Academic literature on the topic 'Goitrogenic foods'

The best diets for Hashimoto's thyroiditis (HT) patients are the gluten-free diet, paleo diet, and vegetarian and vegan diets. Micro-nutrients to integrate in diet for patients with HT are Iodine (150-290 µg/day), Selenium (55-75 µg/day), Zinc (34-40 mg/day), Vitamin D (1500-2500 IU/day), and Vitamin B12 (2.4-2.8 µg/day). The worst foods for patients with HT that should be avoided are gluten, goitrogens, alcoholic drinks, food additives, and supplements (gums, lecithin, and coffee and fiber supplements). This chapter explores the dietary management of Hashimoto's disease.

The hypothalamus–pituitary–thyroid–periphery (HPTP) axis has been known to be a vulnerable target for environmental factors and nutritional agents for centuries. Goitrogenesis, hypo- and hyperthyroidism, tumorigenesis, and autoimmune diseases of this gland have been linked to single or combined deficiencies of several essential trace elements. Normal thyroid function depends on adequate and balanced availability of the essential trace elements iodine, selenium, iron, and the mineral zinc in the daily diet. It has been suggested that the evolution of humankind and Eve’s route of migration out of Africa, to displace the Neanderthal people and to populate the other continents, closely followed coastlines and regions with high availability of iodine, the key element required for thyroid hormone synthesis (1, 2). Involuntary or voluntary environmental or nutritional exposure to adverse factors and agents impairing thyroid hormone synthesis, secretion, binding, transport, metabolism, and action (‘goitrogens’) contributes to the development and persistence of thyroid disorders (3). Iodine deficiency, still prevalent in many regions of our world, and iodine excess (4), both of which might occur during embryonal and fetal development as well as in newborns, adolescents, and adults, provide the platform for action of adverse agents, which might be well tolerated by a normally functioning ‘quiescent’ thyroid gland with adequate iodine supply (see Chapters 3.2.3, 3.2.4). Compounds adversely affecting the HPTP axis belong to several chemical classes of food ingredients and environmental contaminants, but might also represent pharmaceutical drugs acting either directly on biomolecules comprising the HPTP axis or after modification by phase I and/or II drug metabolism (see Table 3.2.2.1). Apart from by ingestion, several agents reach their targets after inhalation (e.g. occupational exposure or smoking) or by dermal application (e.g. UV screens).

Medical geology studies the influence of geo-environmental factors on the geographical distribution of diseases of humans and animals. In the east and southern African subregion, there has been little attention paid to date on the extent to which these factors may be important in disease causation, even though developing countries in general can be shown to hold tremendous promise for specific research in this field. This chapter highlights some problems of geomedical relevance in the subregion and submits that interdisciplinary research among scientists can help provide practical solutions. The iodine deficient regions of east and southern Africa have been identified and the widespread occurrence of goiter and related conditions, collectively referred to as iodine deficiency disorders (IDD), firmly established (e.g., Davies 1994, Jooste et al. 1997). These are serious and debilitating consequences, particularly for poor populations, as the capacity of children is severely restricted and they become a burden to the family. The reported geographical distribution of endemic goiter in East Africa is shown in Figure 22.1. Many aid agencies and governments have attempted to solve the problem by increasing dietary intake of iodine via the introduction of iodized salt and iodized oil programs. Despite these interventions, IDD remain a major problem in the subregion. It is likely that IDD are multi-causal diseases involving factors such as trace element deficiencies, goiter-inducing substances in foodstuffs (known as goitrogens), and genetics (Fordyce 2000). However, geochemists have an important role to play in determining the environmental cycling of iodine and its uptake into the food chain if levels of dietary iodine are to be enhanced successfully. It has now been established that excessive fluorine (mainly in the form of fluoride) is present in parts of the hydrological system of Kenya as well as other countries in the subregion, particularly those that are associated with rift formation (Gaciri and Davies 1993). Fluoride in minor amounts (around 1.3 ppm) reduces dental decay and enhances the proper development of the bone. A similar level of fluoride intake may also be beneficial to animals.