A Functional Medicine Approach to Microplastics

In this episode we discuss:

• Where microplastics accumulate in the body and why size matters
• How exposure happens: food, water, air, and household environments
• Links between microplastics and cardiovascular risk, inflammation, and dementia
• Effects on the gut microbiome and systemic health
• The “Trojan horse” effect: chemical additives like BPA, phthalates, and PFAS
• Ways to reduce exposure in daily life– food storage, cookware, and household materials
• The role of diet, sleep, exercise, and detox pathways
• Targeted support: antioxidants, NAC, sulforaphane, fiber, and binders
• A functional medicine framework for resilience in a toxic environment

Show notes:

• “Microplastics: A real global threat for environment and food safety: A state of the art review” by Ziani, K., et al.
• “Microplastics and nanoplastics in atheromas and cardiovascular events” by Marfella, R., et al.
• “Bioaccumulation of microplastics in decedent human brains” by Nihart, A.J., et al.
• “Plasticenta: First evidence of microplastics in human placenta” by Ragusa, A., et al.
• “Impact of microplastics on the human gut microbiome: A systematic review of microbial composition, diversity, and metabolic disruptions” by Thin, Z.S., et al.
• “Drinking boiled tap water reduced human intake of nanoplastics and microplastics” by Yu, Z., et al.
• “Microplastics and human health: Unraveling the toxicological pathways and implications for public health” by Zhang, X., et al.
• “Antioxidant intervention against microplastic hazards” by Wang, Z., et al.
• Future of wellness 2026 trends report [Press release]
• Learn more about the Adapt Naturals Core Plus Bundle or take our quiz to see which products best suit your needs
• If you’d like to ask a question for Chris to answer in a future episode, submit it here
• Follow Chris on Instagram or Facebook

Hey everybody, Chris Kresser here. Welcome to another episode of Revolution Health Radio. If you’ve been paying attention to health news over the past couple of years, you’ve probably seen the headlines. Microplastics in the blood. Microplastics in the brain. Microplastics in arterial plaque, in the placenta, and breast milk. The Global Wellness Summit named ’tackling microplastics as a human health issue’ as one of its top 10 wellness trends for 2026, calling it a shift from awareness to action. The mainstream coverage has largely landed in one of two camps, either catastrophizing about how we’re all doomed, or dismissing the concern as yet another overhyped scare story.

I want to offer a different frame today. As a functional medicine clinician with deep experience in environmental medicine and toxicology, I’ve spent a long time thinking about how cumulative toxic burden affects human health, how different organ systems respond to chronic low-level exposures, and, critically, what we can do about it. When a study came out in early 2025 showing that microplastics had been found in human brain tissue at concentrations higher than in any other organ measured, I wasn’t skeptical, I was alarmed. That was the appropriate response to the data.

But I want to be clear about what I don’t want you to take from this episode: fatalism. The most pervasive and, in my view, damaging narrative around microplastics is the idea that there’s nothing we can do – that because these particles are everywhere and in everyone, we might as well give up. That conclusion isn’t supported by the evidence and it isn’t helpful. Two studies in particular have significantly shifted how the scientific and medical community thinks about this. A landmark prospective study published in the New England Journal of Medicine in 2024 found microplastics embedded in the arterial plaque of patients undergoing cardiovascular surgery, and those patients had a dramatically higher risk of heart attack, stroke, and death in the years that followed. A 2025 paper in Nature Medicine found microplastics accumulating in human brain tissue, with concentrations rising substantially over just the past eight years. These findings, combined with decades of toxicological research on the chemical additives that plastic carry into the body, have moved this from a speculative environmental concern to an active human health priority. This matters because we have a pattern in environmental medicine where by the time we accumulate definitive proof of causation, significant damage has already been done. Think about lead, cigarette smoke, asbestos. The precautionary case here is strong, the biology is plausible, and the interventions available to us carry broad health benefits well beyond microplastics.

By the end of this episode, you’ll understand how microplastics enter the body and where they accumulate, what the most compelling research actually shows and where the limits of our current knowledge are, why the chemical additives that travel with plastic particles may be the biggest concern, and what you can do right now to meaningfully reduce your exposure and support your body’s ability to process and clear what gets in. Let’s dive in.

Where Microplastics Accumulate In the Body and Why Size Matters

Okay, let’s start with some basic science, because there’s a fair amount of confusion about what microplastics are, how we’re being exposed, and what the body does with them. Microplastics are plastic particles smaller than five millimeters, a spectrum that runs from fragments you can see with the naked eye all the way down to nanoplastics, which are measured in nanometers, roughly two to three times the size of a virus. That smaller end of the size range is where most of the biological concern lies. Nanoplastics can cross barriers that larger particles cannot. They can enter cells, penetrate the blood-brain barrier, and cross the placental barrier, reaching a developing fetus. The larger a particle, the more likely it is to simply pass through the gut and be eliminated in the stool. The smaller it is, the more likely it is to be absorbed into the circulation and deposited in tissue. You’ve probably heard the claim that we ingest the equivalent of a credit card’s worth of plastic every week. That figure has since been challenged as a significant overestimate. More rigorous analysis puts actual human ingestion in the single-digit microgram range, not five grams per week. I raise this not to minimize the concern, but because precision matters if we’re going to take a calibrated approach to this. The credit card figure served its purpose in generating public awareness, but it appears to be wrong, and we should build our understanding on what the data actually supports.

What the data does support is that microplastics have been detected in virtually every human tissue researchers have looked for them. Blood, urine, saliva, liver, kidney, testes, placenta, breast milk, lung tissue, arterial plaque, and most recently, brain tissue. And accumulation is increasing over time. The 2025 Nature Medicine study found that brain tissue samples from 2024 contained roughly 50 percent more plastic than samples collected in 2016. These particles are bioaccumulating, and the trend is moving in the wrong direction.

How Exposure Happens

Exposure comes through three main routes. Ingestion is probably the largest contributor, driven by drinking water and food. Bottled water contains substantially more microplastics than filtered tap water, because the bottle itself is a continuous source of particles. Food contact is also significant. Ultra-processed foods have extensive contact with plastic equipment and packaging through manufacturing, and certain seafood, particularly shellfish eaten whole, can contain high concentrations. Inhalation is the second major route and is often underestimated. Indoor air can have meaningful concentrations of microplastics, shed from synthetic textiles in clothing, carpeting, and upholstered furniture. If you live in a home with wall-to-wall carpet and polyester furnishings, your indoor air quality is a different proposition from someone without them. Urban outdoor air also carries microplastics from tire wear and industrial sources. Exposure through the skin is generally considered the least significant route for most people. Intact healthy skin provides a reasonable barrier against particles larger than about one micrometer, though nanoplastics in damaged or inflamed skin present a different picture.

Microplastics are not simply inert particles. They’re manufactured with thousands of chemical additives designed to impart flexibility, color, stability, UV resistance, and flame retardancy. Many of these additives, bisphenol A, phthalates, PFAS, have well established toxological profiles. And plastic particles, because of their large surface area relative to their volume, are highly efficient at adsorbing environmental pollutants, including heavy metals and persistent organic compounds, and concentrating them. This is the Trojan horse dynamic I’ll come back to because it’s central to understanding the real mechanism of harm.

Microplastics are everywhere, and research links them to heart disease, brain accumulation, and inflammation. In this episode, we break down what the science actually says—and the practical steps you can take today to reduce exposure and support your body’s natural detox systems. #ChrisKresser #microplastics

Microplastics Impact on Cardiovascular Risk, Dementia, and the Gut Microbiome

The two studies I mentioned in the intro have generated more scientific and clinical discussion about microplastics than anything in the preceding decade, so both deserve a close look. The New England Journal of Medicine study, published in March 2024, was the first to directly link microplastics in human tissue to clinical outcomes. Researchers enrolled 257 patients undergoing surgery to remove fatty plaque from their carotid arteries, which are the large arteries in the neck. After surgically excising the plaque, they analyzed it for the presence of microplastics and nanoplastics using gas chromatography, a high-sensitivity analytical method, combined with electron microscopy to visualize the particles directly. Of those 257 patients, 58 percent had detectable polyethylene in their arterial plaque. About 12 percent also had measurable amounts of polyvinyl chloride. The researchers then followed these patients for an average of nearly three years. Patients whose plaque contained microplastics had a four-and-a-half fold higher risk of the combined endpoint of all-cause death, heart attack, or stroke, compared to those whose plaque was plastic-free. That hazard ratio held after adjusting for major cardiovascular risk factors, including diabetes, high blood pressure, elevated LDL, and statin use. The researchers also measured inflammatory markers and found they increased alongside plastic concentrations in the plaque tissue. It’s important to note this study was observational, not a randomized controlled trial. It establishes association without proving causation. The authors acknowledged that unmeasured confounding factors could contribute to the outcome differences. But as one of the accompanying editorials noted, a hazard ratio of 4.5 is quite large, and it’s hard to attribute entirely to residual confounding when the researchers already controlled for the primary cardiovascular risk factors. The finding of inflammatory markers covarying with plastic concentrations is at least biologically consistent with a mechanism.

The Nature Medicine paper from early 2025 asked a different question: are microplastics accumulating in the brain, and if so, at what concentrations? Researchers at the University of New Mexico analyzed post-mortem brain, liver, and kidney tissue from donors whose samples were collected in both 2016 and 2024. Brain tissue showed substantially higher concentrations of microplastics than the other organs. The particles were predominantly polyethylene, and under electron microscopy they appeared as jagged, nanoscale shard-like fragments concentrated in two specific locations– the fatty myelin sheath that wraps around neurons, and the perivascular spaces, the areas around small brain blood vessels. The time trend data was significant. Concentrations in both liver and brain samples were significantly higher in 2024 samples than in 2026 samples. And in a subset of donors with documented dementia diagnoses, plastic concentrations were three to five times higher than brain tissues from individuals without dementia. A letter published subsequently in Nature Medicine raised methodological concerns about contamination controls in the study, and those critiques are worth acknowledging because rigor in analytical chemistry is genuinely important. The study authors responded and partly addressed the concerns. Where the science lands on the specific quantitative estimates remains an open question. But the core finding, that nanoscale plastic fragments are present in human brain tissue, are increasing over time, and appear to correlate with dementia diagnoses, is consistent with findings from multiple other laboratories and warrants serious ongoing investigation.

Separately, a growing body of research is examining the relationship between microplastic exposure and gut microbiome health. Multiple studies in animal models and limited human data suggest that microplastics can shift the balance of gut microbial populations, reducing diversity and beneficial bacteria while creating conditions that allow more pathogenic species to flourish. This matters because a compromised gut microbiome weakens the intestinal barrier, increasing permeability and allowing bacterial toxins and inflammatory molecules to pass into systemic circulation. Given how central the gut is to immunity, metabolism, and neurological function through the gut-brain axis, the downstream consequences of microplastic-driven dysbiosis could extend well beyond the GI tract.

The “Trojan Horse” Effect

So let me offer the framing I find most clinically useful for making sense of all this. The plastic particles themselves are one category of concern. Small particles, particularly at the nanoscale, can enter cells, provoke immune responses, cause physical irritation of the tissue, and in the brain specifically, may interfere with the myelin insulation around neurons and with the glymphatic system’s ability to clear waste. But the chemical payload these particles carry is arguably the more established and better characterized source of harm, because we have decades of human toxicology on the key chemicals involved. Think of it this way, a microplastic particle doesn’t arrive in your body empty. It arrives carrying whatever additives were incorporated during manufacturing, plus whatever pollutants it has picked up from its environment, accumulated through a process called adsorption. When that particle degrades inside tissues or releases its cargo under the physiological conditions of the body, those passengers enter the surrounding environment.

Bisphenol A, or BPA, is the most studied of these. It mimics estrogen, binding to estrogen receptors and interfering with the hormonal signaling that governs reproductive function, thyroid activity, metabolic regulation, and fetal development. The widespread shift to BPA-free products has not resolved the problem because the replacement chemicals BPS and BPF appear to have similar or even greater hormonal activity through different receptor binding pathways. Phthalates, used as plasticizers to make plastic flexible and durable, interfere with testosterone synthesis and have been associated with reduced sperm count and quality, altered ovarian function, and disrupted androgen signaling. PFAS, the per- and polyfluoroalkyl substances sometimes called forever chemicals because of their persistence in the environment and in human tissue, are linked to thyroid disruption, immune suppression, altered lipid metabolism, and elevated cancer risk across multiple organ systems.

At the cellular level, the primary mechanism across most of these exposures is oxidative stress. Microplastics and their chemical additives generate reactive oxygen species inside cells, overwhelming the cellular antioxidant defense systems and leading to mitochondrial dysfunction, DNA damage, lipid peroxidation, and inflammation. This oxidative damage pathway is why antioxidant support is not just a vague wellness recommendation in this context, it’s targeting a specific mechanistic process. The reason I find the Trojan horse frame useful is that it shifts the conversation from ‘should I be worried about plastic particles’ to ‘what is the full biological burden of living in a plastic-saturated environment,’ and the latter is a more tractable and clinically actionable question. We know a great deal about how to support the body’s detoxification systems. We know how to protect against oxidative stress. We know how to support hormone balance when it’s been disrupted by endocrine disruptors. The microplastics problem fits within frameworks that functional medicine has been working with for a long time.

Ways to Reduce Exposure In Daily Life

Okay, now that we understand the science and the mechanisms, let’s talk about what actions you can take to protect yourself and your family. The goal is a practical reduction in burden, not complete elimination, which probably isn’t achievable at this point. Water is the single most impactful lever most people have. Bottled water contains substantially more microplastics than filtered tap water. Switching from plastic bottles to filtered tap water addresses both the source of the water and the container, and it’s one of the highest-return changes you can make. For home filtration, the most effective technology for microplastic removal is reverse osmosis, or RO. RO membranes physically block particles, including nanoplastics, at greater than 99 percent efficiency in independent testing. The well-known limitation is that RO also removes beneficial minerals, leaving water that can taste flat and is mildly acidic. The solution is an RO system with a remineralization stage, which typically adds calcium and magnesium back after filtration. Several systems do this well, including the Home Master and iSpring under sink units, and the AquaTru countertop system, which I find appealing partly because it collects filtered water in a glass carafe rather than a plastic tank.

If a reverse osmosis system is impractical for you, a high-quality multi-stage filter is a meaningful step. The Clearly Filtered pitcher has been independently tested and verified to remove greater than 99.99 percent of microplastics, alongside BPA, phthalates, PFAS, and a wide range of other contaminants. The pitcher, unfortunately, is plastic, but if you don’t store water in it, the exposure to microplastics should be minimal. The company also makes an under-sink, three-stage system using the same proprietary filtration technology. I’ve confirmed with Clearly Filtered that this system likely performs similarly for microplastics because it uses the exact same filtration technology as the pitcher, though the under-sink unit hasn’t yet had a published independent test specifically for this. I use a Clearly Filtered system myself in our home. Whatever you’re drinking from, make it glass or stainless steel, not plastic.

In the kitchen, the most impactful shift is moving away from plastics for food storage. Glass containers, stainless steel, and ceramic are inert and don’t shed particles or leach chemicals. Never microwave food in plastic, including bags or containers labeled microwave safe, because heat accelerates both particle release and chemical leaching significantly. Replacing plastic wrap with beeswax wraps or reusable covers is a simple swap. If you have non-stick cookware with damaged or flaking coatings, replacing it is worth prioritizing, since those coatings are a source of both particles and PFAS. For cooking, using a wooden or stainless steel cutting board rather than plastic ones reduces the particles that can end up in food directly. When it comes to table salt, rock salt and mined salt, including pink Himalayan salt, have the lowest microplastic contamination because they come from ancient deposits largely insulated from modern pollution, while sea salt has higher levels reflecting ocean contamination.

In terms of diet more broadly, reducing ultra-processed food matters both because these products have had extensive contact with plastic equipment and packaging throughout production, and because whole foods generally represent lower microplastic exposure at the point of eating. Shellfish eaten whole can be a meaningful source, given that filter feeders concentrate particles from their environment in their digestive systems. This doesn’t mean you should avoid shellfish entirely, because it does have substantial nutritional benefits and is rich in nutrients that support detoxification. But it’s worth knowing.

For indoor air quality, synthetic textiles are a significant source of airborne microplastics shed from clothing, carpeting, and soft furnishings. Choosing a natural fiber clothing and bedding, cotton, wool, linen, and cashmere, reduces that load. A HEPA air purifier and a HEPA vacuum both meaningfully reduce indoor microplastic concentrations. If you’re doing laundry, wash synthetic fibers at a lower temperature and lower spin to reduce fiber shedding, and you can also use a microfiber catching laundry bag.

The Role of Diet, Sleep, Exercise, and Detox Pathways

Reducing what comes in is the priority. But given that some level of microplastic exposure is probably unavoidable at this point, and that some accumulation is almost certainly present in most adults, it also makes sense to think about supporting the body’s capacity to process and clear what gets through. Before I get into specifics, I want to be precise about the state of the evidence here. There are no clinical trials that have directly tested the elimination of microplastics from human tissue. We don’t yet have a study showing that a specific intervention measurably reduces tissue concentrations of microplastics in humans. What we have instead is a mechanistic knowledge. We understand the pathways by which microplastics cause harm, and we have evidence that certain interventions support those specific pathways. The strategies I am describing here are grounded in that logic, and they carry well established general health benefits that make them worth pursuing, regardless.

The foundation matters most, and it’s not glamorous. A nutrient-dense, whole foods diet provides the vitamins, minerals, and phytonutrients that keep detoxification pathways running at capacity. Adequate sleep is directly relevant, because the brain’s glymphatic system, its primary waste clearance mechanism, is most active during deep sleep. Given that brain tissue shows the highest microplastic concentrations of any organ measured to date, and that the particles accumulate specifically in the perivascular spaces where glymphatic flow operates, sleep quality is not a peripheral concern. It’s central. When I was seeing patients with chronic illness, sleep disruption was almost always in the picture, and it consistently undermined everything else we were trying to do.

Exercise supports clearance through multiple pathways. It enhances lymphatic circulation, which moves cellular debris towards sites of elimination. It improves liver function and bile flow, which are central to processing fat soluble toxins, and it promotes sweating, which appears to help eliminate some plastic associated chemicals. A small study found BPA in the sweat of participants who had no detectable BPA in their blood at all, suggesting that sweat can act as an additional excretion route for chemicals that other pathways haven’t cleared. The evidence on sweating specifically is limited and preliminary, but the risk-benefit ratio of regular exercise is not in question for any other reason, let alone this one. Heat therapy, through sauna or regular hot baths, extends this logic. Both support liver function and provoke sweating. Infrared saunas in particular have been studied in the context of environmental toxin elimination, and while the microplastic specific data is sparse, the biological mechanisms are consistent with benefit.

For antioxidant support, the NRF2 pathway is the primary target because it governs the expression of over 200 genes involved in detoxification and antioxidant defense. Sulforaphane, the active compound in cruciferous veggies and particularly concentrated in broccoli sprouts, is the most potent dietary NRF2 activator we know of. Clinical trials in heavily polluted regions of China showed that a daily sulforaphane-rich beverage significantly increased urinary excretion of benzene and other air pollutants, which share metabolic processing pathways with many plastic derived chemicals. Broccoli sprouts contain roughly 100 times more glucoraphanin, the sulforaphane precursor, than mature broccoli, making them worth using regularly. Eating them raw or lightly steamed preserves the enzyme needed for conversion. Curcumin has also been shown in cell and animal research to activate NRF2 and mitigate oxidative damage from microplastic exposure specifically.

N-acetylcysteine, or NAC, addresses one of the primary cellular mechanisms of microplastic toxicity more directly. Microplastics generate reactive oxygen species inside cells, depleting glutathione, the body’s most critical endogenous antioxidant, and causing mitochondrial dysfunction. NAC raises intracellular glutathione by providing the rate-limiting precursor for its synthesis. It has a long clinical history in medicine, from treating acetaminophen overdose to supporting respiratory and liver function, and animal research has specifically shown that NAC can reverse the mitochondrial damage caused by microplastic exposure. Alpha-lipoic acid works through related pathways, regenerating other antioxidants, including vitamins C and E, and supporting phase two liver detoxification. Both are well tolerated and have established safety profiles.

For gut-based support, dietary fiber supports fecal elimination of particles that haven’t yet been absorbed across the intestinal wall. Maintaining robust gut microbiome diversity with fermented foods, prebiotic fibers, and a wide variety of plant foods supports the intestinal barrier itself, which is the main line of defense against particles crossing into systemic circulation. When it comes to binders, I prefer modified citrus pectin, or MCP, over alternatives like activated charcoal or bentonite clay. Charcoal and clay have broader side effect profiles, particularly around interference with mineral absorption, nutrient uptake, and medication effectiveness, and are better suited to short term use. MCP has clinical evidence for increasing the urinary excretion of heavy metals, including lead, arsenic, and cadmium, which are precisely the metals that plastic particles can carry into the body as adsorbed contaminants. Its modified molecular weight allows it to work both in the gut and systemic circulation, and it’s well tolerated over longer periods with a cleaner side effect profile than most other binders.

A Framework for Resilience In a Toxic Environment

These strategies don’t detox microplastics in a dramatic, direct sense. What they do is reduce incoming exposure, support the liver’s biotransformation capacity, protect against the oxidative damage that microplastics in their chemical cargo cause, and maintain the gut barrier that determines how much gets into systemic circulation in the first place. That’s a coherent, biologically grounded strategy for operating in an environment that’s more plastic contaminated than anything human biology evolved to handle.

Something I’ve observed across many years of environmental medicine is that the most counterproductive response to real and unavoidable toxicological exposure is despair. When the evidence of harm is clear and the source of exposure feels inescapable, there’s a pull toward either panic or resignation, and neither serves us well. Human beings evolved with environmental toxins. Our detoxification systems exist precisely because our ancestors faced chronic chemical challenges from plants, fungi, smoke, and microbial metabolites. What’s changed is the scale and the chemical novelty of modern exposures, not our fundamental capacity to respond to them. The body is not passive in the face of microplastics. It’s working continuously to process, sequester, and eliminate what it can. Our job is to give it the conditions and resources it needs to do that work well, and to reduce the incoming burden wherever we can. Reducing your exposure to microplastics is genuinely achievable. Probably not to zero, but meaningfully. And supporting the detoxification pathways that handle what gets through is something you can start today with steps that benefit your health and every other dimension as well. That’s the framing I’d encourage you to carry forward.

Thanks for listening, everyone. You can find show notes and links to all the studies I mentioned at ChrisKresser.com. If you have questions about this episode or suggestions for future topics, head over to ChrisKresser.com/podcastquestion and leave me a message. I read all of them, and your questions help shape the content I create. Until next time, be well.