China
Africa
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Introduction
Published in Robert Fried, Richard M. Carlton, Flaxseed, 2023
Robert Fried, Richard M. Carlton
Thiocyanate can act as a goitrogen, meaning that it blocks the uptake of iodine by the thyroid gland. When the diet is overly rich in goitrogens, the thyroid gland swells to trap as much iodine as possible forming a goiter or lump in the neck. The Council notes, however, that there is no evidence that consuming flaxseed produces symptoms of goiter. In fact, goiter is not a health problem where iodine intake is adequate, and it is rare in North America. Goiter occurs mainly in Asia and Africa, and in 96% of cases, it is due to iodine deficiency or consumption of cassava and not to the overconsumption of known plant goitrogens. (12)
Thyroid disease
Published in Neeraj Sethi, R. James A. England, Neil de Zoysa, Head, Neck and Thyroid Surgery, 2020
In iodine-replete areas the aetiology of goitre is not fully understood, but primary factors include genetic propensity and female sex, and secondary factors include smoking, an elevated TSH and stress. In addition, dietary goitrogens including millet, selenium, cauliflower, sweet potato, cabbage, broccoli, kelp and turnip are recognised.
Drug-induced thyroid dysfunction
Published in David S. Cooper, Jennifer A. Sipos, Medical Management of Thyroid Disease, 2018
Victor Bernet, Robert C. Smallridge
The risk of hypothyroidism associated with lithium therapy is predicated on several underlying issues, including pre-existing autoimmune thyroid disease, gender predisposition, dietary iodine status, exposure to goitrogens, and duration of lithium therapy. There also appears to be an increased risk for development of lithium-related thyroid disorders with older age (44). Individuals receiving lithium who also have underlying autoimmune thyroid disease are at increased risk for developing hypothyroidism; an annual rate of 6.4% of those with positive thyroid antibodies have been found to require l-thyroxine therapy for hypothyroidism in comparison to only 0.8% for those without thyroid antibodies (45). An annual rate of hypothyroidism of 1.5% was reported in a study of 150 patients on lithium during 15 years of followup (46). Similar to the rate seen in the general population, lithium therapy is reported to have a 5:1 female:male ratio for development of hypothyroidism (45). The reported prevalence of hypothyroidism associated with lithium therapy ranges between 3.4 and 52% and appears to vary with the population being studied (45).
Clinical and ultrasound characteristics distinguishing benign and malignant thyroid nodules in Johannesburg, South Africa
Published in Journal of Endocrinology, Metabolism and Diabetes of South Africa, 2023
Kershlin Naidu, Victoria Saksenberg, Nasrin Goolam Mahyoodeen
In keeping with reports in the international literature, PTC was the most prevalent malignancy. Follicular thyroid carcinoma is commoner in iodine-deficient populations, whereas the incidence of PTC is higher in iodine-sufficient populations.41 Follicular carcinoma has been reported as more prevalent in the black South African population. A study conducted at Chris Hani Baragwanath Hospital, Soweto reported a prevalence of PTC of 67%26 versus 86.9% in this study. Kalk et al. found follicular thyroid histology in 55% of patients who were predominantly black females from rural areas of the former Transvaal. PTC predominated in urban areas irrespective of race.41 A predominance of follicular thyroid cancer was found at the Chris Hani Baragwanath Academic Hospital in Soweto,42,43 Dr George Mukhari Academic Hospital in Ga-Rankuwa44 and in other iodine-deficient regions in South Africa.41 In KwaZulu-Natal, follicular thyroid cancer predominated in African patients (68%) whereas PTC was more frequently seen in Indian patients (57%).45 It is possible that iodine deficiency could explain the predominant follicular histology in black South African populations. The effect of goitrogens, such as cassava, in this population has not been evaluated. The predominant racial groups in this study were white and Indian/Asian from urban areas, which could explain why PTC was the most prevalent malignancy.
An examination of historical control histopathology metadata from 51 Amphibian Metamorphosis Assays
Published in Critical Reviews in Toxicology, 2021
Jeffrey C. Wolf, Adriana C. Bejarano, Douglas J. Fort, James R. Wheeler
Although the OGD considers FC hypertrophy, FC hyperplasia, thyroid hypertrophy, and thyroid atrophy to be the core diagnoses of the AMA, other types of morphologic findings may be the key determinants of endocrine activity in certain studies. For example, Opitz et al. 2006 found differences in follicle size and colloid depletion to be particularly sensitive for detecting the goitrogenic effects of ethylenethiourea (ETU) in X. laevis tadpoles. However, to minimize the potential for creating false-positive or -negative outcomes, and to maintain the integrity of the historical control data, it is recommended that non-core and ad hoc diagnoses be employed sparingly and judiciously. As stated earlier, such diagnoses should be clearly definable, capable of being applied consistently, and plausibly linked to some type of pathological or physiological process.
Arecoline inhibits pineal–testis function in experimentally induced hypothyroid rats
Published in Archives of Physiology and Biochemistry, 2020
Indraneel Saha, Suman Bhusan Chakraborty, Aniruddha Chatterjee, Debajyoti Pradhan, Urmi Chatterji, B. R. Maiti
PTU, a goitrogen, is a potent antithyroid drug which inhibits both synthesis of thyroid hormones and conversion of thyroxine (T4) to its active form, triiodothyronine (T3), in peripheral tissues (Yang and Gordon 1997). Hypothyroid activity of PTU is well documented in hyperthyroid patients (Melmed et al. 2011) as well as in animal species rats, mice, house musk, shrew (Takeuchi et al. 2006, Norris and Carr 2013). PTU is known to act by inhibition of tetraiodothyronin-5-deiodinase type I and type 2, of which type 2 is predominant in human osterblasts (Morimura et al. 2005). Additionally, D2 rather D1, is responsible for the maintenance of T3 level in shrews unlike in human and rodents liver and cerebral cortex in sickness and starvation (Takeuchi et al. 2006).