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Truth Seekers: Where Data Meets Reality
Tired of sensational headlines and conflicting health advice? Join Alex Barrett and Bill Morrison as they cut through the noise to uncover what scientific research actually says about the claims flooding your social media feed.
Each week, Alex and Bill tackle a different health, nutrition, or wellness claim that everyone's talking about. From "blue light ruins your sleep" to "seed oils are toxic," they dig into the actual studies, examine the methodologies, and translate the data into plain English.
No agenda. No sponsors to please. No credentials to fake. Just two people committed to finding out what's really true by going straight to the source—the research itself.
Perfect for anyone who's skeptical of influencer health advice but doesn't have time to read every scientific study themselves. New episodes drop regularly, delivering clarity in a world full of clickbait.
Question everything. Verify with data. Find the truth.
Disclaimer: Truth Seekers provides educational content based on published research. Nothing in this podcast should be considered medical, financial, or professional advice. Always consult qualified professionals for decisions affecting your health and wellbeing.
**Microplastics in Your Brain: The Alarm That Wasn't**
Alex: Right, so apparently we all have the equivalent of five bottle caps worth of plastic floating around in our brains, and it's causing dementia. That's what I've been seeing everywhere this week.
Bill: Yeah, the headlines have been wild. "Alarming levels," "scientists sound the alarm," "disturbing discovery." And here's the thing—there actually is a real study behind this, published in Nature Medicine, which is a top-tier journal.
Alex: Which makes it worse, doesn't it? Because people see that and think, brilliant, it's real science, must be true. I saw my aunt sharing articles about this with genuinely worried messages.
Bill: And I get why people are worried. The study found microplastics in human brain tissue at concentrations seven to thirty times higher than in liver or kidney tissue. That's a real finding.
Alex: Hold on, seven to thirty times higher? That does sound quite alarming.
Bill: It does until you ask the question that nobody in the headlines bothered with—is that amount actually harmful? But we'll get there. Let me walk through what they actually did, because the methodology is solid.
Alex: Please do, because I'm trying to figure out where the wheels came off between the research and the reporting.
Bill: So this was a postmortem study—they analyzed brain tissue from 43 deceased people. They used this technique called pyrolysis gas chromatography-mass spectrometry, which basically breaks down the tissue and identifies plastic polymers.
Alex: And they found plastic in all the samples?
Bill: Pretty much. The 2024 samples had a median concentration of about 4,900 micrograms per gram of brain tissue. For comparison, liver samples had about 430 micrograms per gram. So yeah, the brain had way more.
Alex: That's the bit that's been everywhere—"your brain is accumulating plastic." And they also found it's gotten worse over time?
Bill: Right. They compared samples from 2016 to samples from 2024, and there was roughly a 50% increase over that eight-year period. That tracks with rising environmental plastic pollution.
Alex: So microplastics are in our brains, concentrations are rising, and brains have more than other organs. I'm still waiting for the part where this isn't concerning.
Bill: Here's where it gets interesting. They also looked at twelve people who had died with dementia—mix of Alzheimer's, vascular dementia, and other types. Those brains had about ten times more microplastics than the brains of people who died without dementia.
Alex: Ten times more. And that's where all the "microplastics cause dementia" headlines came from.
Bill: Exactly. National Geographic ran with "alarming levels found in human brains," and the university's own press release said these levels "could cause neurodegenerative disease."
Alex: But here's what I'm wondering—and maybe I'm being too skeptical—but finding more plastic in dementia brains doesn't automatically mean the plastic caused the dementia, does it?
Bill: That's exactly the right question. And actually, the researchers themselves addressed this directly in the paper. They wrote, and I'm quoting here, "these data are associative and do not establish a causal role for such particles affecting health."
Alex: Sorry, they said what?
Bill: They explicitly stated that their findings don't prove causation. They went further—they said that dementia causes atrophy of brain tissue, impairs the blood-brain barrier, and reduces clearance mechanisms, so "no causality is assumed from these findings."
Alex: Right, so the researchers put in writing that they're not claiming microplastics cause dementia, and somehow the headlines still said microplastics could cause dementia.
Bill: Welcome to science communication in 2025.
Alex: That's just maddening. Because what you're actually saying is that the dementia itself might be why there's more plastic there. The disease process lets more plastic accumulate.
Bill: Exactly. Think about it—dementia damages the blood-brain barrier, which is your brain's security system. It also messes with the glymphatic system, which is basically how your brain takes out the trash. If those systems aren't working properly, stuff accumulates.
Alex: So it's like saying people with flooded basements have more water damage. The flood caused the water to accumulate, not the other way around.
Bill: Perfect analogy. This is what we call reverse causation. The thing you think is the cause is actually the effect.
Alex: But you can't write a headline that says "dementia allows plastic accumulation." That's boring. That doesn't get clicks.
Bill: And this is where study design really matters. This was a cross-sectional postmortem study—they looked at brain tissue from people after they died. That's a snapshot. You can't establish cause and effect from a snapshot.
Alex: Because you'd need to track living people over time, see who accumulates plastic, then see who develops dementia later.
Bill: Exactly. That would be a prospective cohort study. You'd need to measure plastic accumulation before symptoms appear, control for other risk factors, look for a dose-response relationship—do people with more plastic get sicker? None of that exists in this study because it can't. The study design doesn't allow for it.
Alex: Right, but the thing is, most people reading these headlines don't know what a cross-sectional study is. They just see "Nature Medicine" and "University of New Mexico" and assume it's definitive proof.
Bill: And that's the responsibility gap. The researchers were careful. They included limitations, they said causation isn't established, they called for more research. But somewhere between the paper and the public, all that nuance disappeared.
Alex: Let me guess—the university press release?
Bill: The university press release framed it as "alarmingly high levels" that "could cause neurodegenerative disease." They quoted the senior author, Matthew Campen, saying "I never would have imagined it was this high" and "I don't need to wait around thirty more years to find out what happens if the concentrations quadruple."
Alex: Which is emotional language that completely bypasses the fact that there's no evidence of harm at current levels.
Bill: Right. And check this out—CBS News actually did better journalism than the university. They included a quote from the researchers saying "the study was not designed to prove whether that was the cause of symptoms—it may be the reverse, that the disease process allows more accumulation to happen."
Alex: So the information was available. Some outlets just chose not to use it.
Bill: The Science Media Centre got expert reaction from a professor at Queen's University Belfast who said the findings are "primarily associative" and we need "refined analytical techniques and expanded research to fully understand the health implications." That's the responsible framing.
Alex: But it's so much less exciting than "scientists sound the alarm after disturbing discovery," which is what Yahoo News went with.
Bill: Here's the other problem nobody talks about—even if we know microplastics are in brain tissue, we have no idea what level is actually dangerous. The paper gives us concentrations in micrograms per gram, but there's no threshold for safe versus unsafe.
Alex: Some articles tried to make it relatable by saying it's like five bottle caps worth of plastic, but that's meaningless without context.
Bill: Completely meaningless. Aluminum accumulates in tissue too, and we use aluminum cookware safely. Mercury accumulates in fish, but small amounts don't harm most people. The dose makes the poison, and we don't know the toxic dose for microplastics in humans.
Alex: So what do we actually know? Because there is a real study here, and microplastics are a real thing in the environment.
Bill: What we know for certain: microplastics are present in human brain tissue, concentrations are higher in brains than in other organs, and concentrations have increased from 2016 to 2024. Those are real findings worth investigating.
Alex: And what we don't know?
Bill: Whether they're causing any harm. Whether current levels pose health risks. Whether the association with dementia is causal or reverse-causal or just coincidental. We don't have dose-response data, we don't have clinical outcomes, we don't have mechanism proof.
Alex: This is one of those situations where "we found something" got reported as "it's hurting you," and those are completely different statements.
Bill: And it matters because this is how public trust in science erodes. People read "microplastics could cause dementia," they're terrified, then later when nothing comes of it, they think scientists were crying wolf.
Alex: Or worse, they think scientists are always exaggerating, so they stop paying attention to actual threats.
Bill: The frustrating part is that microplastics are worth studying. Animal studies suggest potential for harm at high doses. We should understand transport mechanisms, we should fund research into health effects. But jumping from "we detected it" to "it's dangerous" skips about ten years of necessary research.
Alex: What should people actually do with this information?
Bill: Honestly? Be aware that microplastics are in the environment and in our bodies, which we've known for a while. Reduce plastic use where practical—that's good environmental policy regardless. But don't lose sleep over the plastic supposedly causing brain disease, because that's not what the evidence shows.
Alex: And when you see headlines like this, ask whether the study actually measured harm or just measured presence. Because finding something in tissue is where research begins, not where it ends.
Bill: The researchers themselves said they need "refinements to analytical techniques, more complex study designs, and much larger cohorts" before they can say anything about health effects. That's honest science. The headlines just weren't honest communication.
Alex: This is why we do this. Real research got turned into fear-mongering, and the people who suffer are both the researchers who did careful work and the public who got misinformed.
Bill: And the real story—that our brains might have imperfect filtration systems for environmental contaminants, which is worth understanding—that got lost in the alarm.
Alex: Next time you see "scientists sound alarm," maybe check whether the scientists actually sounded an alarm or whether that was an editorial choice.
Bill: And remember: correlation isn't causation, especially when reverse causation is sitting right there as the more likely explanation.