Common pesticide linked to 2.5 times the risk of Parkinson’s disease
A UCLA study found that long-term exposure to a common pesticide was linked to more than 2.5 times the risk of Parkinson's disease. Scientists also uncovered how the chemical damages brain cells and identified a promising way to protect them.
Key points
- Long-term residential exposure to chlorpyrifos was linked to over 2.5 times the Parkinson's risk in a UCLA study.
- Mice exposed to chlorpyrifos aerosol for 11 weeks developed movement problems and lost dopamine-producing neurons.
- Chlorpyrifos disrupted autophagy, the brain's cellular cleanup process, causing damaged proteins to accumulate.
A pesticide used in agriculture for decades may be linked to a much higher risk of Parkinson's disease, and UCLA Health researchers say they have found a possible biological explanation. The study, published in Molecular Neurodegeneration, found that people with long-term residential exposure to chlorpyrifos had more than 2.5 times the risk of developing Parkinson's compared with those not exposed.
The research combined human population data with laboratory experiments. It examined 829 people with Parkinson's and 824 without the condition, all enrolled in UCLA's Parkinson's Environment and Genes study, and used California pesticide application records with participants' address histories to estimate exposure.
Animal and cell experiments
Mice exposed to chlorpyrifos in aerosol form for 11 weeks developed movement difficulties and lost neurons that produce dopamine, a central feature of Parkinson's. The animals also showed brain inflammation and abnormal clumps of alpha-synuclein protein.
Experiments in zebrafish indicated that chlorpyrifos interferes with autophagy, a cellular process that removes damaged proteins. When researchers restored this cleanup process or removed synuclein protein, neurons were protected from damage.
This study establishes chlorpyrifos as a specific environmental risk factor for Parkinson's disease, not just pesticides as a general class
— Dr. Jeff Bronstein
What the lead author said
Dr. Jeff Bronstein, professor of Neurology at UCLA Health and the study's senior author, said the work identifies a specific chemical risk rather than treating all pesticides as one category. He also said the animal models suggest the association is likely causal and that the autophagy finding points toward potential therapeutic strategies.
