I have knee pain that is probably osteoarthritis and I notice that it improves quite a bit being on low-carb. I also have a hand problem that presents like arthritis and the pain from that improves as well. I've heard similar anecdotal evidence from lots of people that their joint pain eases moderately to significantly on low-carb, so this doesn't really surprise me.

However, I just always assumed that it had to do with reducing inflammation, rather than a direct pain marker. That's great news.