Plastic has been found in almost every human tissue researchers have looked at

Every few months, another headline lands: "Plastic in blood," "Plastic in the placenta," "A spoonful of plastic in the brain," "Plastic in the arteries of heart-attack patients."

These are not just clickbait. They are peer-reviewed findings from independent research labs, and the list keeps growing. As of July 2026 there is a new one that took the placenta story from “the particles are there” to “here is what they can do.”

Where plastic has actually been found

Blood. In 2022, a Dutch team measured plastic particles in the blood of 17 out of 22 healthy adults ^[1]. Average concentration: about 1.5 micrograms per milliliter. The dominant polymers were polyethylene terephthalate (water bottles, clothing), polystyrene (packaging), and polyethylene (bags, containers). These are the same plastics you probably touched today.

Placenta. Since 2021, three separate studies have found microplastic particles in human placentas, including inside the cells rather than just on the surface ^[2-3]. Particle sizes were mostly in the 5-10 micrometer range, matching signatures from everyday consumer plastics.

Brain. In 2025, a University of New Mexico team measured plastic in postmortem human brain tissue at concentrations higher than in the liver or kidney from the same donors, and about 50% higher in brains from 2024 than in brains from 2016 ^[4]. Under an electron microscope, the particles looked like jagged shards, not the neat spheres used in lab experiments.

Arteries. In 2024, an Italian team followed 257 patients who had surgery to clear plaque from their carotid arteries ^[5]. About 58% had detectable plastic in the removed plaque. Over the next three years, those patients had roughly 4.5 times the risk of a heart attack, stroke, or death compared with patients whose plaque was plastic-free. This was published in the New England Journal of Medicine.

The new evidence: plastic doesn’t just sit there

Until this year, one honest objection to all the detection studies was: okay, they’re there, but does that actually matter? A team from Vrije Universiteit Amsterdam, publishing last month in Molecular and Cellular Endocrinology, gave the clearest answer so far, at least for the placenta ^[6].

They built a laboratory model of the placenta from three cell types (trophoblasts, blood vessel cells, and hormone-producing adrenal cells) stacked in a way that mimics how a real placenta separates mother and fetus. Then they added five different plastic polymers (polystyrene, PMMA, PVC, nylon, PET) at concentrations low enough to be biologically plausible, and watched what happened over 72 hours.

Two things happened.

The plastic crossed. Between 4% and 11% of each polymer moved from the maternal side of the model to the fetal side within three days. PMMA crossed most with 10.7% passing to the maternal side. The others closely followed: polyvinyl chloride (PVC) at 6.5%, polyethylene terephthalate (PET) at 4.2%, and polystyrene (PS) crossed 4.4%. These are not trace levels. For a chronic daily exposure, they add up.

The hormones shifted. The team measured 19 steroid hormones on each side of the model. The plastic exposure lowered several of them, including:

• 17-hydroxy-dihydroprogesterone: down 29% to 36%
• Etiocholanolone: down 22% to 25% (this happened even at the lowest dose tested)
• 17β-estradiol: down 14%
• CYP17 gene expression: down after polystyrene exposure

These are hormones that structure fetal growth and development. The paper’s own conclusion is direct: micro- and nanoplastics cross the placental barrier and disrupt steroidogenesis, raising concerns about endocrine effects during pregnancy.

So the picture for the placenta is now complete. Ragusa 2021: the particles are in the placenta. Ragusa 2022: they are inside placental cells. Van Boxel 2026: they cross the barrier at measurable fractions, and they change the hormones on the other side.

Two things headlines usually get wrong

“Detection means dying from it.” No. Detection means the particles are present. What happens next, whether they cause disease at a given exposure level, is a different, harder question. But the Marfella arterial-plaque paper is the first hard clinical signal that in already-symptomatic patients, plastic in the tissue tracks with a much worse outcome. That is one dataset in one population. It is also not nothing.

“We can’t measure this reliably, so we can’t be sure.” The specific numbers (e.g., micrograms per gram, particles per milliliter) are still being tightened, and there is normal scientific back-and-forth about the exact methods ^[7-8]. But the underlying finding that plastic particles are in these tissues has been reproduced by independent labs using independent methods. The direction is not in dispute. The precision is being sharpened.

hat to actually do

You cannot get plastic out of tissue where it already sits. What you can do is reduce what comes in next.

The three highest-leverage everyday changes are boring and effective:

1. Filter your drinking water. A good under-sink or pitcher filter cuts a large share of the microplastic load in tap water.
2. Stop heating food in plastic.Heat drives leaching of both plastic particles and the additives they carry. This is a bigger source than most people realize.
3. Reduce single-use plastic in the kitchen. Especially plastic wrap and plastic-lidded takeaway containers used for hot food.

None of these are dramatic. That is the point. Microplastic exposure is chronic and diffuse. So is any reasonable response.

Where Winnow fits

Winnow’s probiotic consortium has been shown in laboratory testing to bind micro- and nanoplastics. Winnow supports a healthy gut microbiome while providing additional probiotic strains with plastic-binding capabilities. It is not a detox claim nor a claim about plastic that already reached the blood, placenta, brain, or arteries. Steady support in a plastic-filled world, at the one point where the outside world becomes the inside world.