Actually, it is well documented...at least in the animal world. Carnivious mammals, like cats and dogs, live an average of 8-10 years, maybe a little longer if they are pampered. Cows, horses and the like, who are total veggies, live 20-30 years, sometimes conisderably longer, if they are allowed too...meaning some meat eater does not do them in....
I don't have human statistics at my fingertips, and I don't care to go hunting for them, but we are made of the same stuff...