Hi well one site suggests it has several nutrients in it that help metabolism. Another site says similar things about the nutrients in it being good for it. It was also suggested that the following foods be either limited, avoided or cooked to lower the goitrogenic effects:
The brassica foods such as brussels sprouts broccoli, cabbage, rutabega, turnips, kohlrobi, cauliflower, kale. Also included were, radishes, Africa Cassava millet soy babassu fruit, pine nuts.
Personally I would limit them and cook them but still use them and I would use those foods that stimulate the thyroid such as seaweeds and use an iodine tablet now and then. Depending on how low the thyroid gets.