Smoking, Parkinson’s Disease, and Mortality: A Complex Relationship

A large-scale study from South Korea has revealed a paradoxical relationship between smoking, Parkinson’s disease (PD), and mortality. Even as current smoking is associated with a lower risk of developing Parkinson’s, quitting smoking is linked to a lower risk of death overall. This research, published in Neurology® on February 25, 2026, underscores the complex interplay between lifestyle factors and neurodegenerative diseases.

The Korean Study: Key Findings

Researchers at Eulji University School of Medicine in Seoul followed over 410,000 smokers for an average of nine years. Participants, predominantly men (93.5%) with an average age of 52, underwent regular health screenings and reported their smoking habits. The study categorized participants into four groups: persistent smokers, relapsed smokers, recent quitters, and long-term quitters.

Over the course of the study, 1,794 individuals (0.44%) developed Parkinson’s disease. The incidence rates were as follows:

• Persistent Smokers: 0.33%
• Relapsed Smokers: 0.41%
• Recent Quitters: 0.67%
• Long-Term Quitters: 0.71%

After adjusting for factors like income, alcohol consumption, physical activity, and existing health conditions, both recent and long-term quitters showed a 60-61% higher risk of Parkinson’s disease compared to persistent smokers.

Quitting Smoking: A Benefit for Overall Survival

Despite the increased risk of Parkinson’s among former smokers, the study found a significant benefit in terms of overall mortality. During the study period, 31,203 deaths occurred:

• Persistent Smokers: 7.24%
• Relapsed Smokers: 8.09%
• Recent Quitters: 8.76%
• Long-Term Quitters: 7.91%

After adjustment, long-term quitters had a 17% lower risk of death, and recent quitters a 3% lower risk, compared to persistent smokers.

The Paradox and Potential Explanations

Study author Jun-Hyuk Lee, MD, PhD, emphasized that the health risks of smoking far outweigh any potential protective effect against Parkinson’s disease. “The serious health risks of smoking cannot be ignored, as it remains a major cause of preventable death and contributes to heart disease, cancer and chronic lung disorders,” he stated, as reported by the American Academy of Neurology .

The observed paradox may be explained by the fact that many smokers die prematurely from smoking-related illnesses, such as cancer or cardiovascular disease, before reaching the age where Parkinson’s disease typically develops. Research suggests that smokers may as well have different genetic predispositions or other lifestyle factors that influence their risk of both smoking and Parkinson’s disease.

Biological Mechanisms Under Investigation

Researchers are exploring potential biological mechanisms that could explain the link between smoking and Parkinson’s disease. Some studies suggest that nicotine and other components of tobacco may have neuroprotective effects. However, Dr. Lee notes that the lower risk appears to be more strongly associated with current smoking status than with the total duration of smoking, suggesting a need for research into treatments that could mimic these effects without the harmful consequences of cigarette smoke.

Important Considerations

It’s crucial to remember that this study is observational and does not prove a causal relationship between smoking and Parkinson’s disease. The study population was primarily composed of South Korean men, which may limit the generalizability of the findings. The data relied on self-reporting, which can be subject to inaccuracies.

Key Takeaways

• Current smoking is associated with a lower risk of developing Parkinson’s disease.
• Quitting smoking is associated with a lower risk of overall mortality.
• The health risks of smoking far outweigh any potential benefits.
• Further research is needed to understand the complex relationship between smoking, Parkinson’s disease, and mortality.

While the link between smoking and Parkinson’s disease remains a subject of ongoing research, the overwhelming evidence underscores the importance of avoiding tobacco use for overall health and well-being. Quitting smoking remains one of the most impactful steps individuals can seize to improve their long-term health outcomes.