Quitting smoking in middle age reduces cognitive decline

An international study reveals that people who quit smoking in middle age reduce their cognitive decline compared to those who continue to smoke.[1].

Quitting smoking in middle age may reduce cognitive decline

Researchers found that quitting smoking halved the rate of decline in verbal fluency and slowed memory loss by about 20%. These findings come from a 12-year study of 9,436 adults aged 40 to 89 in the United States, England, and ten other European countries, published in The Lancet Healthy Longevity.

After 6 years of follow-up, one in two subjects had stopped smoking, and smokers and ex-smokers were matched according to their initial cognitive scores, age, sex, education level, and country of origin. The evolution of verbal fluency and memory was followed over 12 years, with the same cognitive decline observed over 6 years in all subjects, who were initially all smokers. Then, those who had stopped smoking were compared with those who had continued smoking for 6 years.

According to lead researcher Dr. Mikaela Bloomberg of the University College London (UCL) Institute of Epidemiology and Healthcare, these results confirm that " It's never too late to quit smoking ", adding that " This could strongly motivate middle-aged and older adults, who are less likely to attempt to quit than younger generations. " However, Professor Andrew Steptoe, co-author and member of the same Institute, warned that " Further research directly addressing dementia is needed to confirm these findings. »[2].

Long-term measurable cognitive benefits

The researchers compared the cognitive abilities of smokers who quit and those who continued to smoke. While their performance and decline were similar during the initial six-year phase of the study, ex-smokers showed less decline over the six-year follow-up.

The team concludes that individuals who quit smoking have a more favorable cognitive trajectory than persistent smokers, suggesting the importance of quitting smoking even at an advanced age to preserve brain health.

The team found that while previous studies have shown short-term cognitive improvements after quitting smoking, this is the first to confirm long-term benefits in middle-aged and older people who have quit smoking.

Smoking is already recognized as one of 14 risk factors for dementia identified by a commission of experts convened by The Lancet. Other factors include depression, excessive alcohol consumption, high cholesterol, and hearing loss.

A call to strengthen prevention and support

Public health experts point out that these findings strengthen evidence that adopting a healthier lifestyle – quitting smoking, exercising, limiting alcohol and eating a balanced diet – can reduce the risk of dementia.

Professor Paresh Malhotra, Group Leader at the UK Institute of Dementia Research's Centre for Care Research and Technology and Head of the Division of Neurology at Imperial College London, said: " It's increasingly clear that what's good for your heart and blood vessels is good for your brain and thinking. ".

Smoking actually contributes to neurodegeneration by impairing cerebral blood flow, causing chronic inflammation, and directly damaging nerve cells.

For Action on Smoking and Health (ASH), these data highlight the importance of sustained investment in smoking cessation services. In September 2025, approximately 35% of smokers in England attempted to quit, and nearly 29% of them succeeded, a success rate almost double that observed in 2007.

Responding to the findings of the UCL study, Dr. Julia Dudley, Head of Research at Alzheimer's Research UK, said: " Smoking is linked to multiple serious health problems, including cancer, heart disease, and dementia, particularly Alzheimer's disease and vascular dementia. […] Quitting smoking can significantly reduce the risk of developing these diseases. As this is an observational study, it only suggests a link between cognitive decline and smoking cessation. […] Further research is needed to understand whether other factors, such as demographic differences, socioeconomic background, or alcohol consumption, contributed to the differences. Tracking other cognitive measures, such as problem-solving, would also provide a more accurate picture of the benefits of quitting smoking. »[3].

Dr. Bloomberg clarifies that " As policymakers face the challenges of an aging population, these findings provide yet another reason to invest in tobacco control. ".

Earlier this month, another study provided further evidence that smoking affects all generations, suggesting that Children whose fathers smoked as teenagers may age faster.

©Generation Without Tobacco

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[1]Bloomberg, Mikaela et al., Cognitive decline before and after mid-to-late-life smoking cessation: a longitudinal analysis of prospective cohort studies from 12 countries, The Lancet Healthy Longevity, published October 13, 2025, accessed October 14, 2025

[2]Moon Ji-yeon, Quitting Smoking After 50 Slows Cognitive Decline, Study Finds, The Chosun Daily, published October 14, 2025, accessed the same day

[3]Neil Shaw, Quitting one thing, at any age, slows onset of dementia, study suggests, Wales Online, published 14 October 2025, accessed the same day

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