Individuals who have used either one of two pesticides — rotenone and paraquat — have developed Parkinson’s disease about 2.5 times more often than non-users.
This finding is according to research organized by the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health and the Parkinson’s Institute and Clinical Center in Sunnyvale, California.
“Rotenone directly inhibits the function of the mitochondria, the structure responsible for making energy in the cell,” said Freya Kamel, Ph.D., a researcher in the intramural program at NIEHS and co-author of the paper.
“Paraquat increases production of certain oxygen derivatives that may harm cellular structures. People who used these pesticides or others with a similar mechanism of action were more likely to develop Parkinson’s disease.”
For the study, 110 individuals with Parkinson’s disease and 358 matched controls were examined to determine the relationship between Parkinson’s disease and exposure to pesticides or other substances harmful to nerve tissue.
All participants were part of the Farming and Movement Evaluation (FAME) Study, part of the larger Agricultural Health Study, a farming and health study of approximately 90,000 licensed pesticide applicators and their spouses.
Parkinson’s diagnoses were backed by movement disorder specialists, and the researchers affirmed the lifelong use of pesticides through detailed interviews.
Neither paraquat nor rotenone is registered for residential or home garden use. Paraquat use has long been restricted to certified users only, mostly due to negative study results associating animal models with Parkinson’s disease. Rotenone as a pesticide is only allowable against invasive fish species.
“These findings help us to understand the biologic changes underlying Parkinson’s disease. This may have important implications for the treatment and ultimately the prevention of Parkinson’s disease,” said Caroline Tanner, M.D., Ph.D., lead author of the study and clinical research director of the Parkinson’s Institute and Clinical Center.
The study is published online in the journal Environmental Health Perspectives.
Source: National Institutes of Health