I think it definitely have an impact on our life in general, so on our life expectancy too. Clean food, with no industrial food and as little junk food as possible is the best way to stay in good shape for long.
I heard about this island too, it's really impressive! When we look at what the inhabitants eat, it's mostly steamed veggies, white rice, and a lot of fish. There isn't much sugar in their alimentation, which is really important I think.