Mystics talk about it all the time. Some doctors are getting wise to the idea. Simply put, there is an incredibly strong link between he functioning of the mind and the physical body. But some people demand proof. For those I would direct your attention to the April 6, 2011, issue of The Journal of Neuroscience. There you'll find an article written by six researchers entitled "Brain Mechanisms Supporting the Modulation of Pain by Mindfulness Meditation." If you don't want to pay $30.00(!) just to read the article and if the abstract isn't enough, you can go to this article by Anne Harding which explains the paper.
To put it briefly, some subjects were given a pain to experience. Next,