Microplastics may be fuelling the rise of neurodegenerative diseases like Alzheimer’s and Parkinson’s, according to a new research review. The study highlights five biological pathways through which these particles can trigger inflammation and cellular damage in the brain.
More than 57 million people worldwide live with dementia, and cases of these conditions are expected to increase sharply. Therefore, the possibility that microplastics could accelerate brain diseases raises serious global health concerns.
The systematic review, recently published in Molecular and Cellular Biochemistry, was an international collaboration led by researchers from the University of Technology Sydney and Auburn University in the US.
How Much Microplastic Do We Consume?
Researchers estimate that adults ingest almost 250 grams of microplastics every year, which is roughly enough to cover an entire dinner plate. These particles enter the body through contaminated seafood, salt, processed foods, plastic tea bags, and plastic-packaged drinks.
We also inhale microplastics from carpets, synthetic clothing, household dust, and polluted air. Although the body eliminates most particles, some accumulate in organs, including the brain.
Five Ways Microplastics May Damage the Brain
1. Triggering Immune Cell Activation
Microplastics act as foreign invaders, prompting immune cells in the brain to attack them. This reaction increases inflammation and weakens long-term brain health.
2. Generating Oxidative Stress
These particles boost reactive oxygen species, which are unstable molecules that damage cells. They also reduce the body’s antioxidant defences, creating an imbalance that stresses brain tissue.
3. Disrupting the Blood–Brain Barrier
Microplastics weaken the protective barrier surrounding the brain, making it leaky. This allows inflammatory molecules to enter and causes additional damage.
4. Impairing Mitochondrial Function
Mitochondria create ATP, which fuels brain cells. Microplastics reduce ATP production, weakening neurons and disrupting normal cellular activity.
5. Damaging Neurons Directly
All these pathways interact and increase the risk of neuron damage. This potentially accelerates cognitive decline associated with neurodegenerative diseases.
Links to Alzheimer’s and Parkinson’s Disease
The study also explains how microplastics may contribute to key processes involved in Alzheimer’s and Parkinson’s.
- In Alzheimer’s, they may increase the buildup of beta-amyloid and tau proteins.
- In Parkinson’s, they may enhance α-synuclein aggregation and damage dopaminergic neurons.
Although these findings are concerning, researchers emphasise that more evidence is required to establish a direct cause-and-effect relationship.
What Are Researchers Doing Now?
Scientists are investigating how microplastics move through the body, where they accumulate, and how they disrupt brain cell function. Ongoing projects include studies on inhaled microplastics and their impact on lung and brain health.
The researchers hope their findings will guide environmental policies aimed at reducing plastic pollution and improving long-term public health.
How to Reduce Your Microplastic Exposure
Experts recommend simple lifestyle changes to reduce personal microplastic intake:
- Avoid plastic containers and plastic chopping boards.
- Choose natural fibre clothing instead of synthetic materials.
- Skip the clothes dryer when possible to limit air-borne plastic fibres.
- Reduce consumption of processed and plastic-packaged foods.
- Use reusable bottles, cloth bags, and eco-friendly kitchen products.
These small changes can significantly lower microplastic exposure over time.
Q&A
Q: Can microplastics really enter the brain?
Yes. Studies show that some microplastics can cross the blood–brain barrier, especially when that barrier becomes weakened.
Q: Are microplastics proven to cause Alzheimer’s or Parkinson’s?
Not yet. However, emerging evidence shows they may contribute to processes that worsen these conditions.
Q: How common is microplastic ingestion?
Extremely common. People consume microplastics daily through food, water, air, and household dust.
Q: Can reducing plastic use help protect brain health?
It may. Lower exposure reduces the number of particles entering the body, which could lessen long-term risks.
FAQs
What are microplastics?
Microplastics are tiny plastic particles under five millimetres in size that come from degraded plastics or manufactured products.
Where are microplastics found?
They are found in oceans, soil, bottled water, processed foods, household dust, and even the air we breathe.
Why are microplastics harmful?
They can trigger inflammation, oxidative stress, and cell damage, especially when they accumulate in organs.
Do microplastics affect children and older adults differently?
Yes. Vulnerable groups may experience stronger impacts due to weaker immune systems or ongoing neurological changes.
Can environmental policies reduce microplastic risks?
Improved waste management, reduced plastic production, and strict pollution controls can significantly lower future exposure.
