Microplastics in the Brain: What the 2025 Study Found and What It Didn't

By Nora WhitleyEditor, Phytomem ReviewUpdated October 18, 20264 min read

In February 2025 a study in Nature Medicine reported plastic particles in human brain tissue, more than in the liver or kidney, and more still in people who had dementia. It became one of the most shared science stories of the year, and it is now the basis of several supplement sales pitches.

The study in brief

The paper is "Bioaccumulation of microplastics in decedent human brains," published in Nature Medicine by a team led by Matthew Campen at the University of New Mexico College of Pharmacy (PubMed abstract).

The researchers looked at tissue from people who had died and been examined by New Mexico's Office of the Medical Investigator. They used three different lab methods to detect and identify plastic particles in samples of liver, kidney and the frontal cortex of the brain. Using more than one method matters, because measuring tiny plastic particles in tissue is hard, and earlier studies were criticized for contamination and false positives.

What they found

Five findings got most of the attention:

1. Plastic was present in all three organs. Most of it was polyethylene, the plastic used in bags, bottles and food wrap.
2. The brain held more than the liver or kidney. That surprised people, since the brain sits behind the blood-brain barrier, which keeps out many substances.
3. It went up over time. Samples from people who died in 2024 contained more plastic than samples from 2016, in both liver and brain.
4. Age, sex and cause of death didn't seem to matter much. The amount was not clearly linked to how old the person was.
5. Brains from people with dementia had even more. In a separate group of people who had been diagnosed with dementia, the plastic collected along blood vessel walls and in immune cells.

Under an electron microscope, the brain particles looked like tiny, sharp flakes, mostly smaller than a micrometer. That image is where the "shards" language in some marketing comes from.

What the study did not show

This is the part that tends to get dropped between the research paper and the headline, and it matters a lot.

It did not show that plastic causes dementia or memory loss. It found an association. The authors themselves call for research to understand exposure, uptake, clearance and possible health effects.

The dementia link may run backwards. In dementia, the blood-brain barrier gets leakier and the brain's clean-up systems work less well. Both could let more plastic in, or stop it from leaving. A brain that already has dementia might collect more plastic as a result, rather than the plastic causing the disease. The study design can't tell these apart.

The samples were small. The comparison across years and the dementia group involved dozens of people, not thousands, all from one US state.

Measurement is still being worked out. Quantifying nanoplastics in fatty tissue like the brain is technically difficult, and other scientists have questioned how precise the absolute numbers are. The direction of the findings is more trustworthy than the exact amounts.

Where the "50%" figure comes from

You may have seen claims that microplastics speed up memory loss "by 50%." I could not find that number in the study. News coverage described the increase in brain plastic between the 2016 and 2024 samples as roughly 50%. That figure is about the amount of plastic, not about memory. Turning it into "your memory declines 50% faster" is a leap the research doesn't support.

Can you get plastic out of your brain?

Nobody knows how, yet. No drug, diet or supplement has been shown to remove microplastics from the brain or any other organ in people. Supplements that claim to "neutralize" or "flush" microplastics are making claims no study has tested.

What people can reasonably do is cut exposure where it's easy, while knowing the benefit hasn't been measured:

• Don't heat food in plastic containers or under plastic wrap in the microwave.
• Drink tap water through a decent filter rather than bottled water by default.
• Store hot or fatty food in glass or stainless steel.

The FDA's page on microplastics and nanoplastics in food summarizes what the agency currently knows, which is that the evidence does not yet show a health risk from levels found in food.

What this means for supplements built on this study

Several memory supplements now use this research in their marketing, Phytomem One among them. The honest reading is that the study shows plastic is getting into human brains and may be worth worrying about, but it gives no support for any product claiming to fix that.

If you are considering one of these products, judge it on the evidence for its ingredients, not on the microplastics story. For Phytomem One, we did that on the ingredients page and in the full Phytomem One review.

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