Wow. I have some loved ones who are smokers or lapsed quitters. This is fascinating. Thanks.
This has a good rundown of helpful COPD supplements, with study references at the end:
https://www.lifeextension.com/protocols/respiratory/copd
The Vitamin C study showing it counters some iNOS activity (supports BH4):
https://www.ahajournals.org/doi/pdf/10.1161/01.res.0000049166.33035.62
A study describing superoxide dismutase (SOD) helping (along with a ton of other information):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2248324/
Another resource that appears to have collected various studies and doctor’s protocols:
http://www.medicalinsider.com/cardiac3.html
I started smoking in high school and by the time I was 38 I had a long history as a chain smoking nearly 3 pack a day guy who could not climb a flight of stairs without having to stop to catch my breath. One day in 1991 I saw a newspaper ad for hypnosis to quit smoking. Thats not the kind of thing I would usually go for but I decided the only thing I had to lose was a couple of hours and $50 for the session. I had never been hypnotized before and although it was not like I thought it would be I apparently was hypnotized because I never smoked again. I am sure that a strong desire to quit was helpful but I swear I have not even had a desire to smoke. Considering that after 25 years as a walking chimney and many unsuccessful attempts to quit I was able to do it as easily as I did must at least be partially attributed to the hypnotism. So, if you really want to quit but have not been able to I suggest looking for a hypnotist in your area who provides the service and give it a try. I can’t guarantee it will work for you but it sure did for me.