About twenty years ago a local radio station interviewed a guy who just turned 100. Other than being a little hard of hearing the guy clearly still had his mental faculties. They asked h8m his secret. Answer: 2 beers per day. Every day. No more, no less.

I also have a relative who turned 100 this year (she lives in another state and I was out of town when she came into town to celebrate her birthday). She still has her faculties and still gets around without physical assistance (no walker or wheelchair). Out of caution she takes a driving test every year. In her 99th year she told my mom that the DMV agent who administered her test told her she drives better than most of the other people he's tested over the years.