How old has your oldest relative lived to be?
Two of my great-aunts are still alive and very much kicking, well into their 90s. All the women on my grandma's side are ridiculously long-lived, mostly without medical intervention, mostly with their wits about them. I asked Grandma once what was up with that. Did they take vitamins, drink whiskey, do jumping jacks?
"We ate a lot of potatoes. Every day we ate a potato."
I went out that afternoon and bought a sack of taters. I'll happily be 90 if I'm still dancing the Charleston every weekend.