What Parkinson’s Research Is Teaching Us About Environmental Risk
Unlike Alzheimer’s, where lifestyle advice is broad, Parkinson’s research is pointing to specific environmental exposures—and what we can do about them.
Deborah Kan is an award-winning journalist and founder of Being Patient. In this “Thought of the Week” column each Friday, she highlights one of the key stories shaping the future of brain science.
Dear readers,
When we added Parkinson’s disease to Being Patient’s coverage last fall, I assumed the research would mirror what we report on Alzheimer’s: A pathology mapped sometimes by genetics. A lifestyle conversation broad enough to apply to many chronic diseases. As our team continues to delve deeper into Parkinson’s, I’m noticing the detailed nuances, especially when it comes to lifestyle factors.
With Alzheimer’s, the modifiable-risk conversation is broad. Sleep. Exercise. Hearing loss. Blood pressure. Diet. Social connection. All of it is real and important. We tell you “lifestyle matters” because it genuinely does.
With Parkinson’s, researchers are pointing at specific molecules.
Being Patient published a piece this week by our reporter Antonia Gallagher on the environmental risks researchers are watching. Only about 13 percent of people with Parkinson’s carry a known genetic variant. Which means roughly 87 percent of patients have no identifiable genetic explanation. Researchers are increasingly looking at specific environmental risk factors.
A few months ago, I shared with you my conversation with Dr. Dorsey about his book The Parkinson’s Plan, which makes the case that our environment shapes Parkinson’s risk in ways most of us, and most of medicine, have underestimated. This week’s reporting builds on that conversation. The question now is what we can actually do.
What’s striking is how named the suspects are. Researchers aren’t talking about pesticides in general. They’re talking about five specific compounds: paraquat, rotenone, chlorpyrifos, ziram, and benomyl. They aren’t talking about solvents in general. They’re talking about trichloroethylene (TCE) and its close cousin perchloroethylene (PCE), the chemical still used in many dry cleaners. They aren’t talking about air pollution in general. They’re talking about fine particulate matter, which researchers believe may travel from the nose into the olfactory bulb of the brain. Pollutants are believed to lead to things like damaged mitochondria and dying dopamine neurons, an important hallmark of Parkinson’s.
That specificity is what gives us something to do.
Dr. Jeff Bronstein at UCLA said, “Just do your best.” He explained that risk is additive and there still needs to be more research to substantiate the tangible risk.
Pesticides carry the most substantiated risk factor. Bronstein’s says the highest exposure happens during application, so the easiest move is not to spray at home if you can avoid it. When that isn’t possible, he recommends protective gear, washing produce thoroughly, and buying organic versions of the items on the Environmental Working Group’s Dirty Dozen list when budget allows. That list catalogs the produce shown to carry the most pesticide residue.
The story with dry cleaning is about a single chemical, perchloroethylene, or PCE. It’s still in use at many cleaners, even though the EPA recently finalized a 10-year phaseout. The fastest way to know what your cleaner uses is to ask. “Green” or “wet cleaning” services don’t rely on PCE, and they’re easier to find now than they were even a few years ago.
Air pollution is the hardest of the three to act on, since most of us can’t control what we breathe. The science on specific protective steps is still developing, but a HEPA air purifier may help reduce indoor particulate exposure, and keeping windows closed on bad air-quality days is a low-cost habit worth building. For anyone on well water, testing it for pesticides and industrial chemicals is a starting point, and a charcoal filter can capture some contaminants.
After our reporting, I made two changes. I switched to a green-certified dry cleaner, and I installed a reverse osmosis water filter at home. We’re not on well water, and I won’t pretend either change is going to single-handedly protect my brain. But I keep coming back to Bronstein’s framing. Risk is additive. If risk adds up, so does protection, and every layer counts.
With hope,
Deborah
