> I assume the secret is mostly genetics

In Atul Gawande’s Being Mortal he mentions that research shows that long life is not particularly heritable.

Lifespan genetics research is all over the place, partly because it is hard to get adequate statistics. There's currently a new preprint paper by Shenhar et al. that suggests life expectancy is actually heavily influenced by genetics if you account for the confounding factors correctly.

Many diseases that shorten lives have increased chances due to genetics from Alzheimer’s to diabetes or some heart diseases(the leading cause of death) .

While longer lives may not be directly inheritable, shorter lives absolutely can be, good genetics does play a role to living long .