Of course 'faith' can affect your health. If your 'faith' requires you to cut yourself with knives as part of religious ritual (see the Elijah/prophets of Baal story in 1 Kings) you are unlikely to escape with perfect ongoing health. If your faith requires you to fast regularly and eat frugally with much giving away to the poor, you are much less likely to suffer from obesity. And so on.

I guess the question also touches on less 'obvious' things. I'm not an expert, but I think I've read in various places that people who study mental health and well being indicate that to spend some time each day in stillness, deep breathing and contemplation is good for you. Well, that's what I do every day as a good Anglican priest: it's called 'saying the office'.

Deeper again, the brain and the body have all sorts of odd interconnections which develop in multiple and complex ways, and the disciplines of prayer, scripture, sacrament, care of the poor -- all of which are classic ways in which Christians believe they are in touch with the living Jesus Christ -- have all kinds of physical resonances which do, I believe, generally make for health -- though of course are fully incompatible, in this mysterious world the way it currently is, with sickness of all sorts. One-on-one correlations are for kindergarten theology.

Concession to new age mumbo-jumbo? Of course not. You might as well say that a love of J.S. Bach was a concession to nursery rhymes.