We are all terminal except for the fact that our off springs are us, carrying our DNA so in effect we don't really die, life continues.
I have mentioned before about the Horizon documentary "Ghost in your genes" http://www.youtube.com/watch?v=fMxgkSgZoJs
which explains it might not be what you have done to contract a disease but what our fathers or grandfathers may have done.
As for diet the least amount of food we eat the longer we may live, but I like lots of others, am a person who wants to enjoy life, don't smoke but have drunk a hell of a lot and have enjoyed my tucker.
Haven't dodged the cancer bullet but hoping to get away with it.