I had a friend who had his thyroid removed, ye he was never informed that there were foods that he should have avoided.  As a result, when he took a liking to Bok Choy, I thought nothing of it, because neutraceutical therapies have always had a rather, let's say, shady reputation with medical authorities.  Sure, we pretty nearly all had stories about the benefits we experienced from our favorite dishes or foods and various preparation methods, and even though dieticians are schooled in dietary matters.  The very real need to warn people of dietary prohibitions that should accompany medical conditions, but no such warnings are given.  My friend continued to enjoy bok choy and thought nothing of it as problems started and continued to worsen, eventually leading to amputation, dementia, and death. Now, while I can't say the actual outcome was due to his diet, I did, one day, out of curiosity, Google bok choy and learned that thyroid patients should never eat it....