Longer-Term Benefits of Quitting
People who quit smoking before age 50 have one-half the risk of dying over the next 15 years compared to people who continue to smoke
The risk of coronary heart disease falls abruptly within months, and within 3-5 years the risk of coronary heart disease falls to a level indistinguishable from that of individuals who have never smoked. This is true no matter how long or how much one smoked.
The risk of lung cancer declines steadily, so that after 10 years the risk is 30-50% of that in continuing smokers. By 15 years, the risk of lung cancer is almost as low as if you had never smoked.