Learn more about the lasting effects of smoking on the immune system and the importance of quitting smoking for long-term health. Quitting smoking is linked to a lower risk of disease and premature death. This study reveals that smoking alters the immune system, particularly the adaptive immunity, which protects the body from infection. While innate immunity rebounds immediately after quitting smoking, adaptive immunity remains affected for years, or even decades. The sooner individuals quit smoking, the better, as the effects do wear off over time. These changes in the immune system could potentially affect individuals’ risk of infections, cancer, or autoimmune diseases. Another study found that quitting smoking was linked to a lower risk of disease and premature death, with average life expectancy returning to normal after 10 years of quitting.