2. Warning: Kale
This one may be a bit surprising to some, given that kale is often highly touted as a superfood that can do no harm. However, according to WebMD, “in rare cases it prevents the thyroid from getting enough iodine,” it explains.
However, the source says kale (which is part of the cabbage family) shouldn’t be a problem unless you’re already getting too little iodine in your diet, and you’re also eating a lot of kale. Other types of cabbage, as well as broccoli, cauliflower, and Brussels sprouts can also have a negative impact in the same way, warns WebMD.