Increasing Microplastics Have Infiltrated Our Brains

Microplastics in house dust. Credit : Utrecht University

With widespread use of plastics that do not break down in the environment, microplastics are quickly becoming a major health concern. These tiny pieces of plastic—less than five millimeters in size—are unavoidable as we eat and drink from plastic bottles and wrappers. Now, there is evidence that microplastics have made it past the protective membrane that is supposed to keep toxins and viruses away from the brain.

A group of researchers at the University of New Mexico Health Services have published a study on February 3, 2025 that shows significant increases in concentrations of microplastics in the brain and that the brain might be more susceptible to microplastic bioaccumulation than other organs (Nihart, A.J., et al., 2025). Comparing 28 brain specimens from 2016 to 24 brain specimens from 2024, there was a 50% higher concentration of microplastics, unsurprisingly corresponding to the rate of plastic production that doubles every 10-15 years. Microplastics concentrations are increasing because there is no natural way for them to pass through the body, so they bioaccumulate and stay in your organ tissue.

Although research is still new and ongoing, there is evidence that suggests microplastics in the brain can affect cognitive function. Brain tissue from people with dementia had concentrations of microplastics that were three to five times higher than other samples. Whether the microplastics cause or exacerbated the dementia is unclear because of how the blood-brain protective membrane is thinner in brains diagnosed with dementia. The greater science community has also identified ways that microplastics can lead to inflammation in organs that can inhibit function and commended this new study for its findings that underscore the danger that microplastics pose (Washington Post).

But if microplastics are ubiquitous, then how can we reduce exposure in a world where completely avoiding microplastics is impossible? On the global scale, governments and corporations must help contribute to reducing plastic production. However, there are many steps we can take in our daily lives that span eating habits to what kinds of clothes we buy. For food, we can avoid food packaged in single-use plastic, microwaving food in plastic containers, and eating lower on the food chain since microplastics biomagnify (UCSF). For clothes, we can buy clothes made of natural fibers and wash current synthetic fabrics less so they flake off less. For everyday tasks, switch to wood cutting boards or vacuum more to remove microplastics from the air (WUST). These individual choices are important for exposure on the personal level and for reducing waste in general.