Plenty of people on poor diets don't get cancer. Which totally pisses of the vegan/vegetarian/organic foodies!! Even only 10% of smokers get it. And people on perfect, organic diets get cancer. The question should be - what is shortening the telomeres? One cause is stress:
"Numerous studies demonstrate links between chronic stress and indices of poor health, including risk factors for cardiovascular disease and poorer immune function. Nevertheless, the exact mechanisms of how stress gets “under the skin” remain elusive. We investigated the hypothesis that stress impacts health by modulating the rate of cellular aging. Here we provide evidence that psychological stress— both perceived stress and chronicity of stress—is significantly associated with higher oxidative stress, lower telomerase activity, and shorter telomere length, "
