The silent impacts that microplastics can have on the brain.

A new study has revealed five mechanisms by which microplastics may trigger inflammatory responses and cause damage in the human brain. According to the authors, microplastics may even contribute to worsening or accelerating the progression of neurodegenerative diseases such as Alzheimer's and Parkinson's .

 

Currently, more than 57 million people worldwide are living with some form of dementia. This number is expected to increase significantly in the future, and if microplastics are indeed a contributing factor to these conditions, the impact on public health will be enormous.

According to Associate Professor and pharmaceutical scientist Kamal Dua from the University of Technology Sydney (UTS), each adult is estimated to 'consume' about 250g of microplastics per year – equivalent to a full plate.

 

The sources of microplastics entering the body are diverse, including: seafood, salt, processed foods, tea bags, plastic cutting boards, plastic bottles, contaminated soil, synthetic fibers from clothing and carpets, household dust, etc. Common types of plastics include polyethylene, polypropylene, polystyrene , and PET . Although most are eliminated, research shows that microplastics still accumulate in organs , including the brain .

 

The study, published in the journal Molecular and Cellular Biochemistry, was conducted by a team of scientists from UTS and Auburn University (USA) . The research team identified five biological pathways by which microplastics can harm the brain:

1. Activating immune cells
2. Increased oxidative stress
3. Weakening the blood-brain barrier
4. Causes mitochondrial dysfunction.
5. It causes direct damage to nerve cells.

"Microplastics cause the blood-brain barrier to 'leak'," said Associate Professor Dua, head of the research team. " This activates immune cells and inflammatory molecules, further damaging this protective layer."

The body treats microplastics as 'foreigners,' causing brain immune cells to attack them. At the same time, toxins and environmental pollution intensify the oxidative stress response.

Microplastics cause oxidative stress in two ways: by increasing harmful reactive oxygen species (ROS) and by weakening the body's natural antioxidant system.

"Microplastics affect energy production in mitochondria, causing a drop in ATP – the cell's fuel. When energy is lacking, nerve cells weaken and can be damaged," Dua explained. These mechanisms "work together" to accelerate brain damage progression.

The study also addresses how microplastics may exacerbate Alzheimer's disease by increasing the accumulation of beta-amyloid and tau. It also suggests that microplastics may contribute to Parkinson's disease by promoting α-synuclein aggregation and damaging dopaminergic cells.

Although more evidence is needed to confirm a direct link between microplastics and neurodegenerative diseases, the authors recommend reducing microplastic exposure as much as possible . Measures that could include:

1. Limit your use of plastic items, plastic containers, and plastic cutting boards.
2. Limit the use of clothes dryers (as they produce many microplastic fibers).
3. Prioritize natural fibers over synthetic fibers.
4. Reduce your intake of packaged and processed foods.

They hope these results will support the development of environmental policies aimed at reducing plastic production, improving waste management systems, and minimizing future public health risks.