Study Shows Association Between Current Smoking and Lower Risk for Parkinson Disease

TUESDAY, March 3, 2026 (HealthDay News) — Current smoking is associated with a lower risk of Parkinson disease, while recent and sustained quitters have lower risks for all-cause mortality, according to a study published online Feb. 25 in Neurology.

Sung-Ho Ahn, from the Yonsei University College of Medicine in Seoul, South Korea, and colleagues conducted a large-scale retrospective cohort study involving current smokers aged 40 years or older to examine the association between longitudinal changes in smoking status and risks for PD and all-cause mortality. Participants were categorized into persistent smokers, recent quitters, sustained quitters, and relapsed smokers.

Data were included for 410,489 eligible participants. The researchers found that persistent smokers had the lowest risk of PD during a median 9.1-year follow-up. Higher risks of PD were seen for recent quitters and sustained quitters compared with persistent smokers (subdistribution hazard ratios [95 percent confidence intervals], 1.60 [1.41 to 1.82] and 1.61 [1.42 to 1.81], respectively); no significant difference was seen for relapsed smokers versus persistent smokers (subdistribution hazard ratio, 1.05; 95 percent confidence interval, 0.87 to 1.28). Recent and sustained quitters had 3 and 17 percent lower risks of all-cause mortality, respectively, compared with persistent smokers, while no significant difference was seen for relapsed smokers.

“Our study suggests a lower risk of Parkinson”s is not necessarily associated with how long someone smokes, but rather if they are currently smoking,” coauthor Jun-Hyuk Lee, M.D., Ph.D., from the Eulji University School of Medicine in Seoul, South Korea, said in a statement. “Future studies are needed to better understand which components of smoking contribute to the reduced risk, and to develop safe and targeted therapies that replicate the effects of smoking for Parkinson”s without the harmful health consequences.”

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