DNA has minimal and maybe no impact on how long you live. In this 400 million person study, genetics may at best account for 7 percent or less impact on longevity. "Heredity made me do it" is no more sophisticated than any other fatalistic or deterministic sentiment through history. And this landmark study can hopefully put it to rest once and for all.
As I've written about before (here, here, here, here, and here), what we keep discovering is that everything other than DNA/genetics is more causal for most health and fitness markers. The long-hoped-for "cracking of the code" with the human genome has been a continual bugbear for fatalists and the people who predicted that mapping genome would unlock all of human health and wellness. As we peel back the scientific layers, we find that the way we live directs our symbionts and epigenome in a way that is far more profound than the heredity. Forthcoming discoveries in proteome and membranome are only going to further demote the heredity herring which distracted us for so long.