It is also a risk factor for new cases of asthma in children who have not previously shown symptoms. This belief is well-founded. Scientific evidence overwhelmingly supports the position that quitting smoking is the single most effective thing that smokers can do to enhance the quality and length of their lives. Compared to continuing smokers, people who have quit smoking have a reduced risk of lung cancer, other cancers, heart attack, stroke, chronic lung disease and other conditions caused by smoking. The health benefits of quitting are experienced by all smokers, men and women, young and old, those who are well and those who already have smoking-related disease.
Former smokers live longer than continuing smokers.
Those who quit before the age of 50 have only half the risk of dying in the next 15 years compared with those who continue to smoke. The excess risk that smokers have of dying from this disease is reduced by half after only one year of abstinence, and it continues to decline gradually thereafter. About 15 years after quitting the risk is close to that of persons who have never smoked. For lung cancer, after 10 years of abstinence former smokers have about half the risk of dying compared to continuing smokers. Women who stop smoking before pregnancy or early in pregnancy reduce their risk of having a low birthweight baby and experiencing other problems in pregnancy.