I'll do more research from home, but I just heard about it at lunch, and I'm curious.
(Edit): I learned more at the Noni Juice site. It looks a bit pricey.
One of my coworkers is a distributor for the stuff, and apparently another coworker has been drinking the juice since early May, with noticeable results. I've noticed the difference. She can walk much faster now than she used to be able to, and she looks a lot more comfortable doing it. There's no way to verify that the noni juice is what did it, but I have to say, I'm impressed.