No, Alex, I've never tried black radishes, I'm just not that trendy. I don't pay attention to what this weeks super food is that will cure the common cold, prevent cancer, improve your love life, and help you win the lottery. That's a big business, people sell a lot of column inches, get enough viewers to make money on a blog, or if they get lucky can go on a TV talk show to sell books and T-shirts. Specialty growers can get quite high prices if their specific super food catches on.
We all have different bodies so some foods may provide some specific benefits, especially if prepared a certain way. Cooking radishes does mellow them out quite a bit. Even if a certain food helped me with a specific condition there is no guarantee that it would help you. There is no doubt in my mind that certain foods can help certain people if they have certain conditions. The only way to determine that is to try it.
I have a pretty healthy digestive system. My diet consists of a lot of different things in moderation. A lot of the super foods make my diet, there are usually pretty rich in certain nutrients. But exotic trendy varieties don't generally make it. I usually grow Champion radishes, not something trendy. But I do occasionally grow something different just because it is fun, not because it is going to change civilization as I know it. Yeah, I'm in a cynical mood this morning. There is nothing wrong with trying it.