this is a good post man, but IMO the single most important factor in longevity is GENETICS
my grandfather is 93 years old, and he smokes a pack a day and drinks jack most every goddamn single day, and my great-grandmother lived to be 97 also smoking nearly a pack a day and eating a pint of ice cream and other such "healthly" foods on a daily basis, and she was also a rather large woman of 5'8" and over 200 pounds, and my uncles used to call her "Big Woman"
Yes, genes. Genetic predisposition to whatever, heart, liver or kidney probs
Another thing, is guys like scott, oliva, arnold were huge abusers of orals, and did whatever they could get hands on, BUT, they went off, and got smaller in off season.
They gave their bodies, organs, muscles, tendons, skeletal structure a break by going off and getting lighter, leading "normal" lives for a while
The only exceptions to this in modern times are kevin, melvin