Which factor makes the Loma Linda community a Blue Zone?

They have a strong social network
An Adventist in Loma Linda has a strong face-to-face social network. You go to church with them, you hike with them, they're there for you and you're there for them. These are subtleties that are enormously powerful but vastly under-celebrated because there is no profit in them. If social connectedness and volunteerism were pharmaceuticals, they would be blockbuster drugs.