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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.
**Brain Plastic: How Two Studies Became the Dementia Scare of the Year**
Alex: "Microplastics found in human brains — scientists say they're causing Alzheimer's disease." I saw that headline and genuinely felt my stomach drop, because my nan has dementia, and I think most people have someone in their life they're quietly terrified about.
Bill: And that's exactly why this one spread so fast. Dementia is one of the most feared diagnoses there is, and microplastics are already everywhere in the conversation — in your water, your food, your blood. Combining those two fears into one headline is basically a perfect engagement machine.
Alex: Which is what makes it worth pulling apart properly. Because there are real studies here — actual peer-reviewed research in serious journals — and what they found is genuinely interesting. It's just... not what the headlines said.
Bill: Not even close.
Alex: So, the Nature Medicine paper. February 2025, University of New Mexico. They examined brain tissue from deceased people and measured microplastic concentrations. And they found microplastics in every single brain sample.
Bill: Right. That part's real. And they found that brains from people who had dementia contained significantly more microplastics — we're talking roughly five to eight times higher concentrations.
Alex: I think I said "nearly ten times" when I was reading about this earlier, actually. You're saying five to eight?
Bill: Five to eight, yeah. Still stark. The dementia brains had median concentrations around 26,000 micrograms per gram of tissue. Brains from 2024 samples without dementia, closer to 5,000.
Alex: Right, okay. So — not a rounding error. A real, measurable difference.
Bill: Not a rounding error at all.
Alex: And that's where I want to stop, because this is the bit the headlines swallowed whole. What kind of study is this, actually?
Bill: So this is a postmortem correlational analysis. Which means — researchers examined tissue after people had already died. They weren't tracking living people over time. They measured microplastics in brains that had already developed dementia and brains that hadn't, found a difference, and that's where the data ends.
Alex: And a correlation is not causation.
Bill: Exactly. And here's the thing — the researchers said that themselves. In the paper. Their exact words were, "These data are associative and do not establish a causal role." They went further: "No causality is assumed from these findings."
Alex: They literally wrote that sentence.
Bill: In their own conclusions.
Alex: I genuinely have no idea how you get from that sentence to "microplastics cause dementia" in a headline. I was a journalist for a long time and I still — I don't — I can't follow the logic.
Bill: And then the lead researcher, Dr. Matthew Campen, went on a podcast and said he personally thinks the more likely explanation is the reverse causation. That dementia changes the brain first, and those changes are what let microplastics accumulate.
Alex: Hang on — walk me through that. Because this actually reminds me of something. Didn't we do an episode about the insomnia and dementia research? Where the headlines were saying insomnia causes Alzheimer's, and then when you actually looked at the data, the brain damage was already there before the sleep problems got worse?
Bill: Yeah, yeah — the Mayo Clinic study, I think. Same trap. The disease was causing the symptom, and everyone reported it the other way around.
Alex: It's the exact same structure.
Bill: Completely. And Campen is describing the same thing here. So — dementia does very specific things to the brain over time. It breaks down the blood-brain barrier —
Alex: Which, I mean, the blood-brain barrier is sort of fascinating in itself, right? This incredibly selective membrane that decides what gets into your brain and what doesn't?
Bill: It really is. And there's actually interesting research on how much it degrades as we age even without dementia — it's one of those things that, once you start looking at it, you realize how much it's doing behind the scenes.
Alex: Right, okay, but — sorry, we're getting off track. The blood-brain barrier breaks down in dementia, and then what?
Bill: So it breaks down, the tissue shrinks and atrophies, and the brain's waste-clearance systems get impaired. All of which would logically make it easier for microplastics to get in and stay in.
Alex: So the disease creates the conditions for the accumulation. The plastics didn't necessarily arrive and start the fire — they might be sitting in the wreckage.
Bill: That's Campen's read. His own read, on his own study. He called it a horse-and-cart problem: are we watching plastics drive the disease, or watching disease create somewhere for plastics to end up? He thinks the second one.
Alex: The lead author thinks the headline missed the point of his paper. That's... quite a gap.
Bill: And the gap gets wider when you bring in the second study. The mice.
Alex: Tell me about the mice.
Bill: Okay, so — actually, let me back up for a second, because I want to set this up properly. The mouse study came from the University of Rhode Island, published in September 2025. They exposed mice to microplastics in their drinking water and looked for behavioral changes — memory performance, anxiety levels.
Alex: For how long?
Bill: Three weeks.
Alex: Three weeks.
Bill: Three weeks. But honestly, the duration isn't even the biggest issue. These were not ordinary mice. They were genetically engineered to carry a human gene variant called APOE4, which in people is associated with a three-and-a-half times higher risk of Alzheimer's. These animals were already biologically loaded against them.
Alex: So you've taken mice that were built to be vulnerable to brain problems, added microplastics, and observed that the vulnerable mice struggled more.
Bill: Right.
Alex: And from that we're meant to draw conclusions about healthy humans.
Bill: That's what the coverage did. And here's the part that really should have been the headline — the mice without the APOE4 gene? No effect. Normal. Microplastics only appeared to cause problems in animals that already had a genetic predisposition to cognitive decline.
Alex: So even within the study, it wasn't "microplastics harm brains." It was "microplastics may worsen outcomes in animals already primed for brain problems." That's a completely different claim.
Bill: Completely different. And what the media did was essentially merge these two studies. Neither of which established causation. And the result was "studies show microplastics cause dementia." Just — welded together into one story.
Alex: See, this is the bit that frustrates me most, honestly. When I was covering health stories, editors would push back if you were being too cautious — "but what's the takeaway, what does this mean for readers?" And I understand that pressure. But one study found higher microplastic levels in deceased dementia brains and explicitly said it wasn't causal. The other found behavioral changes in genetically engineered mice after three weeks. Those are not the same thing as "microplastics cause Alzheimer's in humans."
Bill: And then there's a third layer that I find — okay, I'm going to admit, this is the part that got me really excited from a methodology standpoint. Because there are serious questions about whether the measurement technique even produces accurate results for brain tissue.
Alex: Oh, this part. Yes.
Bill: The Nature Medicine study used pyrolysis gas chromatography-mass spectrometry — Py-GC/MS. Legitimate technique. But multiple analytical chemists have flagged that it produces false positives for polyethylene — the most common plastic found in those brain samples — when there's a lot of fat in the tissue.
Alex: And the brain is —
Bill: About sixty percent fat. One of the fattiest organs in the body.
Alex: Right, okay.
Bill: Dr. Dušan Materić, an environmental chemist at the Helmholtz Centre, was quite pointed about this. Said the method is well-known to produce false positives in lipid-rich samples. Called the paper "really bad." Said the results were "very explainable" — as in, explainable by the false positive problem, not by actual microplastics. And a formal response was published in Nature Medicine itself, just a few months later.
Alex: Now, here's where I actually disagree with you slightly. Because you've listed all of this — reverse causation, mice with genetic predispositions, measurement problems — and when you explained the Py-GC/MS issue to me, you almost seemed more excited about that than the causation argument. But I think the causation problem is more fundamental. Even if the measurements are completely accurate, even if every one of those microplastic readings is real — you still haven't shown that the plastics caused the disease. The measurement critique matters, but I don't think it's the most damning thing here.
Bill: Hmm.
Alex: Am I wrong about that?
Bill: No, I — you're not wrong. I think you're right, actually. I got pulled into the methodology question because it's the kind of thing I would have flagged first working with data, you know, "are these numbers even valid?" But you're correct that the causation argument is structurally more important. Because if you can't establish causation, the accuracy of the measurements almost doesn't matter for the specific claim the headlines were making.
Alex: Right.
Bill: Although — I do think the measurement problem matters for a different reason. If we're not sure the concentrations are accurately measured, that also undermines some of the related research in this space. So it's not irrelevant. But as the lead critique of this specific story? You're right. It's the cart-before-horse problem.
Alex: Okay. Good. We agree. Sort of.
Bill: Sort of.
Alex: So when you stack all of it — lead researcher saying he doesn't believe his results show causation, the plausible reverse causality, a mouse study that only showed effects in genetically predisposed animals, and real questions about the measurement technique —
Bill: None of that appeared in the headlines.
Alex: None of it. And I want to be clear — we're not saying microplastics are harmless. They're accumulating in human bodies, that's confirmed across many studies. There's a 2024 paper in the New England Journal of Medicine linking microplastics to cardiovascular inflammation. That's worth watching closely.
Bill: Right. The general concern isn't unfounded. The fact that these particles are in our brains at all is something scientists should be investigating. What's not supported is the specific leap to "microplastics are causing the dementia epidemic." The evidence isn't there.
Alex: And this matters beyond just getting the facts straight. Because when people believe microplastics are actively causing dementia, some of them start spending money — sometimes a lot of money — on detox products and "microplastic cleanses" that companies are already selling. Fear without evidence creates a market for things that don't help.
Bill: The practical upshot: if you want to reduce your exposure as a precaution, that's not irrational. Filtering your water, reducing single-use plastics, not heating food in plastic containers. Reasonable things to do. But you'd be doing them as a precaution, not because we have proof they'll protect your brain from dementia.
Alex: And the researchers who ran the study said that themselves. Their words: "We do not currently suggest that microplastics cause dementia."
Bill: When the scientists are telling you that, maybe that's the sentence that goes in the headline.
Alex: That's what we're here for. We'll keep doing this so you don't have to wade through all of it on your own.