Why Do Japanese Live Longer?

Is it because of their diet? Is it the sake that they drink or the raw fish that they eat? Is it simply in their genes or is their land really sacred that's why the people are gifted with longer life?

I'm not really dealing with this subject on a deeper scale, I was just wondering why there are so many old people in Japan with ages that go over 100. And it's not that they are simply old, but their minds are still very lucid. It seems like it was just their bodies that have aged.

But to be frank, I don't think I would like to grow that old. I mean, to live more than a hundred years old is not something that I dream about. For me, it's not how long we lived, but it is the quality of the life we lived.

Sounds so philosophical, isn't it? Not really it just makes sense to me. Why would I want to live very long when I could just simply pass away after accomplishing all the things that I needed to do. It may sound morbid but for me, it's far from it.