My grandmother always had a non-filtered Camel cig dangling from her lip if she was awake. She started the morning with a shot of Segrams whiskey in her coffee and usually finished a fifth by the end of the day. She was overweight and never did a formal exercise in her life. She made it to 93 when stomach cancer got her.
Seeing my grandfather, I have to vote for luck! He just turned 90 years old the other day. He got shot in the chest just a inch away from his heart in the second world war, also he worked most of his life in a shipyard, sawing and cutting asbestos for alot of years without a mask.
He is in quite a good health although he falls in sleep sometimes when he is sitting in his chair. (and his WWII stories are getting a little repetive by now )