A new study from neurologists at UCLA adds to the growing scientific evidence showing an ever stronger link between exposure to pesticides and development of Parkinson’s disease.
This latest study documents how the fungicide benomyl triggers a cascade of events at the cellular level that increase the likelihood of developing Parkinson’s. The researchers say the findings clarify the role of naturally occurring enzymes in the brain, and may help in efforts to slow progression of the disease — even among those not exposed to pesticides. The study also confirms that avoiding pesticide exposure can only help.
This is the latest in a series of pesticide culprits such as paraquat, maneb and ziram that have been linked to Parkinson’s in people living and working in areas where these pesticides are used.
The exposures can do their damage years before the symptoms actually occur. Benomyl has been banned for years in the U.S., but the effects are still showing up. This long-term nature of the impacts also showed up in an earlier study by the neuroscientists at UCLA's School of Public Health.
Study suggests potential new target in fight against debilitating disease
For several years, neurologists at UCLA have been building a case that a link exists between pesticides and Parkinson's disease. To date, paraquat, maneb and ziram — common chemicals sprayed in California's Central Valley and elsewhere — have been tied to increases in the disease, not only among farmworkers but in individuals who simply lived or worked near fields and likely inhaled drifting particles.
Now, UCLA researchers have discovered a link between Parkinson's and another pesticide, benomyl, whose toxicological effects still linger some 10 years after the chemical was banned by the U.S. Environmental Protection Agency.
Even more significantly, the research suggests that the damaging series of events set in motion by benomyl may also occur in people with Parkinson's disease who were never exposed to the pesticide, according to Jeff Bronstein, senior author of the study and a professor of neurology at UCLA, and his colleagues.
Benomyl exposure, they say, starts a cascade of cellular events that may lead to Parkinson's. The pesticide prevents an enzyme called ALDH (aldehyde dehydrogenase) from keeping a lid on DOPAL, a toxin that naturally occurs in the brain. When left unchecked by ALDH, DOPAL accumulates, damages neurons and increases an individual's risk of developing Parkinson's.
The investigators believe their findings concerning benomyl may be generalized to all Parkinson's patients. Developing new drugs to protect ALDH activity, they say, may eventually help slow the progression of the disease, whether or not an individual has been exposed to pesticides.