My concern is the risk of goitrogens in consuming large amounts of daily cruciferous vegetables in a raw condition, and I think there's enough evidence — mechanistic, animal, and human (both controlled and case reports)-- to suggest this is a bit of a concern. (nutritionfacts.org)
Personally I believe that there is a dietary etiology, that is, some type of goitrogen in the diet. (homevet.com)
Don't Eat Raw Cruciferous Vegetables — Cruciferous vegetables like: broccoli, cauliflower, brussel sprouts, kale, collard greens, bok choy and cabbage contain goitrogens which is a chemical that suppresses the function of the thyroid gland by disrupting and blocking the enzyme that lets your thyroid use the iodine in your body to make the thyroid hormone. (floliving.com)