Many factors affected prehistoric man’s lifespan ... lack of sanitation. predators, infectious disease, etc. Paradoxically, low carb high protein diets (meat eggs cheese etc) result in more weight loss and improved lipid profiles.
OTOH, if Rush is smoking cigarettes, then THAT is his no. 1 health risk - no doubt about it. As for exercise, I’m reminded of the words of Mark Twain (died at age 86), “Everytime I feel the urge to exercise, I sit down until it goes away.”
Cheers.