A lot of it has to do with lifestyle and environment - at the time. My parents are both very healthy, active, early/mid 70's. No meds except my Dad takes a statin - but he's always been a low healthy weight and exercises, just comes up high on cholesterol tests. Non smokers, rare with the red meat and a weekly drink at most.
They have both exceeded their parents by decade+ measures. Both can be attributed to overall healthier lifestyle choices (which wasn't even a thing in the 40's - 60's), and simply environment. Asbestos, lead, smog, smoke, and a bunch of other things that used to be common but are now thankfully far less so.
My maternal grandmother's breakfast was "a smoke and a good cough", and she was gone at 56. I expect my Mum to sail past 86. And every time she gets a good report after doctor's visit, she sends of a check to her favorite charity.