Cognitive Decline and Smoking Cessation: Long-Term Benefits in Middle-Aged and Older Adults

Strategic Insights -

Researchers have shed new light on the long-term effects of smoking cessation on cognitive decline in middle-aged and older adults, suggesting that quitting smoking can lead to improved cognitive trajectories compared to continuing to smoke. A longitudinal study conducted across 12 countries and spanning 18 years of cognitive data found that participants who quit smoking during follow-up had slower rates of memory and fluency decline compared to continuing smokers. The study, published in the Lancet Healthy Longevity, provides new insights into the potential benefits of smoking cessation for older adults.

Key Takeaways:

  • The study examined cognitive decline in 9436 participants who smoked, of which 4718 (50.0%) quit smoking and were matched with an equal number of continuing smokers.
  • In the six years before smoking cessation, matched smokers who quit and continuing smokers had similar rates of memory and fluency decline.
  • In the six years following smoking cessation, smokers who quit had memory and fluency scores that declined more slowly than continuing smokers.
  • Coefficients for interaction with age at smoking cessation suggested results did not differ by age at smoking cessation.
  • Middle-aged and older smokers with initially similar cognitive trajectories had more favorable trajectories compared to continuing smokers regardless of age at cessation.

Statistics:

  • The study included data from 9436 participants who smoked, with 4718 (50.0%) smokers who quit and 4718 (50.0%) continuing smokers.
  • The study spanned 18 years of cognitive data, from 2002-2020.
  • The results showed a 0.05 SDs (95% CI 0.00-0.10, p=0.036) slower decline in memory scores for smokers who quit compared to continuing smokers in the six years following smoking cessation.
  • The study found a 0.05 SDs (95% CI 0.01-0.10, p=0.030) slower decline in fluency scores for smokers who quit compared to continuing smokers in the six years following smoking cessation.

Sources:

  • Lancet Healthy Longevity. "Cognitive decline before and after mid-to-late-life smoking cessation: a longitudinal analysis of prospective cohort studies from 12 countries." 2025:100753.
  • NewsRx. "Findings from University College London (UCL) Broaden Understanding of Geriatrics and Gerontology." Health & Medicine Week. October 31, 2025; p 1342.