During a mean 11 years of follow-up, current smokers' risks for cardiovascular-, cancer-, and respiratory-related deaths were 2, 3, and 13 times higher, respectively, than never smokers' risks. Former smokers who had quit <10 years before enrollment avoided roughly 50% to 60% of these excess risks. By 30 years after quitting, excess mortality was virtually eliminated.



https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2811807