East Africa: Double Tragedy for Emigrants

By Henry Neondo

 Over the years, this phenomenon has been explained to be due to cultural shocks. However new evidence by researchers from the Norwegian University of Science and Technology, Trondheim sheds in new lights that have hitherto escaped policy makers.

 According to Karl Erik Zachariassen of the Laboratory of Ecophysiology and Toxicology, Department of Biology, Norwegian University of Science and Technology, and Trond Peder Flaten of the Department of Chemistry, the psychotic causes may be due to a condition called medically “hyperthyroidism”---- a persistent elevation of the blood levels of the thyroxin hormones T3 and T4, which are produced in the thyroid gland. And hyperthyroidism is associated with fluoride.

  “Large areas in East Africa are notorious for high natural concentrations  of fluoride in water and plants”, say the researchers.

 “When people from such areas arrive in a low-fluoride area, their elevated capacity to produce thyroid hormones may lead to hyperthyroidism and subsequently to psychosis”, say the two.

 Their study discounts age-old reasons given for East African patients admitted for mental illnesses in Scandinavian hospitals. According to their study, asylum seekers and immigrants in Scandinavia are admitted to mental hospitals for psychotic disorders up to ten times more frequently than native Scandinavians.

 The authors say the high frequency of psychosis among immigrants is usually explained as a result of traumatic experiences in their countries of origin, problems with adapting to a new culture, and the fact that immigrants are often socially underprivileged.

 The frequency of psychotic disorders seems to be particularly high among immigrants from East Africa, and in this group of immigrants it seems particularly common to explain psychotic behaviour as a result of cultural collision and problems with social adaptation.

 Explaining the linkages between high frequency of psychosis among East Africans in Scandinavia and hyperthyroidism the two researchers say fluoride inhibits the production of thyroid hormones and to maintain normal thyroxin levels the body increases the capacity for thyroxin production.

 Goitre is caused by such a compensatory mechanism, and endemic goitre is widespread in many high-fluoride areas, even where dietary access to iodine is adequate.   

 However, some studies but not all indicate that the high frequency of mental disorders is not seen in second generation immigrants, who often have the same social standing as their parents.

Hence, although social factors are likely to be of importance, there may also be other causes. In breaking to tradition, the authors put forward the hypothesis that hyperthyroidism, caused by fluoride exposure in the asylums’ home country, is the cause of psychosis among immigrants from East Africa and other high-fluoride regions.

 These hormones are notable for their high content of iodine; three atoms in each molecule of T3 and four in T4. Via a negative feedback mechanism the function of the thyroid gland is controlled by the thyroid stimulating hormone (TSH) from the pituitary gland.

 A suboptimal blood level of thyroid hormones stimulates the release of TSH, which in turn stimulates the thyroid gland to produce more of its hormones.

 A chronic deficit of iodine causes a permanent reduction in the levels of thyroid hormones in the blood, a condition known as hypothyroidism.

 The resulting elevated level of TSH will increase the capacity of the thyroid gland to produce thyroxin, and sometimes also cause the thyroid gland to develop goitre.

 If a person with an elevated capacity for production of thyroid hormones experiences an increased dietary intake of iodine, the thyroid gland will produce increased amounts of thyroid hormones, sometimes resulting in a shift from a hypothyroid to a hyperthyroid condition.

 An elevated capacity for thyroxin production and hyperthyroidism may occur even without a manifest goitre.

 Hyperthyroidism is characterized by a number of physiological disturbances, including mental disorders. Some hyperthyroid patients develop behavioural problems, paranoia and an explosive temper.

 In spite of the characteristic and often dramatic symptoms, such a psychotic disturbance may be present for years without being properly diagnosed.

 The consequences can be tragic, involving for example broken marriages and serious violent crime.

 A high frequency of hyperthyroidism among immigrants from East Africa could be related to the chemical environment in their home countries. Large parts of East Africa are naturally very rich in fluoride, and local water sources frequently contain as much as 10 ppm and sometimes up to 40 ppm of fluoride.

 Fluoride is ingested especially via drinking water, but also via tea, fruits and vegetables.

 While optimal water levels of fluoride (about 1 ppm) result in a good dental health, higher water levels as well as contribution from other sources, often cause dental fluorosis.

 The brown-spotted teeth that are characteristic of dental fluorosis occur very frequently in Kenyans, particularly residents of  Central Kenya. A substantial amount of evidence indicates that fluoride affects the thyroid gland, and a high-fluoride intake may have similar effects as an iodine deficit.

 Many independent investigators have published experimental data suggesting that fluoride reduces the production of thyroid hormones, and epidemiological data indicate a relation between high dietary fluoride intake and goitre.

Fluoride has even been used successfully to treat hyperthyroidism.

Hence, a high intake of fluoride may cause hypothyroidism and goitre in spite of an adequate intake of iodine.

 The body responds by increasing the capacity to produce thyroid hormones, and due to this compensation people may have normal levels of thyroid hormones in spite of a permanent presence of inhibitory fluoride.

 Several mechanisms have been proposed to explain the inhibitory effect of fluoride on thyroid hormones. The mechanism that has received most attention is related to the chemical similarity between fluorine and iodine. The elements are in the same group in the periodic table, but fluorine is the smallest and most reactive element. Fluoride may thus cause a competitive inhibition of the uptake of iodide in the thyroid gland, and reduce the production of thyroid hormones.

 When people with a compensated fluoride-induced hypothyroidism move to a low-fluoride area, the fluoride-induced inhibition of the production of thyroid hormones ceases.

 In Scandinavia, the dietary intake of iodine is usually quite high due to iodized table salt and easy access to marine fish. Under these conditions, the elevated capacity for production of thyroid hormones may result in hyperthyroidism.

 But the two also caution that the development of hyperthyroidism is a complex phenomenon, and a number of factors are likely to be involved.

 The experimental data are somewhat contradictory, in that not all studies on the effects of fluoride in humans and experimental animals have shown a clear effect.

Many vegetables and other foodstuffs may contain a variety of goitrogenic substances that interfere with thyroid metabolism, and these substances may sometimes act in combination with fluoride in man under natural conditions, but may not be included in laboratory experiments.

 Hence, the hypothesis does not imply that everybody who moves from a high-fluoride area will develop hyperthyroidism.

 If the hypothesis is correct, people who move from a high-fluoride area to a low-fluoride area may have a physiological disposition for a hyperthyroid condition, and one may expect a substantially higher frequency of hyperthyroidism among people moving from high- to low-fluoride areas than among the native population of low-fluoride areas.

 They say the diagnosis of a hyperthyroid condition among immigrants may be complicated by several factors.

 Persons with a compensated hypothyroidism are likely to show normal levels of thyroid hormones if they are tested when they arrive in their new country, and it may take several months before the symptoms of hyperthyroidism become conspicuous.

 If this is the case, hyperthyroidism may be ruled out as a cause of their problems without conducting new thyroid hormone measurements.

 Furthermore, people with manifest hyperthyroidism may not be motivated neither for a diagnostic investigation nor for treatment.

 Any suggestion that they may suffer from a hormonal disturbance is taken as another insult.

 The two suggest that it would be useful if immigrants from high-fluoride areas were routinely made aware of the possibility of developing a hyperthyroid condition when they arrive in their new country.