Interesting paper just dropped - researchers have found the master switch that regulates the differences between lung cells regenerating and lung cells defending from infection.
This may have some benefits for people with COPD and other lung disorders.
So... Just on a hunch, I checked to see if lutein played a role here too.
Yep. It helps shut down C/EBP α, which is also involved in adipose cell generation alongside PPAR γ.
Here's the fun part. If you then do a search for things high in lutein and COPD - like, say, spinach - you get papers which say that spinach is super beneficial for people with COPD. They put it down to antioxidants, but in reality it's probably helping to restore healing behavior and turn off inflammation.
Parsley will likely work way better than spinach for this, but either way if you have COPD it might be worth it introducing spinach / kale / parsley smoothies into your life.
(I'm not a doctor, this is not medical advice. Follow at your own risk). Links to papers in the replies.