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.cite journal |author=Takizawa T, Imai T, Ueda M, Onodera H, Hirose M |title=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 |journal=Cancer Sci. |volume=97 |issue=1 |pages=25–31 |year=2006 |pmid=16367917 |doi=10.1111/j.1349-7006.2005.00132.x]
* Thiocyanate overload in Central Africa, especially if also in conjunction with selenium deficiency.cite journal |author=Vanderpas J |title=Nutritional epidemiology and thyroid hormone metabolism |journal=Annu. Rev. Nutr. |volume=26 |issue= |pages=293–322 |year=2006 |pmid=16704348 |doi=10.1146/annurev.nutr.26.010506.103810] Reliance on cassava as a carbohydrate provides a source of thiocyanate in some areas.cite journal |author=Akindahunsi AA, Grissom FE, Adewusi SR, Afolabi OA, Torimiro SE, Oke OL |title=Parameters of thyroid function in the endemic goitre of Akungba and Oke-Agbe villages of Akoko area of southwestern Nigeria |journal=African journal of medicine and medical sciences |volume=27 |issue=3-4 |pages=239–42 |year=1998 |pmid=10497657 |doi=]
*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.

Goitrogenic foods

Certain foods have been identified as goitrogenic. These foods include:
*Soybeans (and soybean products such as tofu)
*Pine nuts
*Peanuts
*Millet
*Strawberries
*Pears
*Peaches
*Spinach
*Bamboo shoots
*Radishes
*Horseradish
*Vegetables in the genus "Brassica"
**Bok choy
**Broccoli
**Broccolini (Asparations)
**Brussels sprouts
**Cabbage
**Canola
**Cauliflower
**Chinese cabbage
**Choy sum
**Collard greens
**"Kai-lan" (Chinese broccoli)
**Kale
**Kohlrabi
**Mizuna
**Mustard greens
**Rapeseed ("yu choy")
**Rapini
**Rutabagas
**Tatsoi
**Turnips

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, coconut,cite journal |author=Siddhanti SR, King MW, Tove SB |title=Influence of dietary fat on factors in serum that regulate thyroid cell metabolism |journal=J. Nutr. |volume=120 |issue=11 |pages=1297–304 |year=1990 |pmid=2172489 |doi= |url=http://jn.nutrition.org/cgi/reprint/120/11/1297.pdf |format=PDF Thyroid hyperplasia has been demonstrated in mice: *cite journal |author= |title=Toxicology and carcinogenesis studies of coconut oil acid diethanolamine condensate (CAS No. 68603-42-9) in F344/N rats and B6C3F1 mice (dermal studies) |journal=National Toxicology Program technical report series |volume=479 |issue= |pages=5–226 |year=2001 |pmid=12571684 |doi=] and saturated fat. [cite web |author=Denice Moffat |title=Bad Foods for Thyroid |url=http://www.naturalhealthtechniques.com/SpecificDiseases/thyroidbadfoods.htm |accessdate=2007-10-12] Indeed some studies on rats suggest that excess caffeine in conjunction with a lack of iodine may promote the formation of thyroid cancers.cite journal |author=Son HY, Nishikawa A, Kanki K, "et al" |title=Synergistic interaction between excess caffeine and deficient iodine on the promotion of thyroid carcinogenesis in rats pretreated with N-bis(2-hydroxypropyl)nitrosamine |journal=Cancer Sci. |volume=94 |issue=4 |pages=334–7 |year=2003 |pmid=12824900 |doi=] Despite being generally a stimulant, caffeine (examples: coffee, tea, cola, chocolate) acts on thyroid function as a suppressant.cite web |url=http://www.thyroid-info.com/articles/coffeecalcium.htm |title="Caffeine, Calcium and the Thyroid Nutritional Linkages to Thyroid Disease and Thyroid Drugs"|2008-01-09= |source=www.thyroid-info.com

Footnotes

External links

* [http://www.ithyroid.com/goitrogens.htm Goitrogen page]
* [http://www.whfoods.com/genpage.php?tname=george&dbid=47 Goitrogen page] from The World's Healthiest Foods site

ee also

*Hypothyroidism
*Hyperthyroidism
*Thyroid