OK, I'm going to jump in late here. Gluten (a wheat protein) causes inflammation (and joint pain, and stiffness). I was having joint pain, stiffness and suffered from Plantar's Faciitis (sp?) -- the heel pain upon waking or other non-activity.
I tried a gluten free diet for 45 days and never looked back. No more heel pain, joint stiffness, nothing. I used to walk like an old woman every morning. No more. A gluten free diet is a royal pain. And if you don't go totally gluten free, don't bother doing it at all. I don't miss bread all that much, but pasta! And cake! There are more and more gluten free products on the market now that are passable, but I do miss some stuff. Then I remember how stiff and sore I was, and feel (a little) better about it.
My two cents.