Can microplastics in the bloodstream cause blood clots in the brain?

What's actually in it

Microplastics enter your bloodstream from your gut after you swallow them with food, water, and beverages stored in plastic. Once in the blood, these particles circulate throughout your body, including to the brain. Polystyrene, polyethylene, and polypropylene particles have all been detected in human blood samples.

The brain has some of the smallest blood vessels in the body. Microplastic particles that flow freely through larger vessels can get stuck in these narrow brain capillaries.

What the research says

A 2025 study in Sci Adv injected fluorescent microplastics into the bloodstream of mice and tracked where they went. The particles traveled to the brain and physically blocked small blood vessels, causing cerebral thrombosis (brain blood clots).

The blockages reduced blood flow to brain tissue and triggered neurobehavioral abnormalities in the mice, including changes in movement and coordination. The damage was visible on brain imaging and confirmed by tissue analysis.

This is one of the first studies to show that microplastics can cause mechanical harm in the brain, not just chemical toxicity. The particles literally clog the plumbing. While this was an animal study, it raises serious questions about long-term microplastic exposure in humans. Reducing plastic food and beverage contact is the primary way to lower the amount of microplastics entering your bloodstream.