Lighting up a cigarette shaves years off a person’s life, shortening their lifespan by as much as a decade. However, a recent study found that quitting smoking, even later in life, can extend a person’s life expectancy by as much as eight years—depending on how early they quit.

Researchers analyzed data from several large cohort studies and national death records to estimate the effects of smoking on life expectancy for people who never smoked, those who currently smoke, and those who previously smoked. They focused on people who quit at ages ranging from 35 to 75, assessing the years of life lost due to smoking and the years gained by quitting at each age.

They found that those who continue smoking at ages 35, 45, 55, 65, or 75 could lose 9.1, 8.3, 7.3, 5.9, and 4.4 years of life, respectively, compared to people who never smoked. However, quitting smoking could save an average of 8.0, 5.6, 3.4, 1.7, and 0.7 years, depending on the age at which smoking cessation occurs. If a person quits at age 65, they have a 23.4% chance of gaining at least one extra year of life, while for someone quitting at age 75, the chance is 14.2%.

These findings suggest that while quitting earlier provides the most substantial gains in life expectancy, even those who quit later can still extend their lives. Harmful behaviors like smoking are rooted in reward-based processes. Consequently, people often engage in these behaviors in response to triggers, such as stress or social pressures. Cognitive behavioral approaches like mindfulness can help people who engage in harmful behaviors become more mindful of these triggers. Learn more in this clip featuring Dr. Ashley Mason.