A new study coming out of the University of Guelph appears to have discovered why exposure to pesticides increases a person’s risk of developing Parkinson’s disease.
While many studies in the past have demonstrated a link between Paraquat and Maneb (two commonly used agrochemicals) and Parkinson’s, this new study actually investigates the process and form that link takes within the cells themselves.
Professor Scott Ryan, lead researcher of the study, has determined that low-level of exposure to pesticides disrupts cells in such a way that mimics the mutations that cause Parkinson’s.
When the effects of the chemicals are taken in concert with a genetic predisposition to Parkinson’s, the risk of Parkinson’s onset is drastically increased.
“People exposed to these chemicals are at about a 250-per-cent higher risk of developing Parkinson’s disease than the rest of the population,” said Ryan, a professor in the Department of Molecular and Cellular Biology.
“We wanted to investigate what is happening in this susceptible population that results in some people developing the disease.”
Paraquat and Maneb are used on a variety of Canadian crops with the former being used on crops during the growth period and the latter used in order to prevent spoiling after harvest.
The study, which was published in the Federation of American Societies for Experimental Biology, used stem cells from people with Parkinson’s disease using a mutation in a gene called synuclein which is associated with an increased risk of the disease. The study also used normal embryonic stem cells in which the mutation was introduced via gene editing.
“Until now, the link between pesticides and Parkinson’s disease was based primarily on animal studies as well as epidemiological research that demonstrated an increased risk among farmers and others exposed to agricultural chemicals,” said Ryan. “We are one of the first to investigate what is happening inside human cells.”
Ryan’s research team made dopamine-producing neurons — the neurons affected by Parkinson’s — from both types of the stem cells and then exposed them to the chemicals.
The exposure of the neurons to the chemicals prevented energy-producing mitochondria from moving where they need to go inside the cells which in turn depleted the neurons of energy.
According to the University of Guelph press release, “Neurons from the Parkinson’s patients and those in which the genetic risk factor was introduced were impaired at doses below the U.S. Environmental Protection Agency’s reported lowest observed effect level. Higher doses are needed to impair function in normal neurons.”
“People with a predisposition for Parkinson’s disease are more affected by these low level exposures to agrochemicals and therefore more likely to develop the disease,” said Ryan. “This is one of the reasons why some people living near agricultural areas are at a higher risk.”
Ryan stated that the findings indicate that the current acceptable levels of these two agrochemicals should be reassessed.
“This study shows that everyone is not equal, and these safety standards need to be updated in order to protect those who are more susceptible and may not even know it.”
This article was originally published by Natural Blaze