I migrated from Michigan to Japan, and the only observation I had was that my allergies had "changed". It was real severe in August when I was in Michigan, but had become severe at the end of May during my first few years in Japan.
I've been to Colorado, with the exposure to high altitude, but it didn't seem to affect me unless I was doing heavy excurtion, like running. (then I just got really winded).
Despite Japan being surrounded by salt water, I kinda think there's less of a benefit for me because of the CO2 being expelled from the automobiles and such because I live so close to the city. My visits to Nara is good in the sense that it has much cleaner air and is a little cooler.
Due to my many injuries, I have soreness whenever a big storm is coming...I can even feel it when a typhoon is coming! However, I don't take aspirins or use electrical heat pads, just knee supporters and a kind of heat pad that you adhere to your skin.