Quitting Smoking in Midlife Can Match Never-Smokers in Dementia Risk
Emerging evidence suggests that giving up smoking in middle age may dramatically protect brain health. In a study involving 9,436 adults from England, the United States and 10 other European countries, those who quit smoking in midlife experienced a cognitive trajectory that, over roughly six years of follow-up, resembled that of people who had never smoked. The headline finding: quitting can slow the decline in key cognitive functions and, within a decade, bring dementia risk levels in line with those who never smoked.
How the Research Was Conducted
Researchers led by Dr. Mikaela Bloomberg from University College London tracked adults aged 40 and older who either quit smoking or continued into later life. At the outset, quitters and continuers showed comparable cognitive performance. Over the next six years, cognitive tests revealed that those who quit gained a distinct advantage: a slower rate of decline in verbal fluency and memory compared with persistent smokers. The study, published in The Lancet Healthy Longevity, notes that even after starting with similar cognitive baselines, the cessation group followed more favorable trajectories as time progressed.
Key Findings
- Quitting smoking is linked to a slower rate of cognitive decline in midlife and beyond.
- Verbal fluency declined more slowly, and memory deterioration was reduced by about 20% in quitters relative to continuing smokers.
- Within roughly 10 years of cessation, dementia risk for former smokers approached that of individuals who had never smoked.
Dr. Bloomberg emphasized that the message is hopeful: it appears never too late to quit for cognitive health. As she noted, the physical health benefits of cessation are well established, and these new findings extend those gains to brain health in later life.
The Broader Context: Smoking, Dementia Risk and Lifestyle Choices
Smoking is already recognized as one of 14 modifiable risk factors for dementia by a panel convened by The Lancet. The study adds to a growing body of evidence that healthier lifestyle choices—maintaining physical activity, eating a balanced diet, moderating alcohol intake—can collectively reduce dementia risk. Experts caution that, while the results are compelling, they do not prove causation. Socioeconomic factors and alcohol use differences between quitters and ongoing smokers could influence outcomes. Nonetheless, the research supports a clear public health message: quitting smoking may slow cognitive decline and help preserve brain health during aging.
Implications for Public Health and Policy
Experts from Alzheimer’s Society, Alzheimer’s Research UK and ASH emphasize that the findings strengthen the case for robust stop-smoking services and midlife interventions. Caroline Cerny of ASH highlighted that smoking cessation can slow harms to brain health, stressing the importance of sustained help for people attempting to quit at any age. As England reports 29% of quitters succeeding in recent months, the evidence underscores a tangible opportunity to improve cognitive outcomes on a population level through accessible cessation support and lifestyle education.
Looking Ahead
While the study centers on midlife quitting, it aligns with broader messages about dementia prevention: combat risk factors early and maintain healthy habits over time. For individuals in their 40s, 50s or beyond, cessation may offer meaningful cognitive protections. Cognitive health is increasingly framed as a lifelong investment, and quitting smoking could be a powerful, actionable step toward reducing dementia risk years down the line.
