Goitrogen
Goitrogens are substances that suppress the function of the thyroid gland by interfering with iodine uptake, which can, as a result, cause an enlargement of the thyroid, i.e., a goitre.
Goitrogenic drugs and chemicals
Chemicals that have been shown to have goitrogenic effects include:
- Sulfadimethoxine, propylthiouracil, potassium perchlorate, and iopanoic acid.[1]
- Some oxazolidines such as goitrin.[2]
- Thiocyanate overload in Central Africa, especially if also in conjunction with selenium deficiency.[3] Reliance on cassava as a carbohydrate provides a source of thiocyanate in some areas.[4]
- Ions such as thiocyanate and perchlorate decrease iodide uptake by competitive inhibition and, as a consequence of reduced thyroxine and triiodothyronine secretion by the gland, cause an increased release of thyrotropin (by reduced negative feedback), which then stimulates the gland.
- Amiodarone inhibits peripheral conversion of thyroxine to triiodothyronine; also interferes with thyroid hormone action.
- Lithium inhibits thyroid hormone release.
- Phenobarbitone, phenytoin, carbamazepine, rifampin induce metabolic degradation of T3 and T4.
Goitrogenic foods
Certain raw foods (cooking inactivates the goitrogens) have been identified as lightly goitrogenic. These foods include:
Thyroid hyperplasia has been demonstrated in mice:[6]
Despite being generally a stimulant, caffeine (examples: coffee, tea, cola, chocolate) acts on thyroid function as a suppressant.[7] Indeed some studies on rats suggest that excess caffeine in conjunction with a lack of iodine may promote the formation of thyroid cancers.[8]
Foods stimulating thyroid tissue
Some foods and drinks have an opposite effect on the thyroid gland; that is, they stimulate thyroid function rather than suppressing it, examples being avocado and saturated fat.[9]
See also
References
- ^ Takizawa T, Imai T, Ueda M, Onodera H, Hirose M (2006). "Comparison of enhancing effects of different goitrogen treatments in combination with beta-estradiol-3-benzoate for establishing a rat two-stage thyroid carcinogenesis model to detect modifying effects of estrogenic compounds". Cancer Sci. 97 (1): 25–31. doi:10.1111/j.1349-7006.2005.00132.x. PMID 16367917.
- ^ Verhoeven DT, Verhagen H, Goldbohm RA, van den Brandt PA, van Poppel G (February 1997). "A review of mechanisms underlying anticarcinogenicity by brassica vegetables". Chem. Biol. Interact. 103 (2): 79–129. doi:10.1016/S0009-2797(96)03745-3. PMID 9055870. http://linkinghub.elsevier.com/retrieve/pii/S0009-2797(96)03745-3.
- ^ Vanderpas J (2006). "Nutritional epidemiology and thyroid hormone metabolism". Annu. Rev. Nutr. 26: 293–322. doi:10.1146/annurev.nutr.26.010506.103810. PMID 16704348.
- ^ Akindahunsi AA, Grissom FE, Adewusi SR, Afolabi OA, Torimiro SE, Oke OL (1998). "Parameters of thyroid function in the endemic goitre of Akungba and Oke-Agbe villages of Akoko area of southwestern Nigeria". African journal of medicine and medical sciences 27 (3-4): 239–42. PMID 10497657.
- ^ Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson. Robbins Basic Pathology. Philadelphia: Saunders. ISBN 1-4160-2973-7. 8th edition.
- ^ National Toxicology, Program (2001). "Toxicology and carcinogenesis studies of coconut oil acid diethanolamine condensate (CAS No. 68603-42-9) in F344/N rats and B6C3F1 mice (dermal studies)". National Toxicology Program technical report series 479: 5–226. PMID 12571684.
- ^ "Caffeine, Calcium and the Thyroid Nutritional Linkages to Thyroid Disease and Thyroid Drugs". www.thyroid-info.com. http://www.thyroid-info.com/articles/coffeecalcium.htm.
- ^ Son HY, Nishikawa A, Kanki K, et al. (2003). "Synergistic interaction between excess caffeine and deficient iodine on the promotion of thyroid carcinogenesis in rats pretreated with N-bis(2-hydroxypropyl)nitrosamine". Cancer Sci. 94 (4): 334–7. doi:10.1111/j.1349-7006.2003.tb01442.x. PMID 12824900.
- ^ Denice Moffat. "Bad Foods for Thyroid". http://www.naturalhealthtechniques.com/SpecificDiseases/thyroidbadfoods.htm. Retrieved 2007-10-12.
External links
Goitrogens-Thyroid bad foods