Microplastics and Dementia: Is There a Hidden Connection?

By Ram Rao, Ph.D., Principal Research Scientist for Apollo Health

Microplastics come from the breakdown of plastic waste, synthetic fibers, and personal care products. Scientists have detected them in human lungs, blood, placentas, and even brain tissue. While definitive causal evidence in humans between microplastics and dementia is still lacking, animal studies provide disturbing clues. Mice exposed to microplastics showed structural and functional changes in brain tissue, leading to memory issues and cognitive decline. These findings mirror the hallmarks of dementia, including neuronal death and chronic inflammation. A 2024 study from the University of Vienna demonstrated that micro- and nanoplastics (MNPs) cross the blood-brain barrier and trigger neuroinflammation, an underlying factor in neurodegenerative diseases like Alzheimer’s.

Preliminary studies in humans show that individuals diagnosed with dementia had MNP levels 3-5 times higher than those of normal individuals. What is even more concerning is that the brain tissue contained MNP concentrations 7 to 30 times higher than those found in other organs, such as the liver or kidney. Particularly worrisome are particles smaller than 200 nanometers, termed nanoplastics, which are primarily composed of polyethylene and have been found to accumulate in cerebrovascular walls and immune cells. Due to their minuscule size, these particles may be capable of crossing the blood-brain barrier, raising concerns about their potential contribution to neurological diseases.  What is still unclear is whether MNPs caused the damage or were simply present as a result of an exponential rise in environmental microplastic pollution and a compromised blood-brain barrier.

Clearly, more research, particularly in humans, is necessary to reach definitive conclusions about the potential link between MNPs and brain health. If future research establishes a causal relationship, it could lead to new strategies for preventing dementia, addressing not only genetics, diet, and lifestyle but also environmental exposures. In the meantime, we can take preventative steps to limit microplastic exposure, including the following:

1. Minimize Single-Use Plastics:
   • Avoid plastic water bottles: Switch to reusable water bottles made of stainless steel or glass. 
   • Reduce plastic food packaging: Choose fresh or minimally processed foods, or those packaged in paper, glass, or metal. 
   • Avoid plastic takeout containers: Use reusable containers for food. 
   • Swap plastic for non-plastic alternatives: Use heat-safe glass, stainless steel, or ceramic utensils/containers for food storage, cooking, heating, or eating.
   • Avoid plastic bags: Use reusable cloth bags. 
   • Limit plastic tea bags: Use loose-leaf tea
    
2.  Filter Water:
   • Use a water filter: Invest in a filter certified to remove microplastics and other contaminants.
    
3. Choose Natural Fibers:
   • Use of natural fabrics: Wear clothing made from natural fibers like cotton, hemp, jute, or linen, which shed fewer microplastic fibers during washing. 
   • Reduce synthetic fiber exposure: Choose furniture and rugs made from natural materials.
    
4. Maintain a Clean Home:
   • Regularly vacuum and dust: Microplastics can settle in dust and air, so regular cleaning helps remove them. 
   • Use HEPA filters: HEPA filters can capture airborne microplastics. 
    
5. Be Mindful of Food and Drink:
   • Avoid heating food in plastic: Heating plastic can release microplastics into food. 
   • Avoid canned goods: Canned foods are lined with BPA-containing plastic that can leach into the food.
    
6. Change Laundry Habits:
   • Use a microfiber filter on your washing machine: This can trap microplastics released during washing.
    
7. Personal Care Products:
   • Use plastic-free cosmetics: Choose cosmetics and beauty products without plastic microbeads. 

Researchers also urge exploring ways to eliminate MNPs from the body since our body can naturally excrete MNPs through sweat, urine, and feces. The liver’s detox processes can also play a role. 

Excretion:

Studies have shown that some plastic-derived compounds, like BPA, can be detected in sweat, suggesting that sweating is one method to clear these micro compounds.

Urinary Excretion:

MNPs can be filtered by the kidneys and excreted in the urine, although research is still ongoing to fully understand the mechanisms involved. 

Fecal Excretion:

Dietary fiber helps eliminate microplastics from the body by trapping them and preventing their absorption into the bloodstream, thereby facilitating their removal through the stool.

Liver Detoxification:

The liver plays a crucial role in detoxifying the body, and this can help process and eliminate some MNPs. 

A lot remains unknown, and researchers are calling for urgent research to establish safe exposure thresholds and to investigate the long-term health consequences of microplastic accumulation. They stress the need for large-scale human studies to determine dose-response relationships between microplastic exposure and chronic brain conditions, including dementia. As our understanding deepens, minimizing plastic exposure may not only be beneficial for the planet, but also for our brains.

Meal Delivery Services
As most of you are aware, Apollo Health has partnered with Trifecta, a nationwide leader amongst science-based meal delivery services, to offer KetoFLEX 12/3 meals. Trifecta uses recyclable white plastic BPA/BPS-free containers, safer than black plastic containers, which have been found to contain flame retardants and other heavy metals. To further reduce exposure to microplastics and other chemicals, the team at Trifecta completely cools the food before it is transferred into the containers. As an additional safety precaution, we recommend that customers transfer their meals to a heat-safe glass or ceramic plate if microwaving. In an ideal scenario, all meal delivery services would use trays made from fully compostable rigid cardboard, but even many of those have been found to contain PFAS chemicals and other toxins and have difficulty maintaining integrity for meal delivery.