Pesticides and Parkinson's: Study Shows Connection at Low Chemical Doses

A neurological disease could be rooted in everyday pesticide exposure, a new study suggests.

February 3, 2014


Scientists are starting to untangle the Pesticides-Parkinson's disease connection. A new study, published in the journal Neurology, expands our knowledge of the interplay between common chemicals and the neurological disease by identifying how certain pesticides throw off a specific enzyme's role in keeping dopamine cells healthy.


The study found a broad range of chemical fungicides, weedkillers, and bug-killing insecticides cause a cell detoxifying problem linked to Parkinson's disease, even at very low doses people commonly experience.

The study found that 11 of the 50 chemical pesticides tested inhibited an enzyme called aldehyde dehydrogenase (ALDH). ALDH's job is to detoxify aldehydes to protect dopamine cells. "It's important that dopamine doesn't stay outside of its 'holding place,' that it just doesn't float around the cell," explains study author Beate Ritz, MD, PhD, professor of epidemiology at University of California, Los Angeles. "That's what aldehyde dehydrogenase dose—it helps detoxify it."

The chemical exposure increases the risk of Parkinson's overall, but about half of the U.S. population carries a genetic variant of the ALDH2 gene that makes them even more susceptible. In fact, the strength of the risk depends on an individual's genetic makeup, which in the most pesticide-exposed populations could increase the chances of developing the disease by 2- to 6-fold.

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"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," says study author Jeff Bronstein, MD, PhD, professor of molecular toxicology and neurology at UCLA. "These 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."

The best way to protect your family from the growing list of problems associated with chemical pesticides, eat organic, whole foods as much as possible, use less toxic bug control measures in the home, and use these organic lawn care tips.