Study: Plastic Particles in Brains

Simian Practicalist
Jun 18
2 min read

An article by J. Licinio et al titled “The human microplastic burden and brain health: From measurement to pathophysiology and removal” published on 5 May 2026 discusses concerns regarding so-called microplastics in the human body.

The article is short at less than four pages in total, including references.

First of all, the authors point out that whilst “microplastics” is the commonly used term, “nanoplastics” is more accurate.

Those that cross the blood-brain barrier, accumulate in brain tissue, and lodge within the intracellular compartment of placenta and atheroma are predominantly nanoscale.

There are four mechanistic pathways of plastics damaging the brain:

…oxidative stress and chronic inflammation, endocrine disruption, gut-microbiome injury with consequent gut-brain signaling, and vascular and capillary damage. Each pathway is supported by animal and in vitro evidence, and each converges on outcomes that brain-health professionals recognize from clinical practice. Neuroinflammation, vascular cognitive impairment, mood dysregulation through inflammatory and microbiomemediated routes, and endocrine perturbation of neurodevelopment are familiar territory.

The authors are concerned that even though there is plenty of research that shows plastics in the human body, including the brain, and even a means to remove them, there is the problem of testing and measurement—that is, measuring how various types and sizes of plastics go where and impacts what specifically—in order to formulate a treatment/intervention strategy.

As for research regarding the general impact of plastics on health, a common source is the packaging of ultra-processed foods (UPF).

Lane and colleagues, in ameta-analysis of 385,541 participants, found that higher UPF consumption was associated with a 53% increase in the odds of common mental disorder symptoms, a 44% increase for depression specifically, and a 48% increase for anxiety. Prospective data within the same analysis showed a 22% increase in the risk of subsequent depression.

Amongst others, the authors cite a study by A.J. Nihart et al titled “Bioaccumulation of microplastics in decedent human brains” published on 3 February 2025. This study found microplastics and nanoplastics (MNPs) in the liver, kidney and brain.

Higher concentrations of MNPs were found in the brain than kidney and liver in the samples (at the time of death).

The proportion of polyethylene (PE) in the brain (75% on average) was greater relative to other polymers and compared to PE in the liver and kidney.

The concentrations were generally higher in 2024 than in 2016. Contamination from storage containers for older samples is irrelevant; the point is that plastic exposure has clearly increased such that