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There is a direct link between Parkinson's disease and pesticides
Medical expert of the article
Last reviewed: 01.07.2025
Parkinson's disease affects tens of millions of people worldwide, but the exact causes of the disease are still not fully understood.
Parkinson's disease is a neurodegenerative disorder that affects two percent of people over 65 and four to five percent of people over 85.
For several years, neurologists at the University of California, Los Angeles, conducted a study to determine whether there was a link between pesticides and Parkinson's disease.
Today, experts suspect that maneb, paraquat and ziram – chemicals used to remove broadleaf weeds and grass – are linked to an increase in various diseases not only among agricultural workers, but also among people who simply live and work near cultivated fields.
Now, scientists at the University of California have found a link between Parkinson's disease and another pesticide, benomyl. This toxic pesticide was banned in the United States ten years ago, but its deadly effects are still felt.
Benomyl substances initiate a cascade of cellular events that can lead to the development of Parkinson's disease. The pesticide inhibits the production of the enzyme ALDH (aldehyde dehydrogenase), and this leads to the accumulation of the toxin DOPAL in the brain, which is synthesized by the brain and is responsible for a number of cellular events that lead to Parkinson's disease.
Scientists believe that developing new drugs to protect the activity of the ALDH enzyme could ultimately help slow the progression of the disease, even if a person has never been exposed to pesticides.
The results of the study were published in the scientific journal Proceedings of the National Academy of Sciences.
Parkinson's disease causes progressive muscle stiffness, slowness of movement, and tremors in the limbs. These symptoms are caused by the death of nerve cells in the substantia nigra area of the brain that produce the neurotransmitter dopamine. The origin of Parkinson's disease is not fully understood, but possible causes include aging, certain toxins and substances, such as benomyl, and genetic predisposition.
"Environmental factors are likely to play an important role in the development of the disease," said lead author Professor Arthur Fitzmaurice. "Understanding the mechanisms involved, in particular what causes the selective loss of dopaminergic neurons, may provide important clues to explain how the disease develops and why."
Benomyl was widely used in the United States for three decades until toxicological data showed that the pesticide was potentially dangerous and that continued use could cause liver tumors, brain tumors, birth defects, and reproductive changes. Benomyl was banned in 2001.