A new study from researchers in China suggests quitting smoking may significantly reduce the risk of developing dementia later in life. The analysis of over 32,000 adults across 25 years found former smokers had a lower risk compared to those who continued smoking. The findings were published in the journal Neurology. During the study period, researchers documented 5,868 cases of dementia. Participants who quit during the study had a dementia risk similar to those who had never smoked or had quit earlier.
Dementia risk continued to decline the longer a person remained smoke-free, approaching that of never-smokers after about seven years. The benefits were most pronounced among those who gained little or no weight after quitting. Lead researcher Hui Chen stated, "Our findings suggest that quitting smoking may support long-term brain health, but they also highlight that what happens after quitting matters."
Harvard-trained physician Dr. Zaid Fadul, who was not involved in the study, said the findings reinforce that the brain benefits from smoking cessation at virtually any stage. "Smoking contributes to chronic inflammation, oxidative stress, and damage to blood vessels that supply the brain," he explained. Fadul emphasized it is rarely too late to quit, noting improvements in circulation, reduced inflammation, and better cardiovascular health help preserve cognitive function. He added, "Every year without tobacco is a step toward lowering future dementia risk."
The study has limitations: it identified an association, not causation, and other health, lifestyle, and environmental factors may have influenced outcomes.