I'd say it's in the persons genes that allow them to live that long. A long with eating healthy, not smoking, getting plenty of exercise and keeping active.
Ever hear the saying, when you quit working that's when you die?
I guess there is some truth to that as most people who stop working and move there self into a retirement community or nursing facility end up dying soon after.
Another thing, Keeping an active mind has been known to prevent getting alzheimer's disease.