Comparing an extremely heterogeneous country like America to ethnically monolithic countries like Finland or Japan is always an error.
Any sources to back that up? I lived in Chicago for most of my life before moving out to California. I would argue that the (over)large portions of cheese and meat diets of the midwest don't help health and life expectancy.
according to wikipedia, http://en.wikipedia.org/wiki/List_of_U.S._states_by_life_exp..., a quick glance looks pretty even, not separated out by ethnicity.
This doesn't surprise me. People knock the Midwest both out here (New York) and in California, but people out there are happy. Minneapolis, Toronto, Madison and Chicago are among the nicest cities I've seen in the world.
The winters can be very, very cold, but you get used to that. You dress for it. If the 3 worst things about the place where you live are December, January, and February, I'd say you're pretty well off. I do prefer the New York fall, though... 57 degrees and peak foliage in early November is pretty tough to beat, whereas in the midwest November is already winter.