I wouldn't call it extremely dangerous, however if you ingest a LOT of it, it will increase your estrogen levels and the thyroid will have a lot of problems functioning. You should also pay attention to goiterous vegetables that are raw. If you cook them, they do not affect the thyroid as much.
I don't have a thyroid and have been told I don't have to avoid soy or the veg at all, since my body is completely on medication so my levels do not fluxuate based on thyroid function.
Foods That Contain Goitrogens
Food items containing dietary goitrogens are as follows:
* cruciferous family: cabbage,cauliflower, broccoli, brussels sprouts, kale, mustard, radish, turnip
* soybean and soy products: tofu, tempeh, miso, soy milk, soy bread, soy nuts, soy cookies, and tamari
* fruits: peaches and strawberries
* grain: millet
* nuts: peanuts, pine nuts
How to Reduce Your Risk of Goitrogen Toxicity
The following simple steps can minimize your risks:
1. Eat a varied diet for each meal. For instance, do not eat two or more cruciferous in one meal daily. Include, other fruits, vegetables, meats, whole grains, etc. in your diet.
2. Chopping, washing, and cooking vegetables inactivates heat-sensitive goitrogenic substances.
3. Consume goitrogenic foods in smaller amounts such as 1/2 cup portions.
Vegetables from the cabbage family, soy bean and soy bean products, and other potentially goiter-causing foods are inherently "healthy" food items. By following the above strategies, they can remain an integral part of your diet.
http://nutrition.suite101.com/articl...rcausing_foods