Microplastics and brain diseases: what new research tells us

By Sarah Currie-Halpern

The last two years have seen an impressive leap forward in research concerning microplastics and nanoplastics, and what these tiny synthetic particles do to our bodies. Truth be told, it’s not looking great.

First published in 2024, a New England Journal of Medicine study found microplastics and nanoplastics (MNPs) in carotid artery plaques, the fatty deposits that build up over time and lead to strokes. Additional studies have suggested a further link between MNPs and strokes, based on how MNPs aggravate vascular inflammation and damage the blood-brain barrier. These adverse effects could also contribute to the progression of neurodegenerative diseases like Alzheimer’s and Parkinson’s. Researchers at the University of New Mexico recently found that the postmortem brain tissue of dementia patients had ten times more MNPs than those without dementia.

We don’t have conclusive proof that microplastics cause neurodegenerative diseases in people who wouldn’t otherwise have them. Medical research at this level takes time, and every study stops well short of declaring causation. In the case of the UNM study, for instance, it’s still possible that diseased brains simply accumulate more plastic particles than non-diseased ones. That being said, most studies treat microplastics as a neurotoxic risk factor and recommend reducing unnecessary exposure.

That exposure takes many forms, as does its prevention. We eat, breathe, and absorb MNPs from a wide variety of sources. Eliminating all MNPs in our lives is functionally impossible, but limiting our exposure is not.

Start in your kitchen. Use a reverse osmosis filter for drinking water and store food in glass or stainless steel. Never microwave anything in a plastic container, only glass or ceramic. Hot liquids should never go in plastic containers unless specifically designed for heat, and try to avoid plastic utensils and cutting boards whenever possible. Quit bottled water, as it often has substantially more MNPs than tap water. Since multiple steps of food processing, packaging, and industrial handling introduce MNPs, try to limit how much processed food you eat.

Glass food jars

Food and drink aside, prevention extends to reducing indoor dust with a HEPA-filter vacuum. Ventilate regularly. Clothes made from synthetic fibers like polyester, nylon, and acrylic are among the biggest sources of microplastics in our homes. Buy garments made from natural fibers like cotton, wool, and hemp whenever possible.

More difficult than MNP prevention is detoxification. There are no scientifically proven methods for an effective MNP detox. We haven’t even determined how long different types of particles stay in different kinds of tissues, meaning a hypothetical detox is unlikely to be a one-size-fits-all process.

Don’t despair. The body has a built-in MNP purging system, meaning the vast majority of ingested particles pass normally through and out of our digestive system. This isn’t new research: One 2019 study found ten common types of microplastics in stool samples, and current evidence suggests that absorption through the intestinal barrier is primarily limited to the smallest particles.

Healthy foods including fruits, vegetables, nuts and legumes

For now, eating right might be the closest thing we have to a detoxification hack. You can’t eat a microplastic-eliminating meal, but research published last year found that antioxidants in fruits, vegetables, and nuts could counteract hormonal imbalances, reductions in fertility, damage to reproductive organs, and other harmful effects caused by MNPs. These antioxidants may counteract MNP-related damage well enough to be incorporated into future therapies.

The best available evidence supports prevention as the best and simplest strategy. Reduce exposure and let our bodies’ normal clearance mechanisms do the rest of the heavy lifting. In other words, until researchers have clearer answers about detoxification, your cutting board and HEPA filter are still the most sensible place to start.