Quitting Smoking Earlier Went With Living Longer

CATEGORY: DISEASE PREVENTION

People who had quit smoking 10 or more years earlier lived about as long as never smokers—regaining roughly 10 of the 12 to 13 years of life that continued smoking was linked to losing—in a study of 1.48 million adults across four countries published in NEJM Evidence.¹ The differences began to appear quickly: quitting was associated with measurably lower death rates within three years.

1.48 Million Adults, 122,697 Deaths Over 15 Years

Researchers pooled four large national health studies from the United States, the United Kingdom, Norway, and Canada, covering 1.48 million adults aged 20 to 79. Each study was linked to its country’s death registry—the official government record of every death—so participants could be followed for 15 years and every death counted; 122,697 occurred. Death rates were then compared among current smokers, never smokers, and former smokers grouped by time since quitting: under 3 years, 3 to 9, or 10 or more. The comparisons were adjusted for age, education, alcohol use, and obesity.

12 Fewer Years for Women, 13 for Men

Current smokers were close to three times as likely to die during follow-up as never smokers—2.8 times as likely for women and 2.7 times for men. Averaged across the group, that meant 12 fewer years of life for women and 13 fewer for men between the ages of 40 and 79, with the excess deaths driven mostly by heart and blood-vessel disease, lung disease, and cancer.¹ That average combines about 24 to 26 years of life lost by smokers who died from smoking with no loss for those who did not.¹

Former Smokers Were 1.3 Times as Likely to Die

Former smokers overall were only 1.3 times as likely to die as never smokers—a large drop from nearly threefold. Time since quitting mattered most: quitting within the previous 3 years was associated with averting about 5 of the lost years of life, while 10 or more smoke-free years was associated with averting about 10—survival close to that of people who never smoked. Age at quitting mattered too. Among people under 40 who had quit within the previous 3 years, 95% of the extra death risk in women and 90% in men had already disappeared; even at ages 50 to 59, more than half of it was gone within that same short window. Quitting at every age studied was associated with longer survival.¹

Group Averages From Four Countries, Not Individual Guarantees

This was an observational study—it tracked what people did rather than assigning them to quit—so it shows association, not proven cause and effect. People who quit may differ in other ways from those who keep smoking. Still, the study’s size, the similar pattern across four countries, and the steady gradient—longer since quitting, closer to never-smoker survival—all point one way. The figures are also group averages, not a guarantee for any one person.

22 Cohorts Found 4% Higher Cardiovascular Death Risk

Other large studies point the same way. In more than 200,000 U.S. adults, those who quit between ages 25 and 34 lived about 10 years longer on average than those who kept smoking.² A 2025 pooling of 22 cohorts qualifies that picture: even 21 to 30 years after quitting, former smokers still had a 4% higher risk of death from heart and blood-vessel disease than never smokers.³

Key Takeaways

• In 1.48 million adults followed for 15 years, smoking was linked to 12 to 13 fewer years of life between ages 40 and 79, while quitting for 10 or more years was linked to survival close to that of never smokers.¹
• Benefits appeared early: quitting was associated with lower death rates within 3 years, and quitting within the previous 3 years was linked to averting about 5 years of the projected loss.
• Quitting before age 40 was linked to avoiding nearly all of smoking’s excess death risk, and every age group that quit showed longer survival than those who continued.

References

1. Cho ER, Brill IK, Gram IT, Brown PE, Jha P. Smoking Cessation and Short- and Longer-Term Mortality. NEJM Evidence. 2024;3(3):EVIDoa2300272. link
2. Jha P, Ramasundarahettige C, Landsman V, et al. 21st-century hazards of smoking and benefits of cessation in the United States. The New England Journal of Medicine. 2013;368(4):341–350. link.
3. Tasdighi E, Yao Z, Dardari ZA, et al. Association between cigarette smoking status, intensity, and cessation duration with long-term incidence of nine cardiovascular and mortality outcomes: the Cross-Cohort Collaboration (CCC). PLOS Medicine. 2025;22(11):e1004561. link.