Lots of things are possible. My adoptive mom is 82 years old and has a fantastic figure. She was an acrobat and gymnast in her youth, and has, to all visible appearances, remained a hottie right up until a few years ago (and to some old dudes, she's still a hottie).
However, she has Type I diabetes, congestive heart failure, high blood pressure, and terrible arthritis. She's had four major surgeries throughout her adult life, each one removing a major organ or part of a major organ. For the last 20 years, she's been on a long list of medications.
But she looks great, and she's 82. (Not only that, I grew up under her domestic and culinary regimen, and I didn't end up looking nearly as hot as she did, to put it mildly, lol.) People vary, and some people are like a Timex; they can take a licking and keep on ticking.
ETA: I didn't want to say this because it's been said so often here before, but after hitting "post" I felt oddly remiss, so here it is: Even a raw vegan diet probably represents a net improvement on the SAD.