Consumer plastics can release billions of micro- and nanoplastics. For example, the normal and intended use of plastic food packaging has been found to create micro- and nanoplastics, including baby food packaging. The small plastic particles have been detected in many human tissues, including in the placenta, testes, lungs, and in the brain, indicating that they are taken up by humans. Furthermore, micro- and nanoplastic exposure has been associated with disease outcomes such as autism spectrum disorder, cancer, and reproductive health conditions, but mostly in small sample size studies or cell-based or whole animal tests. Yet, significant knowledge gaps remain, hindering reliable human health risk assessment.
Using a larger cohort of 113 donors with brain tumors and five healthy donors, Runting Li from Capital Medical University, Beijing, China, and co-authors report the presence of micro- and nanoplastics in 99.4% and 100% of the samples, respectively. In their article, published on April 20, 2026, in the journal Nature Health, they explore potential pathways by which plastic particles may enter the brain by comparing levels across different brain tissue types.
The researchers found that microplastic abundance “was significantly higher” in the peri-glioma brain tissue (the tissue surrounding a brain tumor) than in healthy brain tissue, suggesting that a disrupted blood-brain barrier (BBB) in patients with tumors may facilitate plastic particle entry. The role of an intact BBB as a protective barrier against micro- and nanoplastics is further supported by the observation that extra-axial tissue (located outside the BBB) in healthy samples contained more particles than tissue protected by the BBB.
Nanoplastics (< 1 µm) were more commonly detected throughout all samples than microplastics (>1 µm), indicating that smaller particles appear to reach the brain more easily. Interestingly, glioma (tumor) tissue contained larger microplastic particles than the surrounding peritumoral brain tissue. For their study, the scientists collected the brain tumor tissues during surgery from living patients, while healthy brain samples were taken within six hours of death.
Based on a survey of donors of brain tumor samples, the main exposure sources associated with higher micro- and nanoplastic levels were medical injections, cosmetic application, and plastic food packaging use.
While the study provides initial insights into potential entry pathways of micro- and nanoplastics, further research is needed to clarify how these particles enter and move within the brain, and whether they contribute to disease development or rather accumulate because of underlying pathology.
Reference
Li, R. et al. (2026). “Microplastics and nanoplastics in brain tumours and the healthy human brain.” Nature Health. DOI: 10.1038/s44360-026-00091-4
This article was originally published by Lisa Zimmermann at the Food Packaging Forum.
