can be most probably reversed if you Avoid your triggers like smoke, perfumes, etc
Decontaminate your decor.
No pets and no carpets
BNo first hand or second hand smoking
Maintain a healthy weight
changing your diet and eating habits is a must and environment change will also definitely help
if you want specific advice how to treat Asthma naturally take a consult.
Remember You have to treat the root cause and not the symptoms.