diet

Dietary Recommendations
The term goitrogen is used, to describe certain foods, which have the capability to alter how the human body absorbs and processes iodine. Iodine is an essential diet staple for every person - unless told otherwise by a physician - to prevent against Hypothyroidism and other thyroid problems. The word goitrogen is derived from the word 'goiter', a condition in which the thyroid gland becomes enlarged to try and produce more thyroid hormone. Many people who have thyroid disease are able to eat goitrogen foods with no ill effects what so ever. However, there are a few who can feel a difference in their symptoms. Usually, increased symptoms are noticed later the same day or for a few days after. If the person is Hypothyroid they may notice their symptoms increasing and may possibly notice them decreasing if they are Hyperthyroid. Goitrogens are found in Broccoli, Brussel sprouts , Cabbage , Cauliflower , Kale, Kohlrabi , Mustard, Rutabaga, Turnips, Millet, Peaches, Peanuts, Radishes, Soybean and soy products, including tofu, Spinach, Strawberries, Sweet potatoes. Isoflavones (found in soy foods) appear to reduce thyroid hormone output by blocking activity of an enzyme called thyroid peroxidase. This enzyme is responsible for adding iodine onto the thyroid hormones. Cooking appears to help inactivate the goitrogenic compounds found in food. Both isoflavones and isothiocyanates (found in cruciferous vegetables) appear to be heat-sensitive, and cooking appears to lower the availability of these substances. In the case of isothiocyanates in cruciferous vegetables like broccoli, as much as one third of this goitrogenic substance may be deactivated when broccoli is boiled in water.
Soy
The effect of soy on thyroid function is currently a controversial topic.Some believe that soy increases metabolic rate and thyroid function. Several recent articles, however, have noted problems with people taking soy supplements. One study identified the mechanism of soy's effect on thyroid function. Genistein and daidzein, the isoflavones in soy, inhibited thyroid peroxidase by acting as alternative substrates (Divi et al. 1997). Soy-based infant formulas have been associated with an increased incidence of autoimmune thyroid disease and diabetes when compared with breast-fed infants (Fort et al. 1986; Fort et al. 1990). Soy supplements should be avoided by hypothyroid patients because they increase the amount of thyroxine needed to attain clinical effect (Bell et al. 2001; Jabbar et al. 2001).	Soy information Soy Protein Sucks - article Soy & Infertility

Thyroid Association of New Zealand Inc.

Dietary Recommendations