Want To Protect Your Brain Health? This Chemical Exposure Is One You Can Act On
Parkinson’s disease is often talked about as an inevitable part of aging or a roll of the genetic dice. But that explanation has always felt incomplete. Why do rates keep rising? And why do so many people with Parkinson’s have no clear family history at all?
Over the past decade, researchers have been quietly uncovering another piece of the puzzle: the environments we live in, and the chemicals we’re exposed to over time, may matter far more than we once thought.
A new study1 from UCLA Health sheds light on this concern. The research links long-term exposure to a common agricultural pesticide, chlorpyrifos, to more than a 2.5-fold increase in Parkinson’s disease risk. What makes this study stand out isn’t just the strength of the association; it’s that the researchers were also able to show how this chemical damages the brain, down to the cellular level.
Taken together, the findings suggest Parkinson’s isn’t just something that happens to us. In some cases, it may be shaped, slowly and silently, by environmental exposures that began years or even decades earlier.
How researchers connected pesticide exposure to Parkinson’s
The study, published in Molecular Neurodegeneration2, drew on data from UCLA’s Parkinson’s Environment and Genes study, one of the most detailed long-term investigations into environmental risk factors for the disease.
Researchers compared ~830 people with Parkinson’s disease to ~830 people without it, looking closely at where participants lived and worked over time. Using California’s detailed pesticide use reports, the team estimated long-term exposure to chlorpyrifos based on proximity to agricultural applications.
This mattered because chlorpyrifos was widely used for decades. Although residential use was banned in 2001 and agricultural use was restricted in 2021, millions of people were exposed for years before those changes took effect.
To test whether that exposure could realistically damage the brain, the researchers moved into the lab. They exposed mice to chlorpyrifos using inhalation methods designed to mirror how humans encounter the chemical. Zebrafish experiments were then used to dig into what was happening at a cellular level.
A look inside the brain
The population-level results were clear. People with long-term residential exposure to chlorpyrifos had more than 2.5 times the risk of developing Parkinson’s disease compared to those without exposure.
The animal studies helped explain why.
Mice exposed to the pesticide developed movement impairments and lost dopamine-producing neurons, the same neurons that progressively die in Parkinson’s disease. Their brains also showed increased inflammation and abnormal buildup of alpha-synuclein, a protein that forms toxic clumps in Parkinson’s patients.
The zebrafish experiments revealed the underlying mechanism. Chlorpyrifos disrupted autophagy, the brain’s internal cleanup system responsible for clearing damaged proteins and cellular waste. When autophagy slowed down, harmful proteins accumulated, and neurons became more vulnerable. When researchers restored this cleanup process or removed synuclein, the neurons were largely protected.
In short, the pesticide didn’t just correlate with disease. It interfered with one of the brain’s most essential protective systems.
What this means for protecting brain health
This study doesn’t suggest that exposure guarantees Parkinson’s. But it does reinforce several important takeaways:
- Environmental exposures can shape brain health over time, often long before symptoms appear
- Parkinson’s risk isn’t purely genetic and may be partially preventable
- Protecting cellular cleanup processes like autophagy could be a promising avenue for future therapies
On a practical level, it also highlights the importance of minimizing unnecessary chemical exposures where possible and taking environmental risk factors seriously as part of long-term neurological health.
5 simple ways to reduce pesticide exposure
You can’t avoid every environmental chemical, but you can lower your overall exposure in meaningful ways.
Be strategic with produce
When possible, choose organic versions of produce known to carry higher pesticide residues. Washing and scrubbing fruits and vegetables thoroughly can also help reduce surface chemicals.
Clean your indoor air
Pesticides can accumulate in household dust. Using a HEPA air purifier, vacuuming with a HEPA filter, and dusting surfaces can lower inhalation exposure over time.
Check home and garden products
Chlorpyrifos is banned for residential use in the U.S., but other neurotoxic pesticides are still present in lawn, garden, and pest-control products. Look for integrated pest management (IPM) approaches or non-chemical alternatives whenever possible.
Support your brain health
Healthy sleep, regular movement, and a fiber-rich, plant-forward diet help support the brain’s natural cellular cleanup systems and overall resilience.
The takeaway
Parkinson’s disease may feel unpredictable, but research like this suggests it isn’t entirely random. Long-term exposure to certain pesticides, including chlorpyrifos, appears to increase risk by damaging dopamine-producing neurons and disrupting the brain’s ability to clean up cellular waste.
And while these findings can feel disheartening, they also offer something important: clarity. By identifying specific environmental risk factors and the biological pathways they affect, this research opens the door to earlier monitoring, smarter prevention strategies, and future therapies designed to protect vulnerable brain cells. Understanding risk doesn’t eliminate uncertainty, but it does give us leverage.
