The article isn't making any claims about retiring to Manhattan causing increased lifespan. It isn't even intended as a scientific article at all. I suspect man

The article isn't making any claims about retiring to Manhattan causing increased lifespan. It isn't even intended as a scientific article at all. I suspect many here only read the headline? It's one man's personal essay on their decision to retire to Manhattan and their enjoyment of it. [Tl;dr: The use of "long life" in the title (probably not even chosen by the author) is figurative, not literal.]