Microplastics detected in human brain tissue: Could they be linked to dementia?

Dubai: Microplastics, tiny plastic particles less than 5 millimetres in size, have already been discovered in human breast milk, Antarctic sea ice, the Mariana Trench (the world’s deepest ocean trench), and drinking water. Now, these ever-present particles have made their way into the human brain, according to new research published in Nature Medicine in February.

Researchers from the University of New Mexico Health Sciences found that the human brain may contain up to a disposable spoon’s worth of these tiny plastic shards. What alarmed scientists and the media alike was the study’s finding that individuals with dementia had significantly more microplastics in their brains than those without the condition.

Alarming levels in brain tissue

The study examined brain, liver, and kidney tissue samples from 28 people who died in 2016 and 24 who died in 2024, all in New Mexico. Among all organs studied, microplastic concentrations were highest in brain tissue and were particularly elevated in the 2024 samples compared to those from 2016.

Professor Matthew Campen, a pharmaceutical sciences expert at the University of New Mexico, told The New York Times that the plastics detected were far smaller than previously recorded. This may help explain how they bypass the body’s natural defences to infiltrate critical organs.

Should we be worried?

While the findings suggest a potential link between microplastics and cognitive decline, scientists, including Dr Campen have emphasised that the research is still in its early stages. The study does not definitively conclude that microplastics cause dementia.

Dr Qamar Bashir Mirza, a specialist in neurology at Aster Cedars Hospital and Clinic in Jebel Ali, echoed this caution in a statement to Gulf News, noting that the discovery of microplastics in brain tissue is a “complex issue” and that the “jury is still out.” Ongoing research aims to better understand the neurological implications.

Although the cause-and-effect relationship is not yet clear, that does not mean we should be complacent and continue our lives without making changes to reduce our exposure to microplastics, particularly as polyethene, the most commonly found plastic in the study, accounted for 75 per cent of the total. Widely used in plastic bags and food and drink packaging (which the UAE is currently phasing out), these particles were mostly detected in the brain as ‘nanoplastic’ shards.

Microplastics and the brain: A potential link to cognitive issues

“It seems microplastics in the brain disrupt cellular processes. Hypothetically, their presence could affect the integrity of neural networks, but conclusive evidence is awaited,” said Dr Mirza. He added that the size, shape, and chemical composition of microplastics likely play a role in determining their biological effects.

Microplastics have previously been detected throughout the human body including in the blood, saliva, liver, kidneys, lungs, and placenta. These particles can cause inflammation and disrupt hormones, and it is plausible they trigger similar responses in brain tissue.

“Inflammation is a key factor in many neurodegenerative diseases, including Alzheimer’s and Parkinson’s. However, it is premature to conclude that microplastics directly increase the risk of such conditions. It seems from the latest findings that plastics can breach the blood-brain barrier, persist in neural tissue, and interact with brain cells,” he explained.

Although further research is needed to establish a link between microplastics and cognitive decline, Dr Mirza emphasised that one key takeaway from these findings is the urgent need for continued vigilance and the importance of reducing microplastic exposure through mindful lifestyle choices.

How microplastics enter our bodies and homes

Given that microplastics are virtually everywhere, avoiding them entirely is nearly impossible. To reduce exposure, it's important to understand how they enter our environments and, ultimately, our plates, homes, and bodies.

“Microplastics are tiny plastic fragments, often invisible to the naked eye, and less than 5 millimetres in diameter. They are created when everyday items like tyres and plastic bags, break down,” said Dima Maroun, a UAE-based environmental scientist and Chief Sustainability Officer, as well as co-founder of Thriving Solutions, with over 20 years of experience in the environmental and sustainability field, in an interview with Gulf News.

Microplastics infiltrate homes and bodies through a variety of common household and personal products. “Primary microplastics are intentionally manufactured to be small, such as microbeads in personal care products and pre-production plastic pellets known as nurdles,” Maroun said.

Secondary microplastics, on the other hand, come from the breakdown of larger plastic items. “This includes bottles, toys, bags, and packaging. Exposure to elements like wind, sunlight, and water causes these items to break down, eventually turning into microplastics,” she added.

Another significant route of microplastic exposure is through bioaccumulation in ecosystems. Maroun compared this to how pesticides accumulate in animal fat tissue over time. When smaller animals ingest toxins and are then eaten by predators, the concentration of these toxins increases as they move up the food chain.

“This same process applies to microplastics in marine ecosystems, posing a health risk not only to sea life but also to humans who consume seafood as part of their diet,” she noted.

Is it possible to avoid microplastics in my daily life?

Rather than asking how to avoid microplastics altogether, a more practical question is how to reduce your exposure at home and in your everyday routine. With microplastics now found in nearly every part of the human body and in even the most remote corners of the planet small, conscious changes can help reduce interaction. 

Here are a few pointers on how you can create an ‘anti-microplastic’ environment in your home, according to Maroun:

• Choose natural cleaning materials like cotton cloths or cellulose sponges instead of synthetic microfibre ones.

• Support brands that use sustainable materials in their products.

• Air-dry clothes rather than using a tumble dryer, to minimise synthetic fibre shedding.

• Install a washing machine filter to capture microplastics before they reach the water system.

• Use air purifiers with HEPA filters in rooms with synthetic textiles.

• Clean with a vacuum equipped with a HEPA filter.

• Reduce the use of plastic packaging when shopping for food.

• Avoid microwaving food in plastic containers.

• Wash fresh produce thoroughly to remove surface microplastics.

Maroun emphasised that meaningful, long-term impact requires collective action. This includes investment in improved waste management infrastructure to ensure proper collection, recycling, and disposal of plastic waste, preventing it from leaking into the natural environment.

Equally important is the enforcement of policies banning single-use plastics, a step already taken in Dubai and across the UAE. Holding corporations accountable and encouraging businesses to adopt sustainable practices throughout their supply chains is also critical.

Public awareness campaigns can play a key role by educating people on the risks and health impacts of microplastics, driving behavioural change across communities.

“Investment in scientific research is vital to understand the long-term environmental and health consequences of microplastics,” Maroun concluded. “Science-based policy and technological innovation will be key to tackling this growing issue.”