I too am a member of the growing ranks of asthmatics in our country. I
still take my meds, but since being paleo I've found that I can greatly
decrease them...I take half the steroids I used to and I've reduced
having to use a rescue inhaler by around two thirds.
It takes time though. I didn't notice a big change until a couple of
months of following  the paleo lifestyle rigorously. Avoiding all those
alien proteins I think pays off and reduces the "toxic overhead" so the
body can get to work healing and rebalancing. My body lets me know in no
uncertain terms when I've fallen off the wagon...the asthma comes back
almost overnight with a vengance. My experience of  course is purely
anecdotal.