A newly published study further investigates the link between pesticides and Parkinson’s disease. Previous studies have already shown that exposure to certain pesticides can increase the risk of Parkinson’s by interfering with the body’s ability to break down a toxic substance. This latest study, published in the Feb. 5, 2014 issue of Neurology, further investigates this risk and identifies a genetic component that makes some individuals more vulnerable to the disease when exposed to certain pesticides.
In January 2013, a UCLA research team published a study showing that the fungicide benomyl increases the risk of Parkinson’s by inhibiting aldehyde dehydrogenase (ALDH). ALDH is an enzyme that converts aldehyde, which is highly toxic to dopamine cells, into a less toxic chemical. Parkinson’s disease is heavily associated with a loss of dopamine-producing cells in the brain. The findings were published in the Proceedings of the National Academy of Sciences.
Now, that same UCLA group has identified 11 other pesticides that inhibit ALDH. What’s concerning is that this link is found at much lower levels than what is actually used. “We were very surprised that so many pesticides inhibited ALDH and at quite low concentrations, concentrations that were way below what was needed for the pesticides to do their job,” said Jeff Bronstein, lead author and professor of neurology and director of movement disorders at UCLA. He says that the pesticides “are pretty ubiquitous, and can be found on our food supply and are used in parks and golf courses and in pest control inside buildings and homes. So this significantly broadens the number of people at risk.”
Bronstein and his team used information from the California Department of Pesticide Regulation to conduct the study. The authors looked at 360 patients with Parkinson’s and 816 without Parkinson’s, all living in three agricultural heavy counties in Central California. The study focused specifically on people who had ambient exposure to pesticides in work and at home.
The authors found that genetics play a factor in the link between Parkinson’s and pesticide exposure. People who have a genetic variation of the ALDH2 gene are especially sensitive to the risk of ALDH-inhibiting pesticides, and are two to six times as likely to develop Parkinson’s compared to people who do not have this variant. Notably, having this variant alone does not increase the risk of Parkinson’s.