I once looked at conditional lifespan data given that one reached a particular age. What was interesting that for India and Mongolia, countries with very different cultures, lifestyle, diet and climate, after 75 years the remaining lifespan was the same.

Granted in both countries those who died after 75 lived presumably most of their life a traditional lifestyle with little influence of modern factors like junk food, TV at night, work stress etc. So we cannot conclude that those factors have no influence after 75th birthday. Still people should be rather skeptical about attributing to a particular factor really long life.