Virginia Research Day 2025

Medical Student Research Clinical

05 Smoking and Parkinson’s Disease: A Systematic Review on the Inverse Relationship of Smoking and Parkinson’s Disease

Natasha Gaito, OMS III; Sabrina Knudtson, OMS III; Dr. Charles Joseph Corresponding author: srjohnston@liberty.edu

Liberty University College of Osteopathic Medicine, Lynchburg, VA

Parkinson's disease (PD) is the second most common neurodegenerative disorder with 90,000 new patients diagnosed each year. This adult-onset neurological disorder was traditionally viewed as a motor disorder due to key symptoms such as tremor, rigidity, and bradykinesia. However, it is now being viewed as a complex disorder based on its multifocal neurologic involvement including cognitive decline, autonomic dysfunction, psychotic symptoms, and mood disorders. Although medications have been created along with various treatment guidelines, a cure has yet to be found and symptom management remains consistently elusive. A significant inverse relationship

has been consistently identified between smoking and PD development as well as PD symptoms. One study observed that those who smoked had a 60% lower risk of developing PD. While the neural mechanisms are not yet fully understood, it is thought that nicotine specifically may play a role in decreasing the risk of developing PD. Extensive literature and data analysis was performed on journal articles from 2002 to date. Based on the current data, the inverse relationship between smoking and developing Parkinson's disease is likely due to confounding variables such as other chemicals found in cigarettes or underlying personalities of patients that develop

PD which leads them to avoid novelty-seeking behaviors such as smoking. Further research is necessary to determine neuronal mechanisms induced by chemicals in cigarettes that may decrease the risk of PD development such as 2,3,6-trimethyl-1,4 naphthoquinone (TMN), an inhibitor of monoamine oxidase A and B activity, which has already been used in treatment of PD symptoms. However, based on the currently available research, it is likely that the correlation between smoking and PD is an association rather than a directly contributing factor that will be useful in the reduction of PD development.

133 2025 Research Recognition Day