I've lived in cities most of my life till we moved to a pretty green and semi-rural area near a town of just 10,000, some 10 years ago. Even though I am older (mid-50's) now than when I was a city dweller, I feel healthier and more balanced than I did at 35... and certainly less stressed. Of course, I'm just "one data point" but I feel there's a lot to the points outlined here.

Long before living in more natural surroundings, I always used to characterize my spirituality as "Nature is my Church." On reflection, I think there's more to that than merely a clever saying.