insufficiency is also prevalent in Africa, Southeast Asia, and the Eastern Mediterranean WHO regions where rates of iodized salt use range from approximately 47% to 67%. Worldwide, it is estimated that about 31% of school-age children do not have access to iodized salt. NIH
While cretinism, the most extreme expression of iodine deficiency, has become very rare and even disappeared in Europe, of considerably greater concern are the more subtle degrees of mental impairment associated with iodine deficiency that lead to poor school performance, reduced intellectual ability, and impaired work capacity. For iodine-deficient communities, between 10 and 15 IQ points may be lost when compared to similar but non-iodine-deficient populations. Iodine deficiency is the world’s greatest single cause of preventable brain damage. (…) In the early 1960s, only a few countries had IDD control programmes; most of them in the United States of America and Europe. Since then, and especially over the last two decades, extraordinary progress has been achieved by increasing the number of people with access to iodized salt and reducing the rate of iodine deficiency in most parts of the world. However, this has not been the case in several industrialized countries, especially in Europe. Compared to other regions in the world, iodized salt coverage is not as high in Europe, reaching only 27% of households. In addition, there is growing evidence that iodine deficiency has reappeared in some European countries where it was thought to have been eliminated. WHOAll European countries except Iceland have experienced this health and socioeconomic scourge to a greater or lesser degree. Endemic cretinism, the most severe consequence of iodine deficiency, was extensively reported in the past, particularly from isolated and mountain- ous areas in Austria, Bulgaria, Croatia, France, Italy, Spain and Switzerland, and was so common that the term “cretin of the Alps” became part of the common vocabulary. Nevertheless, only limited attention has been paid to the public health consequences of iodine defi ciency in Europe until recently. Over a century and a half ago iodine deficiency had already been recognized. At the beginning of the 19th century, it was first suggested that the use of salt fortified with iodine would lead to good health in people living in mountainous regions. Switzerland was the first European country to introduce iodized salt on a large scale in order to eliminate iodine deficiency. After the pioneering work of Swiss doctors that demonstrated that iodine deficiency was indeed the cause of goitre, attempts began to locally iodize salt using a hand-and-shovel method. In 1922, the Swiss Goitre Commission recommended to the then 25 Swiss Cantons (provinces) that salt be iodized on a voluntary basis at a level of 3.75 mg iodine per kg salt (or 3.75 ppm). Non-iodized salt also remained available for sale. Due to the decentralized system of the Government of Switzerland the availability of iodized salt progressed slowly; the last Canton (Aargau) allowed the sale of iodized salt only in 1952. Today, over 90% of households consume iodized salt, and about 70% of the salt used in industrial food production is iodized. However, this example was not generally replicated by many other countries in Europe. In 1999, the access of iodized salt at the household level for Europe was the lowest regional average figure in the world at 27%. Because of the declining consumption of table salt, this probably did not reflect properly the access of households to salt, and consequently, potentially to iodized salt. WHO
A new study indicates that Americans gained up to 15 IQ points after the addition of iodine to salt became mandatory. In an effort to prevent goiter related to iodine deficiency, authorities ruled that iodine be added to U.S. salt products in 1924. The iodine, in addition to eliminating goiter, appears to have had an unexpected result: smarter Americans. (…) Iodine comes from food sources, and is especially abundant in seafood and foods grown in coastal areas with high levels of iodine in the soil. Mountainous and inland areas are often very low in the nutrient, meaning food grown there doesn’t have enough iodine. Today, iodine deficiency is the leading cause of preventable mental retardation in the world. The condition, known as cretinism, was also common in the U.S. until the introduction of iodized salt. Originally, U.S. authorities wanted to reduce the incidence of goiter, but research since that time has shown that iodine plays an important role in brain development, especially during gestation. The World Health Organization estimates that two billion people worldwide are at risk of iodine deficiency. And it’s not just a Third World problem – the WHO reports that only 27 per cent of households in Europe have access to iodized salt. The researchers say that iodine may also be a cause of the so-called Flynn Effect, the steady rise in IQ that’s been ongoing since the 1930s. Daily Mail
Les populations montagnardes n’ont jamais pu se procurer aisément du sel de mer en raison de son prix. Les cas de difformité et de nanisme étaient donc fréquents parmi les populations paysannes alpines. Dans les Alpes, la population isolée des vallées était beaucoup plus souvent atteinte de désordres liés à la carence en iode. Du reste, Diderot est le premier à consigner le nom de « crétin » dans son encyclopédie raisonnée des sciences, des arts et des métiers (1754). L’expression « crétin des Alpes » est usuelle. Le crétinisme est une forme de débilité mentale et de dégénérescence physique en rapport avec une insuffisance thyroïdienne.(…) Pour éviter les carences en iode, qui altèrent le système hormonal, mais aussi le développement de l’enfant, il est souvent ajouté de l’iode au sel de cuisine (sel iodé) et parfois au lait (au Royaume-Uni notamment). Cet ajout provient de recherches faites aux États-Unis au début du XXème siècle sur les liens entre « goître endémique » et carences en iode. L’enrichissemnet en iode du sel de table a été recommandé et mis en œuvre aux Etats-Unis après la première guerre mondiale, durant les décennies 1920 et 1930. En 1955, la carence en iode semblaient avoir été éliminée aux États-Unis grâce à l’utilisation domestique du sel de table (Salt Institute, 2008, cité par l’EPA6). Cependant ensuite, dans les années 1970 – et pour des raisons mal comprises (une des explications pourrait être les régimes sans sel ou peut-être des polluants de l’eau perturbateurs de l’acquisition de l’iode par la thyroïde tels que les perchlorates) – une nouvelle tendance au manque d’iode a été observée via les enquêtes épidémiologiques NHANES. Ces dernières montrent que le taux d’américains des États-Unis touchés par cette carence (définie par l’OMS comme une teneur en iode urinaire inférieure à 100µg/L) a augmenté de 1971-1974 à 1988-19947. Ce recul semble s’être ensuite stabilisé de 1988 à 1994 selon l’enquête NHANES 2001-2002 (Hollowell et al, 1998 ; Caldwell et al 2005 cité par l’EPA6) ; La teneur médiane (320 µg/L) était supérieures à 100µg/L en 1971-1974 (NHANES I), pour passer à 145 µg/L en 1988-1994 (NHANES III) et à 168 µg/L dans l’enquête NHANES 2001-2002. Dans tous les cas, les femmes étaient à peu près deux fois plus nombreuses que les hommes à être touchées par ce déficit en iode. Selon Hollowell et al. (1998) cité par l’EPA6, aux états unis « seuls » 2,6 % de la population (1,6 % chez les hommes et 3,5 % chez les femmes) étaient en 1971 – 1974 carencés avec des teneurs urinaires en iode de moins de 50 ug/L d’iode, mais le nombre de personnes carencées a plus que quadruplé, passant à 11,7 % en 1988-1994 (8,1 % des hommes et 15,1 % chez les femmes). Lors de l’étude NHANES 2001-2002, la concentration urinaire médiane était de 167,8 pour la population totale, 11 % des personnes testées présentaient encore des concentrations inférieures à 50 UI µg/L (6,7 % chez les hommes et de 15,3 % chez les femmes) (Caldwell et al. 2005 cités par l’EPA6), ce qui montre une stabilisation, mais non une situation satisfaisante (plus de 15 % des femmes sous 50µg/L et 36,6 % des femmes sous le seuil OMS des 100µg/L, seuil OMS). Wikipedia
Depuis la publication en 1985 du premier rapport traitant du statut en iode des populations européennes, la France occupe une position intermédiaire entre les pays d’Europe du nord où les apports en io de sont satisfaisants, et ceux d’Europe du sud encore marqués par une déficience modérée, à la limite de la carence résiduelle dans certaines régions d’Italie ou d’Espagne (Scriba et al . 1985). Il existe donc un risque important pour les populations exposées de ne pouvoir répondre à toute situation physiologique correspondant à une augmentation des besoins en iode (croissance, puberté, grossesse, allaitement). Tous les pays européens ont adopté des mesures de prophylaxie de la déficience en iode reposant s ur une autorisation d’enrichissement du sel en iode. Limitée dans un premier temps au seul sel à usage domestique, cette autorisation a été élargie dans quelques pays au sel alimentaire industriel entrant dans la fabrication de certains produits alimentair es, source de conflit avec les recommandations de santé publique visant à une réduction du risque d’hypertension artérielle par une diminution de la teneur en sel des aliments transformés. I.1.1 Contexte La réduction de la déficience en iode constitue l’un des 1 00 objectifs de la loi relative à la politique de santé publique avec un objectif chiffré de réduction de 20 % de la fréquence de la déficience en iode dans la population vivant en France au terme de la période 2004 – 2008 (J.O. n° 185 du 11/08/2004). L’évo lution des modes de consommation avec le développement de la restauration collective et hors foyer, et la part croissante occupée par les produits transformés ont rendu marginale l’efficacité de la salière domestique comme vecteur du sel iodé. Le sel ajouté (sel de cuisson et sel d’ajout volontaire) représente environ 20 % de l’apport total en sel (James et al. 1987), et moins de 50 % de ce sel est enrichi en iode (Comité des Salines de France 2003). Les campagnes de prévention du risque d’hypertension arté rielle engagées depuis plus de vingt ans ont conduit à diminuer la fréquence d’utilisation de la salière domestique, ainsi que les quantités ajoutées de sel. Les récentes recommandations du rapport « Sel » de l’AFSSA (AFSSA 2002) en faveur d’une réduction d es apports sodés ( – 20 % en 5 ans), notamment via de meilleures pratiques culinaires et comportementales (utilisation non systématique de la salière domestique), devraient encore réduire l’impact du sel iodé ajouté dans la prophylaxie de la déficience en io de. Les enquêtes nationales de consommation permettent aujourd’hui de disposer de données précises de consommations alimentaires individuelles des enfants et des adultes en France. Elles ont été utilisées pour des travaux de simulation nutritionnelle : si mulations d’enrichissement des aliments en vitamines et minéraux (enrichissement des produits laitiers frais en vitamine D) ou simulations de recommandations nutritionnelles. Elles devraient permettre, grâce à la réalisation d’une table de composition alim entaire en iode, de disposer d’évaluations quantitatives liées à l’enrichissement d’aliments en iode et de montrer l’absence de risque pour la population en contrôlant les risques de dépassements des limites supérieures de sécurité. (…) La mise en évidence de l’effet protecteur du se l alimentaire naturellement riche en iode sur le risque de goitre endémique repose sur les observations de J.B. Boussingault en Colombie (1833). Il faudra cependant attendre les résultats des études de Marine et Kimball (1917 – 1920) à Akron (Ohio) pour que l’action tant thérapeutique que prophylactique de l’iode soit reconnue (Marine et al . 1920). Ce n’est finalement qu’en 1922 que le sel enrichi artisanalement en iode est introduit comme mesure de santé publique dans la prévention du goitre endémique parmi la population du canton suisse d’Appenzell. Très rapidement cette – 50 – pratique s’étendra aux autres cantons de la Confédération helvétique, ainsi qu’aux pays proches (Autriche, 1923). (…) – 52 – L’accès à un sel enrichi en iode est autorisé dans tous les pays européens, et le taux moyen (étendue) d’enrichissement est de 15 – 20 mg (5 – 60 mg) par kg de sel, avec des taux très variables, de 8 – 13 mg/kg au Danemark à 40 – 70 mg/kg en Turquie (Tableau 25). L’enrichissement est volontaire et limité au sel à usage domestique dans la plupart des pays d’Europe occidentale, il n’est obligatoire que dans 10 pays, principalement d’Europe centrale. L’enrichis sement est en majorité à base d’iodure de potassium, certains états autorisant indifféremment les deux formes, iodure et iodate. L’utilisation du sel iodé par les industries agroalimentaires reste exceptionnelle. La pénétration du sel iodé est cependant tr ès variable selon les pays. Seuls 27 % des ménages européens ont accès à un sel iodé. Le pourcentage de sel iodé à usage domestique est inférieur à 5 % en Italie et en Angleterre, il atteint 45 – 50 % en France, 50 – 60 % aux USA, et dépasse 90 % en Suisse et en Autriche. (…) Le taux de pénétration du sel iodé en France (sel fin et gros sel en petits conditionnements) est en diminution constante, 55 % en 1988, 45 % en 1997. Ce taux est estimé à 47 % en 2002 (Table au 26) (Comité des Salines de France, 2003) (…) Cette ba isse du taux de pénétration est le fait de la concurrence de sels alimentaires à moindre prix et non iodés en provenance de pays voisins, du développement des ventes de sels artisanaux (non iodés) qui représentent 10 % des ventes en petits conditionnements (sels de Guérande, Noirmoutier et Ré) et d’une absence d’implication des pouvoirs publics, en particulier en direction des populations des régions les plus exposées à la déficience en iode. Les enquêtes épidémiologiques récemment conduites dans divers pa ys européens et aux Etats – Unis montrent que selon les pays, la fraction réellement ingérée de sel ne représente que 15 à 30 % du sel de cuisson utilisé pour la préparation des aliments, réduisant ainsi de façon significative la contribution du sel enrichi en iode dans la couverture des besoins en iode. Le sel iodé, après soustraction des pertes d’iode liées à l’utilisation, aux modes de préparation, de conservation et de cuisson, ne représente en fait qu’une faible fraction de l’apport total d’iode. Les re commandations du rapport « Sel » de l’Afssa (Afssa 2002) de réduire de 20 % l’apport moyen de chlorure de sodium devraient conduire les consommateurs à modifier leurs comportements, aussi bien dans la recherche des produits artisanaux ou agroalimentaires (étiquetage du NaCl), que dans les pratiques individuelles d’utilisation du sel (fréquence d’utilisation des salières individuelles et quantité de sel ajoutée). Ces recommandations devraient donc en partie atténuer les bénéfices attendus du récent avis de l’A FSSA (31 juillet 2002) modifiant la réglementation sur l’enrichissement en iode du sel de qualité alimentaire. L’efficacité du sel iodé dans la prophylaxie de la déficience en iode dans les pays européens semble le plus souvent très largement surévaluée : (1) les quantités de sel alimentaire citées dans la littérature (3 à 5 g par jour) sont très supérieures aux quantités ingérées associées aux prises alimentaires mêmes augmentées du sel de cuisson, (2) les quantités sont appliquées à la totalité de la pop ulation et non aux seuls utilisateurs, (3) la totalité du sel alimentaire à usage domestique est considérée comme enrichi en iode. En France, sous l’hypothèse d’indépendance des fréquences d’utilisation et de choix du type de sel d’ajout (iodé contre non iodé) un quart des sujets (26,4 %) utilisent quotidiennement du sel iodé (0,48 g par jour). La contribution totale du sel iodé à usage domestique est cependant légèrement sous – évaluée, le sel de cuisson n’étant pas pris en compte dans l’évaluation des appo rts en iode. Dans les pays anciennement les plus marqués par la carence en iode (Suisse, Autriche), l’iodation du sel reste un objectif prioritaire de santé publique dans la lutte contre la déficience en iode. L’efficacité du sel iodé a été régulièrement maintenue par des ajustements successifs du taux d’enrichissement aux réductions des apports sodés dans la population. En Suisse, le taux d’enrichissement en iode (mg I/kg de sel) a ainsi été successivement augmenté de 3,75 (1922), à 7,5 (1962), 15 (1980) et 20 mg/g de sel (1998). Ces progressions ont cependant été insuffisantes pour compenser les effets des importations de sel non iodé et des campagnes de réduction des apports sodés, et ont conduit à autoriser l’utilisation de sel iodé dans certains produi ts alimentaires transformés (pain, fromages, produits de charcuterie traités en salaison, conserves et plats préparés) (Als et al. 2003). En conclusion, toutes les études mettent en évidence une relation temporelle entre le début de l’introduction du sel iodé et la réduction du risque de déficience en iode dans les populations européennes. Cependant l’interprétation de l’implication du sel iodé dans les augmentations récentes de la consommation alimentaire d’iode est ambiguë en l’absence d’un cadre expérim ental. En effet, la part potentielle relative liée à l’effet propre de l’amélioration de la supplémentation individuelle par le sel iodé est difficile à distinguer des conséquences, d’une part, des évolutions des consommations alimentaires de produits natu rellement riches en iode (produits de la pêche et de l’aquaculture) et d’autre part, de l’apparition de nouvelles sources d’iode alimentaire (produits laitiers et œufs). (…) La diminution de la consommation de sel au niveau domestique et les incitations à limiter son utilisation pèsent de façon négative sur la promotion du sel iodé à usage domestique. Bien que son intérêt à long terme puisse être discuté, il est indispensable à moyen terme de favoriser les conditions d’une augmentation du taux d’utilisation (pénétration) du sel iodé dans la population, condition préalable à toute nouvelle augmentation du taux d’enrichissement. Rapport AFSSA (2005)
La carence en iode est très répandue dans le monde puisque, selon l’OMS, elle toucherait 1,5 milliards d’individus. Douze pour cent de la population mondiale présente un goître endémique et 20 millions de personnes ont un retard mental, incluant 3 millions de crétins. La carence en iode est la première cause de retard mental évitable dans les pays développés et représente donc un problème mondial de Santé Publique. L’International council for the control of iodine deficiency disorders (ICCIDD), créé en 1985, est une organisation non gouvernementale, qui promeut l’éradication de la carence en iode dans le monde. Son action conjointe avec l’UNICEF et l’OMS a contribué à diminuer la prévalence de la carence iodée à travers le monde par l’intermédiaire de programmes de supplémentation en coordination avec les autorités sanitaires de chaque pays. L’enjeu est énorme en terme de développement cognitif des populations. La solution sur le papier est simple avec la fortification en iode d’éléments-clés de l’alimentation. Cependant, les politiques sanitaires varient selon les pays et se heurtent à des problèmes de mise en place et d’accès aux aliments fortifiés. En conséquence, la carence iodée est très variable d’une région du monde à une autre ; elle serait par exemple six fois plus fréquente en Europe qu’en Amérique. En 2002, selon l’ICCIDD, 64 % des 600 millions d’Européens de l’Ouest et du Centre présentaient une carence en iode. En France, la supplémentation n’est pas obligatoire et se fait par l’intermédiaire du sel fortifié en iode. Le sel marin commun ne contient pas d’iode. À titre d’exemple, il est estimé que 46 % des foyers en France consomment du sel fortifié en iode, contre 90 % en Amérique et 27 % pour l’Europe en général. (…) Depuis 1952, en France, les autorités sanitaires ont donc recommandé la supplémentation en iode de la population via la fortification du sel de table par de l’iodure de potassium (10 à 15 mg/kg). Cette concentration en iodure est cependant considérée trop faible pour prévenir complètement la carence iodée. De plus, cette mesure n’est pas obligatoire, et ainsi seuls 46 % des foyers utilisent ce sel fortifié. L’Académie de médecine a recommandé un enrichissement en iode par iodures à la concentration de 20 mg/kg, portant sur la totalité du sel alimentaire destiné aux particuliers, collectivités et aux industries alimentaires. Chez la femme enceinte et allaitante, dans des zones géographiques à carence en iode faible ou modérée comme la nôtre, une supplémentation en iode de 100 à 150 μg/j est recommandée. John Libbey Eurotext

Et si le sel perdait sa saveur ?

A l’heure où, avec les incessantes campagnes et l’innombrable littérature en dénonçant les méfaits mais aussi la vogue des sels naturels, le sel pourrait bien disparaitre de nos tables ..

Qui se souvient, comme le rappelle une récente étude, que les Etats-Unis lui doivent un gain de 15 points de QI ?

Qui se souvient que c’est grâce à une campagne d’iodation systématique du simple sel de table à partir des années 20 qu’ils vinrent à bout de la fameuse « ceinture du goître » découverte entre les Grand Lacs et les zones isolées des montagnes ou plaines intérieures au moment du recrutement de la première Guerre mondiale ?

Mais qui se souvient dans l’Europe des « crétins des Alpes » et des « cous du Debyshire » dans les Midlands anglaises qui entre le manque d’iode et l’endogamie étaient devenus au XIXe siècle de véritables curiosités touristiques  …

Qu’avec seuls 27% des foyers ayant accès au sel iodé (46% en France), c’est justement cette zone qui est actuellement et à nouveau l’une des plus menacées, par la carence en iode ?

How adding iodine to salt made America smarter

The U.S. introduced iodized salt in 1924

A new study compares IQ results of people in iodine deficient areas before and after iodized salt

Americans born in iodine deficient areas showed an IQ increase of 15 points after 1924

Iodine deficiency causes goiter and mental and physical retardation in infants

Alex Greig

Daily Mail

24 July 2013

A new study indicates that Americans gained up to 15 IQ points after the addition of iodine to salt became mandatory.

In an effort to prevent goiter related to iodine deficiency, authorities ruled that iodine be added to U.S. salt products in 1924.

The iodine, in addition to eliminating goiter, appears to have had an unexpected result: smarter Americans.

In a report published in the National Bureau of Economic Research, James Freyer, David Weil and Dimitra Politi examined data from about two million enlistees for World War II born between 1921 and 1927, comparing the intelligence levels of those born just before 1924 and those born just after.

To do this, they looked to standardized IQ tests that each recruit took as a part of the enlistment process.

While the researchers didn’t have access to the test scores themselves, they had another way of gauging intelligence levels: smarter recruits were sent to the Air Forces, while the less intelligent ones were assigned to the Ground Forces.

Next, the economists worked out likely iodine levels in different cities and towns around America using statistics gathered after World War I on the occurrence of goiter.

Matching the recruits with their hometowns showed researchers that the men from low-iodine areas made a huge leap in IQ after the introduction of iodine.

The men born in low-iodine areas after 1924 were much more likely to get into the Air Force and had an average IQ that was 15 points above that of their slightly older comrades.

This averages out to a 3.5 point rise in IQ levels across the nation.

The World Health Organization backed up these results saying:

‘For iodine-deficient communities, between 10 and 15 IQ points may be lost when compared to similar but non-iodine-deficient populations.’

Iodine comes from food sources, and is especially abundant in seafood and foods grown in coastal areas with high levels of iodine in the soil.

Mountainous and inland areas are often very low in the nutrient, meaning food grown there doesn’t have enough iodine.

Today, iodine deficiency is the leading cause of preventable mental retardation in the world. The condition, known as cretinism, was also common in the U.S. until the introduction of iodized salt.

Originally, U.S. authorities wanted to reduce the incidence of goiter, but research since that time has shown that iodine plays an important role in brain development, especially during gestation.

The World Health Organization estimates that two billion people worldwide are at risk of iodine deficiency.

And it’s not just a Third World problem – the WHO reports that only 27 per cent of households in Europe have access to iodized salt.

The researchers say that iodine may also be a cause of the so-called Flynn Effect, the steady rise in IQ that’s been ongoing since the 1930s.

Voir encore:

In Raising the World’s I.Q., the Secret’s in the Salt

Donald G. McNeil Jr.

The New York Times

December 16, 2006

ASTANA, Kazakhstan — Valentina Sivryukova knew her public service messages were hitting the mark when she heard how one Kazakh schoolboy called another stupid. “What are you,” he sneered, “iodine-deficient or something?”

Ms. Sivryukova, president of the national confederation of Kazakh charities, was delighted. It meant that the years spent trying to raise public awareness that iodized salt prevents brain damage in infants were working. If the campaign bore fruit, Kazakhstan’s national I.Q. would be safeguarded.

In fact, Kazakhstan has become an example of how even a vast and still-developing nation like this Central Asian country can achieve a remarkable public health success. In 1999, only 29 percent of its households were using iodized salt. Now, 94 percent are. Next year, the United Nations is expected to certify it officially free of iodine deficiency disorders.

That turnabout was not easy. The Kazakh campaign had to overcome widespread suspicion of iodization, common in many places, even though putting iodine in salt, public health experts say, may be the simplest and most cost-effective health measure in the world. Each ton of salt needs about two ounces of potassium iodate, which costs about $1.15.

Worldwide, about two billion people — a third of the globe — get too little iodine, including hundreds of millions in India and China. Studies show that iodine deficiency is the leading preventable cause of mental retardation. Even moderate deficiency, especially in pregnant women and infants, lowers intelligence by 10 to 15 I.Q. points, shaving incalculable potential off a nation’s development.

The most visible and severe effects — disabling goiters, cretinism and dwarfism — affect a tiny minority, usually in mountain villages. But 16 percent of the world’s people have at least mild goiter, a swollen thyroid gland in the neck.

“Find me a mother who wouldn’t pawn her last blouse to get iodine if she understood how it would affect her fetus,” said Jack C. S. Ling, chairman of the International Council for Control of Iodine Deficiency Disorders, a committee of about 350 scientists formed in 1985 to champion iodization.

The 1990 World Summit for Children called for the elimination of iodine deficiency by 2000, and the subsequent effort was led by Professor Ling’s organization along with Unicef, the World Health Organization, Kiwanis International, the World Bank and the foreign aid agencies of Canada, Australia, the Netherlands, the United States and others.

Largely out of the public eye, they made terrific progress: 25 percent of the world’s households consumed iodized salt in 1990. Now, about 66 percent do.

But the effort has been faltering lately. When victory was not achieved by 2005, donor interest began to flag as AIDS, avian flu and other threats got more attention.

And, like all such drives, it cost more than expected. In 1990, the estimated price tag was $75 million — a bargain compared with, for example, the fight against polio, which has consumed about $4 billion.

Since then, according to David P. Haxton, the iodine council’s executive director, about $160 million has been spent, including $80 million from Kiwanis and $15 million from the Gates Foundation, along with unknown amounts spent on new equipment by salt companies.

“Very often, I’ll talk to a salt producer at a meeting, and he’ll have no idea he had this power in his product,” Mr. Haxton said. “He’ll say ‘Why didn’t you tell me? Sure, I’ll do it. I would have done it sooner.’ ”

In many places, like Japan, people get iodine from seafood, seaweed, vegetables grown in iodine-rich soil or animals that eat grass grown in that soil. But even wealthy nations, including the United States and in Europe, still need to supplement that by iodizing salt.

The cheap part, experts say, is spraying on the iodine. The expense is always for the inevitable public relations battle.

In some nations, iodization becomes tarred as a government plot to poison an essential of life — salt experts compare it to the furious opposition by 1950s conservatives to fluoridation of American water.

In others, civil libertarians demand a right to choose plain salt, with the result that the iodized kind rarely reaches the poor. Small salt makers who fear extra expense often lobby against it. So do makers of iodine pills who fear losing their market.

Rumors inevitably swirl: iodine has been blamed for AIDS, diabetes, seizures, impotence and peevishness. Iodized salt, according to different national rumor mills, will make pickled vegetables explode, ruin caviar or soften hard cheese.

Breaking down that resistance takes both money and leadership.

“For 5 cents per person per year, you can make the whole population smarter than before,” said Dr. Gerald N. Burrow, a former dean of Yale’s medical school and vice chairman of the iodine council.

“That has to be good for a country. But you need a government with the political will to do it.”

‘Scandal’ of Stunted Children

In the 1990s, when the campaign for iodization began, the world’s greatest concentration of iodine-deficient countries was in the landlocked former Soviet republics of Central Asia.

All of them — Kazakhstan, Turkmenistan, Tajikistan, Uzbekistan, Kyrghzstan — saw their economies break down with the collapse of the Soviet Union. Across the region, only 28 percent of all households used iodized salt.

“With the collapse of the system, certain babies went out with the bathwater, and iodization was one of them,” said Alexandre Zouev, chief Unicef representative in Kazakhstan.

Dr. Toregeldy Sharmanov, who was the Kazakh Republic’s health minister from 1971 to 1982, when it was in the Soviet Union, said the problem was serious even then. But he had been unable to fix it because policy was set in Moscow.

“Kazakh children were stunted compared to the same-age Russian children,” he said. “But they paid no attention. It was a scandal.”

In 1996, Unicef, which focuses on the health of children, opened its first office in Kazakhstan and arranged for a survey of 5,000 households. It found that 10 percent of the children were stunted, opening the way for international aid. (Stunting can have many causes, but iodine deficiency is a prime culprit.)

In neighboring Turkmenistan, President Saparmurat Niyazov — a despot who requires all clocks to bear his likeness and renamed the days of the week after his family — solved the problem by simply declaring plain salt illegal in 1996 and ordering shops to give each citizen 11 pounds of iodized salt a year at state expense.

In Kazakhstan, the democratic credentials of President Nursultan A. Nazarbayev, who has ruled since 1991, have come under criticism, but he does not rule by decree. “Those days are over,” said Ms. Sivryukova of the confederation of Kazakh charities. “Businesses are private now. They don’t follow the president’s orders.”

Importantly, however, the president was supportive. But even so, as soon as Parliament began debating mandatory iodization in 2002, strong lobbies formed against the measure.

The country’s biggest salt company was initially reluctant to cooperate, fearing higher costs, a Unicef report said. Cardiologists argued against iodization, fearing it would encourage people to use more salt, which can raise blood pressure. More insidious, Dr. Sharmanov said, were private companies that sold iodine pills.

“They promoted their products in the mass media, saying iodized salt was dangerous,” he said, shaking his head.

So Dr. Sharmanov, the national Health Ministry, Ms. Sivryukova and others devised a marketing campaign — much of it paid for by American taxpayers, through money given to Unicef by the United States Agency for International Development.

Comic strips starring a hooded crusader, Iodine Man, rescuing a slow-witted student from an enraged teacher were handed out across the country.

A logo was designed for food packages certified to contain iodized salt: a red dot and a curved line in a circle, meant to represent a face with a smile so big that the eyes are squeezed shut.

Also, Ms. Sivryukova’s network of local charity women stepped in. As in all ex-Soviet states, government advice is regarded with suspicion, while civic organizations have credibility.

Her volunteers approached schools, asking teachers to create dictation exercises about iodized salt and to have students bring salt from home to test it for iodine in science class.

Ms. Sivryukova described one child’s tears when he realized he was the only one in his class with noniodized salt.

The teacher, she said, reassured him that it was not his fault. “Children very quickly start telling their parents to buy the right salt,” she said.

One female volunteer went to a bus company and rerecorded its “next-stop” announcements interspersed with short plugs for iodized salt. “She had a very sexy voice, and men would tell the drivers to play it again,” Ms. Sivryukova said.

Even the former world chess champion Anatoly Karpov, who is a hero throughout the former Soviet Union for his years as champion, joined the fight. “Eat iodized salt,” he advised schoolchildren in a television appearance, “and you will grow up to be grandmasters like me.”

Mr. Karpov, in particular, handled hostile journalists adeptly, Mr. Zouev said, deflecting inquiries as to why he did not advocate letting people choose iodized or plain salt by comparing it to the right to have two taps in every home, one for clean water and one for dirty.

By late 2003, the Parliament finally made iodization mandatory.

In Aral, Mountains Made of Salt

Today in central Kazakhstan, a miniature mountain range rises over Aral, a decaying factory town on what was once the shore of the Aral Sea, a salt lake that has steadily shrunk as irrigation projects begun under Stalin drained the rivers that feed it.

Drive closer and the sharp white peaks turn out to be a small Alps of salt — the Aral Tuz Company stockpile. Salt has been dug here for centuries. Nowadays, a great rail-mounted combine chews away at a 10-foot-thick layer of salt in the old seabed, before it is towed 11 miles back to the plant, and washed and ground. Before it reaches the packaging room, as the salt falls through a chute from one conveyor belt to another, a small pump sprays iodine into the grainy white cascade. The step is so simple that, if it were not for the women in white lab coats scooping up samples, it would be missed.

The $15,000 tank and sprayer were donated by Unicef, which also used to supply the potassium iodate. Today Aral Tuz and its smaller rival, Pavlodar Salt, buy their own.

Asked about the Unicef report saying that Aral Tuz initially resisted iodization on the grounds that it would eat up 7 percent of profits, the company’s president, Ontalap Akhmetov, seemed puzzled. “I’ve only been president three years,” he said. “But that makes no sense.” The expense, he said, was minimal. “Only a few cents a ton.”

Kazakhstan was lucky. It had just the right mix of political and economic conditions for success: political support, 98 percent literacy, an economy helped along by rising prices for its oil and gas. Most important, perhaps, one company, Aral Tuz, makes 80 percent of the edible salt.

That combination is missing in many nations where iodine deficiency remains a health crisis. In nearby Pakistan, for instance, where 70 percent of households have no iodized salt, there are more than 600 small salt producers.

“If a country has a reasonably well-organized salt system and only a couple of big producers who get on the bandwagon, iodization works,” said Venkatesh Mannar, a former salt producer in India who now heads the Micronutrient Initiative in Ottawa, which seeks to fortify the foods of the world’s poor with iodine, iron and other minerals. “If there are a lot of small producers, it doesn’t.”

Now that Kazakhstan has its law, Ms. Sivryukova’s volunteers have not let up their vigilance. They help enforce it by going to markets, buying salt and testing it on the spot. The government has trained customs agents to test salt imports and fenced some areas where people dug their own salt. Children still receive booklets and instruction.

Experts agree the country is unlikely to slip back into neglect. Surveys find consumers very aware of iodine, and the red-and-white logo is such a hit that food producers have asked for permission to use it on foods with added iron or folic acid, said Dr. Sharmanov, the former Kazakh Republic health minister. And the salt is working. In the 1999 survey that found stunted children, a smaller sampling of urine from women of child-bearing age found that 60 percent had suboptimal levels of iodine.

“We just did a new study, which is not released yet,” said Dr. Feruza Ospanova, head of the nutrition academy’s laboratory. “The number was zero percent.”

Voir encore:

L’homme de Flores, peut-être un «crétin des Alpes»

Isabelle Brisson

06/03/2008

Une carence nutritionnelle en iode serait à l’origine du nanisme de cet homme préhistorique.

Les restes de l’homme de Flores (Homo floresiensis) portent les traces caractéristiques d’une insuffisance thyroïdienne causée par un déficit en iode de la mère pendant la grossesse, indique une récente étude australienne (1). Les fossiles de cet homme préhistorique de petite taille, vieux de 18 000 ans, ont été mis au jour dans la grotte de Liang Bua sur l’île de Flores (Indonésie) et décrits en 2004 comme une nouvelle espèce d’hominidé.

La carence en iode induit un déficit en hormone thyroïdienne qui aboutit au goitre et altère dans certains cas la croissance corporelle et la maturation du cerveau, causant parfois un retard mental profond. Dans le cas de l’homme de Flores, les chercheurs australiens ont trouvé les traces anatomiques de cette maladie. Il s’agit d’un creux dans le crâne situé au niveau de l’hypophyse ou «fossette pituitaire» et du doublement des racines des prémolaires inférieures. C’est ce qui a certainement interdit à l’homme de Flores de dépasser le mètre de haut en taille, indiquent les auteurs de l’étude qui ont comparé l’image de son crâne à des crânes humains actuels ayant souffert d’hypothyroïdisme. «Cette pathologie se repère en principe sur les sutures crâniennes en fonction de l’âge», confirme le professeur Philippe Chanson, endocrinologue. Les paléontologues australiens en concluent qu’ils sont en présence d’individus atteints de cette maladie et non d’une nouvelle espèce humaine.

«Ebu Gogo»

À l’appui de leur démonstration, ils s’appuient sur de vieilles légendes locales qui relatent la présence de petits ancêtres velus, appelés «Ebu Gogo». Ceux-ci vivaient dans les cavernes de l’île indonésienne, avaient des problèmes d’élocution et volaient des fruits et des légumes dans les jardins. En France nous connaissons aussi cette maladie sous le nom de «crétinisme des Alpes». Autrefois, en effet, dans les régions éloignées de la mer, les populations qui vivaient en cercles restreints et dont les individus se mariaient entre eux souffraient de carence en iode.

Deux théories scientifiques s’opposent, parfois violemment, à propos de l’homme de Flores. Les uns y voient une nouvelle espèce atteinte de nanisme insulaire, les autres considèrent qu’il s’agit d’individus mal développés ou malades. Des études génétiques pourraient peut-être trancher le débat. À condition que les échantillons ne soient pas contaminés par l’ADN des chercheurs eux-mêmes…

Voir enfin:

Salt of the Earth

The public health community employs a mineral to fight infectious disease.

Cassandra Willyard

Geotimes

June 2008

In the tiny South American nation of Guyana lives a problematic parasite called Wuchereria bancrofti. This thread-like worm hitchhikes from person to person in the bellies of mosquitoes and lodges itself in the delicate vessels of the body’s lymphatic system. There it wreaks havoc.

The lymphatic system drains and filters the body’s fluids. But when tangled nests of worms infest the vessels, fluids can’t flow properly. Instead, they pool within the body, causing an infected individual’s limbs or genitals to swell and stretch. The disease is called lymphatic filariasis, but the symptoms have their own names, such as elephantiasis or the more colloquial “Big Foot.”Filariasis not only disfigures, it also disables. Some Guyanese are unable to walk or even stand, let alone work. And then there’s the stigma that goes along with having feet so large that no shoe will fit. (Men have been known to abandon their wives for less.) “These people become total social outcasts,” says Robin Houston, an international public health consultant who has worked in Guyana. “They can’t really do anything.”

Filariasis is difficult to treat, but easy to prevent. A cheap drug called diethylcarbamazine — DEC for short — kills the worms before they can cause damage or spread. Used consistently, it can stop transmission of the parasite. Distribution, however, is a problem. Guyana’s roads can be muddy and treacherous. Moreover, even in areas where the roads are passable, the country doesn’t have enough health workers to ensure that everyone takes the medication. So instead of handing out pills, the government decided to spike the salt supply.

Whoever first said, “An ounce of prevention is worth a pound of cure,” likely wasn’t thinking of salt. Yet the saltshaker has become one of the most powerful weapons in the public health arsenal. “Salt is an ideal vehicle,” says Trevor Milner, an international public health consultant based on St. Thomas in the U.S. Virgin Islands. “It’s cheap and it’s accessible to everyone.”

An ounce of prevention

The idea of putting additives in salt to promote health dates back to the 1920s, when salt suppliers in the United States and Switzerland began fortifying their salt with iodine. The measure was intended to combat a condition known as “goiter” — a swelling of the thyroid, a gland that sits just in front of the windpipe.

Goiters have plagued humans for at least several thousand years. As early as 2,700 B.C., Chinese emperor Shen Nung allegedly prescribed seaweed, now known to be rich in iodine, as a treatment. Although not especially painful, large goiters can interfere with breathing and swallowing. And we now know that they’re only a symptom of a much larger problem. “The goiter is the visible manifestation” of iodine deficiency, says Richard Hanneman, president of the Salt Institute in Alexandria, Va.

Iodine, a purplish-brown element that is rare in Earth’s crust but common in seawater, is essential for all life. Humans need about 150 micrograms each day. Most of that gets taken up by the thyroid and is used to make hormones that regulate metabolism. If the body lacks iodine, the thyroid doesn’t have the raw materials it needs to make these hormones. To compensate, the gland begins to grow, forming a goiter.

In the United States, few realized just how common goiters were until doctors began examining men drafted to serve in World War I. Simon Levin, a physician in Lake Linden, Mich., found that 30 percent had visibly swollen thyroids: Another 2 percent had goiters large enough to prevent them from serving. In fact, more men in northern Michigan were disqualified from military service because of goiters than any other medical condition. The state was in the middle of a swath of land that would become known as the “goiter belt.”

Before people got iodine from salt, they got it from their food. Foods pick up iodine from the soils where they grow (or, in the case of seafood, from seawater). But the element is unevenly distributed across Earth’s landmasses. Inland areas and mountainous regions tend to have iodine-poor soil. And because historically most of the food consumed was locally grown, the inhabitants of iodine-poor regions tended to develop iodine deficiency, and goiters.

Although health officials didn’t know it at the time, iodine deficiency also leads to much more serious problems. Expectant mothers who don’t get enough iodine can have children who are mentally and physically stunted — a condition known as “cretinism.” Even moderate iodine deficiency in the mother during pregnancy can reduce her child’s IQ by 10 to 15 points. Before iodized salt was introduced in 1978, the village of Jixian in northeast China was so iodine deficient, it was known locally as the “village of idiots.”

Doctors had been treating iodine deficiency with iodine syrup, but health officials wanted to prevent goiters, not just treat them. Obviously going door to door with bottles of iodine syrup wasn’t going to work. They needed to find a way to mass distribute iodine that would be economical and efficient. Salt was an obvious choice — it’s cheap, it’s easy to transport, it doesn’t spoil and everyone uses it. Salt is the “food that comes closest to being universally consumed,” says Venkatesh Mannar, executive director of the Canada-based Micronutrient Initiative. And the risk of overdose is minimal because everyone eats a predictable amount, between five and 15 grams each day: The same can’t be said of other commodities, such as sugar or flour.

What’s more, iodine occurs naturally in some salt deposits. In fact, until 1900, salt mined and used by residents in the Kanawha River Valley in West Virginia contained trace amounts of iodine. As a result, goiters were rare in the region. But then, the crude brown local salt was replaced with clean, processed salt mined in Ohio and Michigan. By 1922, 60 percent of schoolgirls surveyed in Charleston and Huntington, W.Va., had enlarged thyroids.

Iodized salt first appeared on grocery store shelves in Switzerland in 1921 and in the United States in 1924. In Michigan alone, the prevalence of goiter dropped more than 75 percent over the next two decades. Iodized salt didn’t begin making its way into developing countries until the 1980s. With support from UNICEF and the World Health Organization, however, it spread remarkably fast. Globally, the percentage of people with access to iodized salt has climbed from 20 percent in the mid-1990s to about 70 percent today. “It’s a great public health success,” Houston says.

Stacking the DEC

Salt iodization paved the way for other additives. In 1955, Switzerland began adding fluoride to its salt to prevent dental cavities. Soon after, people began to experiment with more controversial, human-made additives — first, the anti-malarial medication chloroquine, and later, DEC.

Lymphatic filariasis isn’t limited to Guyana. The World Health Organization estimates that more than 120 million people worldwide are infected with Wuchereria bancrofti or one of the other two worms that cause lymphatic filariasis in Africa, South America and Asia. Of those, 40 million have been disfigured or handicapped by the disease. The goal, as outlined by the World Health Assembly in 1997, is to eliminate lymphatic filariasis by 2020 — no easy feat given that the disease persists in some of the most isolated and impoverished regions of the world.

To combat filariasis, health workers usually prescribe DEC tablets. Each year, they try to get as many people in the affected areas to take a dose of DEC (combined with another drug) as possible. But the intervention is expensive and time-consuming. Guyana doesn’t have enough health workers to carry the tablets door to door. Put the DEC in salt, however, and it distributes itself.

There are other benefits to using salt. Large doses of DEC can cause side effects in those who are infected. The medicine kills microscopic worms in the bloodstream and a massive die-off can sometimes cause memorable symptoms — headaches, fever and nausea. People who agree to take the pill one year, might not the next. “I think it’s very difficult to mobilize an entire population to take a pill once a year,” Houston says. But the dose of DEC people get in the salt is so low “that it’s not associated with the same side effects,” says Patrick Lammie, an immunologist at the Centers for Disease Control and Prevention in Atlanta, Ga.

The idea of adding DEC to salt to eliminate filariasis was the brainchild of physician Frank Hawking, father of famed astronomer Stephen Hawking. In 1967, Hawking published a paper in the Bulletin of the World Health Organization showing that DEC stays stable and potent in salt, even after being cooked. He and a colleague even tested DEC salt on mental patients and prisoners in Recife, Brazil, with good results. But it wasn’t administered on a large scale until the 1970s, when China began using it as part of a campaign to eliminate filariasis. “They were the ones that really showed that you could use this as a public health intervention,” Lammie says. “Over 200 million people in China received DEC salt.”

The results were impressive. In one county in Shandong Province, DEC salt reduced the rate of infection from 9 percent to less than 1 percent in as few as six months. After six years, doctors could not find anyone who was infected. Before the initiative, an estimated 31 million people in China were infected. As of 1994, transmission had ceased. In 2006, the World Health Organization declared China officially free of lymphatic filariasis.

But it’s unclear whether the strategy can work as well in democratic nations, Milner says. China’s situation was unique, he says. “They were very much a command and control society.” They mandated that certain regions use DEC salt rather than giving people an option. As a result, “they were able to achieve very high levels of population coverage,” Lammie says.

Success has proven more difficult to achieve in other countries, where officials must convince salt producers to make DEC salt, shopkeepers to carry it and consumers to buy it. “The question that hasn’t been fully answered is whether this kind of strategy can work in open markets,” Lammie says. Fortifying salt with an essential element is perhaps more socially acceptable than fortifying it with a drug. Guyana, which introduced DEC salt in 2003, is a test case. And things haven’t been going well.

One of the first problems arose even before DEC salt was on the shelves. Back then, most salt suppliers in Guyana sold salt in 50-kilogram bags. “The shopkeepers would parcel this out,” putting it into smaller unmarked bags, Milner says. To help prevent contamination and accidental spills, Milner and his colleagues asked the supplier to put the salt in individual labeled bags. They wanted to “upgrade the packaging and presentation,” he says. There was just one problem: On the label was a list of ingredients that included an FDA-approved anti-caking agent called potassium ferrocyanide.

The chemical had been in the salt for years, but seeing cyanide on the label gave Guyana’s residents pause. Their trepidation wasn’t all that surprising given that hundreds of followers of cult-leader Jim Jones died in Guyana in 1978 after drinking cyanide. “When they saw this name, the negative associations took place,” Milner says.

The next obstacle came soon after the salt went on sale. DEC salt should be white, but this salt had turned blue, says Nicola Butts, who works for Guyana’s Ministry of Health. It’s not clear exactly what the problem was (Milner says acidity, Butts says moisture), but according to Milner, the discolored salt was “off-putting.”

Once officials finally had coaxed people into trying DEC salt, they ran into supply problems. Guyana imports all its salt from neighboring countries. DEC salt comes from a single salt producer in Jamaica. In 2004, Hurricane Ivan destroyed the facility, halting production. By the spring of 2005, the country had run out of DEC salt. Even in fair weather, however, supplies can be unstable. “Guyana is fairly isolated in the trade networks,” Milner says. “It’s at the end of the line and transport is expensive.” Often the importers will wait until they can bring in an entire shipload of salt before restocking supplies. In the meantime, the salt supply dwindles. “In the case of the DEC salt, it ran out,” Milner says. The other importers took advantage of the opening and flooded the market with untreated salt. As of 2005, only half of the population used DEC salt and only a third of the shops carried it.

According to Butts, most of these problems have been resolved and she and her colleagues are making headway — mainly through public education. People used to think filariasis was hereditary, Butts says. “But now they know that it’s caused by a mosquito and that anybody can get it.” They are also starting to understand that DEC can protect them from the parasite. Guyana even has a catchy slogan: “Get on the BUS — Buy DEC salt, Use DEC salt and Share the information with family and friends.” And now DEC salt comes fortified with iodine and fluoride. “They are responding to it positively,” Butts says. But Guyana still has a long way to go before the disease is eradicated, as does the rest of the world.

Worth its salt?

Whether DEC salt will continue to play a role in the eradication effort is not entirely clear. Guyana is one of only a handful of countries that are using DEC salt. The fact that the strategy hasn’t been “a roaring success,” Lammie says, might mean it will be one of the last. “It’s an open question at this point whether Guyana can stick to this strategy. The fact that it hasn’t been a quick fix probably will lead other countries to be more cautious,” he says.

In retrospect, Guyana may not have been a good place to test DEC salt, Houston says. In fact, the country never even had a successful iodization program in place. “We had a number of things that conspired against us,” he says.

Despite the disappointments, Milner, Lammie and Houston argue that DEC salt can succeed. They point to China’s achievement and the mass distribution of iodized salt as proof of concept. “It seems so obvious that once you can get this thing working, it will eradicate the disease at a lower cost and in a shorter period of time,” Milner says. “The big ace card that we hold is that it works.”

Willyard is a Geotimes staff writer.

Voir enfin:

Pas de carence en iode !

Doctissimo

L’iode est un composant indispensable de notre alimentation. Et les carences sont dangereuses à plus d’un titre : du développement de l’embryon aux problèmes de thyroïde. Un dossier pour éviter les impairs et faire le plein de cet aliment santé.

Iode, un minéral indispensable

Iode minéral besoins Plus de 740 millions de personnes souffrent d’une carence en iode dans le monde. En France, les troubles thyroïdiens restent très répandus. Car certaines situations et périodes de la vie exposent particulièrement aux manques : grossesse, tabagisme, pratique d’un sport, végétarisme… Découvrez vos besoins pour mieux les combler.

Quels sont vos besoins en iode ?

Doctissimo

L’iode est un minéral indispensable à notre organisme ! Toute carence ou excès peut avoir des répercussions importantes sur la santé. Il est donc essentiel d’adapter ses apports à ses besoins, surtout dans certains cas : grossesses, sport… Petit guide pour garder la forme et éviter les coups de pompe.

L’iode entre dans la fabrication des fameuses hormones thyroïdiennes. Celles-ci sont fabriquées en permanence par notre organisme, tout au long de la vie. Des apports réguliers en iode sont ainsi indispensables pour couvrir nos besoins.

Iode à tout âge !

Bien sûr, nos besoins en iode varient. Ainsi, ils augmentent en fonction des années… Or selon l’enquête SUVIMAX, nos apports ont tendance au contraire à diminuer avec l’âge. Conséquence : les risques de carences augmentent au fil du temps, pour toucher un quart des personnes de plus de 55 ans.

Apports conseillés en Iode (en microgrammes)

Enfants de 1 à 3 ans 80

Enfants de 4 à 6 ans 90

Enfants de 6 à 9 ans 120

Enfants de 10 à 12 ans 150

Adolescents de 13 à 16 ans 150

Adolescentes de 13 à 16 ans 150

Adolescents de 16 à 19 ans 150

Adolescentes de 16-19 ans 150

Hommes adultes 150

Femmes adultes 150

Femmes enceintes (3e trimestre) 200

Femmes allaitantes 200

Hommes de plus de 65 ans 150

Femmes de plus de 55 ans 150

Personne de plus de 75 ans 150

Quels sont vos besoins ?

Les hormones thyroïdiennes, qui participent notamment au bon fonctionnement du système nerveux, sont plus sollicitées dans certains cas :

Chez les femmes enceintes et allaitantes : Hors de question d’avoir une carence en iode pendant les neuf mois de grossesse ! En effet, tout manque de ce minéral peut entraîner un retard mental chez le futur bébé. Les besoins sont ainsi plus élevés chez les futures mamans, de même que chez les femmes allaitantes. Pour bébé, il est essentiel d’éviter les carences au moins jusqu’à la diversification alimentaire.

Chez les sportifs : La pratique d’une activité physique semble particulièrement exposer les sportifs au manque d’iode. Les carences pourraient être liées aux pertes par la sueur. Il faut donc être vigilant, notamment en cas de chaleur importante.

Chez les végétariens : Les végétariens semblent particulièrement exposés au risque de carences. En effet, la viande, le poisson ou le lait sont des sources importantes d’iode. De plus, certains végétaux peuvent limiter l’absorption en iode.

Chez les fumeurs : Le tabac est un élément qui freine l’absorption de l’iode contenue dans les aliments. La cigarette serait ainsi en partie responsable de certains goitres. Ce serait particulièrement vrai chez les femmes enceintes, qui ont tout intérêt à se sevrer totalement…

En fonction des régions… Si vous habitez près de la mer, vous avez moins de chances de souffrir de carences en iode. Cela est certainement du à votre régime alimentaire, peut-être plus riche en poisson et autres crustacés. Donc pour tous ceux qui habitent dans le centre et l’Est de la France, à la montagne (même si le crétinisme à aujourd’hui disparu)… Il ne faut pas oublier d’insister sur les aliments riches en iode.

Gare aux anti-iode !

Attention, parfois les carences apparaissent alors que les apports sont suffisants : en effet, certains aliments vont empêcher le passage de l’iode dans le corps :

Le chou, le chou-fleur ;

Les navets ;

Le soja ;

Le manioc ;

Le millet.

Iode besoins santéDe manière générale, certains antioxydants, pourtant indispensables à la santé, sont nocifs à la bonne absorption de l’iode. Il s’agit notamment des flavonoïdes des fruits et légumes ou du sélénium… Attention, pas question de bannir ces aliments et nutriments de votre alimentation. Il faut simplement être vigilant et augmenter vos apports en iode en conséquence.

Pour limiter les risques de carence, une seule solution : manger varié ! Et ne pas hésiter à demander conseils à son médecin ou à un nutritionniste…

Louis Asana

Sources :

Apports nutritionnels conseillés pour la population Française, Agence Française de Sécurité Sanitaire des Aliments, 3e édition, Ed. Tec & Doc.

La carence en Iode, Mer et santé, fédération internationale de thalassothérapie, 2004

2 commentaires pour Carence iodée: Vers le retour des crétins des Alpes ? (If the salt loses its savor: From the smarting up of America to the dumbing down of Europe)

  1. […] l’heure où la science redécouvre l’importance du simple sel de table (iodé) […]

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