New Connection Links Parkinson's Disease with Pesticide Exposure
Scientific evidence already has connected pesticide exposure with an increased risk of Parkinson's disease. Chemicals like paraquat, maneb, and ziram, commonly found in pesticides have been found in farmworkers and others living and working near the fields, and are tied to an increase in the disease. New research has identified another chemical from pesticides, benomyl, that is linked to Parkinson's. The toxic effects of benomyl are still found in the environment, even 10 years after the chemical was banned by the EPA. This chemical triggers a series of cellular events leading to Parkinson's.
Parkinson's is a degenerative disorder of the central nervous system. The most obvious symptoms are involuntary shaking, rigidity, slower movement, and difficulty walking or walking with a gait. As it advances, it can lead to dementia, sensory, sleep, and emotional problems. Famous individuals who suffer from the disease include actor Michael J. Fox and boxer Muhammad Ali.
Benomyl exposure begins the process of Parkinson's by blocking the enzyme called ALDH, which is an enzyme responsible for preventing a toxin called DOPAL from accumulating in the brain. If the enzyme is blocked, DOPAL in the brain will eventually damage neurons and increase the risk of the disease.
For three decades, benomyl was used widely in pesticides in the USA. Evidence began to arise identifying its toxic effects including tumors, brain malfunction, carcinogenesis, and reproductive disorders. Benomyl was banned in 2001.
The new research conducted at the University of California, Los Angeles (UCLA) made the connection between benomyl and Parkinson’s. Most importantly, they identified the target enzyme, ALDH. This enzyme can be the focus of future research. If there is a way to prevent ALDH from being blocked by bodily contaminants, then the DOPAL could never build up and damage the nervous system.
"We've known that in animal models and cell cultures, agricultural pesticides trigger a neurodegenerative process that leads to Parkinson's," said Bronstein, who directs the UCLA Movement Disorders Program. "And epidemiologic studies have consistently shown the disease occurs at high rates among farmers and in rural populations. Our work reinforces the hypothesis that pesticides may be partially responsible, and the discovery of this new pathway may be a new avenue for developing therapeutic drugs."
The study has been published in the Proceedings of the National Academy of Sciences
Pesticide Spraying image via Shutterstock