Given the research we do for this channel, I am no stranger to surprising, sometimes controversial—and occasionally disgusting—claims regarding Alzheimer’s disease.

In a previous video, we explored how something as mundane as earwax buildup—or, more technically, cerumen impaction—could lead to hearing loss and, by extension, cognitive decline.

Today, we’re looking at a physical habit.

It’s often dismissed as a minor social faux pas—and was even the subject of jokes in an old Seinfeld episode. But recent research suggests this common behavior might create a pathway for certain pathogens to reach the brain.

We’re talking about nose-picking—and its potential link to late-onset dementia.

For the companion video, see here:

The Griffith University Study

A team of researchers at Griffith University in Australia published a 2022 study in the journal Scientific Reports. They focused on a bacterium called Chlamydia pneumoniae.

This common airborne bacterium—sometimes called the Taiwan Acute Respiratory Agent—is primarily known for causing bronchitis and pneumonia. However, it has also been detected in a significant number of human brains affected by late-onset dementia.

Using mouse models, the researchers tracked how this bacterium travels. What they found was striking: it can move along the olfactory nerve—from the nasal cavity directly into the brain.

In these models, infection reached the central nervous system within 24 to 72 hours. Once inside, it triggered amyloid-beta deposition—the same protein associated with Alzheimer’s plaques.

One interpretation is that amyloid-beta may function as part of the brain’s immune response to infection. However, if that infection becomes chronic or repeatedly facilitated—potentially through damage to the nasal lining—this process could contribute to neurodegeneration.

In short: this research suggests that certain behaviors might make it easier for pathogens to access the brain.

Connection: The Earwax Analogy

You may remember from our earwax discussion that conductive hearing loss involves a physical obstruction—something like earwax blocking sound transmission.

In a similar way, the nasal epithelium acts as both a physical and immunological barrier.

The Griffith University study found that when this barrier was damaged, infections in the mice became significantly more severe.

Think of the nasal lining as a security checkpoint: if it’s intact, most threats are stopped. If it’s compromised, things can slip through.

Just as we cautioned against inserting objects into the ear canal, scientists now warn that picking—or plucking nose hairs—can damage this delicate lining. That damage may give pathogens a clearer route to the brain.

Why This Matters

As geriatrician Maria Carney noted in our earwax discussion, “most people don’t even realize that they have an issue.”

That lack of awareness is a recurring theme in both Alzheimer’s prevention and detection.

While nose-picking is often associated with children, it remains common in adults. In fact, one study found that about 91% of people admit to it.

I’m curious how that compares with this audience—so I’ve put up an anonymous poll if you’d like to weigh in.

As many viewers know, age alone—especially over 65—significantly increases Alzheimer’s risk.

If we add environmental exposures, such as introducing pathogens through repeated nasal damage, this could represent an additional, potentially modifiable risk factor.

Caveats and Disclaimers

To be clear: this is early-stage research conducted in mice. We do not yet have direct evidence that this pathway operates the same way in humans.

Human trials would be needed to confirm whether a similar mechanism is at work.

And of course, Alzheimer’s disease likely involves multiple contributing factors—including acetylcholine loss, plaque formation through other mechanisms, neurofibrillary tangles, and nutritional or metabolic influences.

So yes—this hypothesis may sound farfetched.

But it is being seriously explored, and it may be worth paying attention to.

Practical Advice and Conclusion

One of the core goals of the Alzheimer’s Proof project is prevention. And unfortunately, there is no single solution—no magic bullet.

What we can do is try to stack the odds in our favor.

Protect the Barrier

Avoid plucking nose hairs and minimize behaviors that could damage the nasal lining. Chronic irritation may increase vulnerability.

Use Safer Alternatives

If needed, consider electric trimmers for grooming. For congestion, saline sprays or nasal irrigation may help. If using a neti pot, always use distilled or properly purified water.

Keep It Clean

If you must manually clear your nose, ensure your hands are clean—before and after. Also keep fingernails trimmed and smooth to reduce the risk of micro-injury.

Stay Aware

Consult a healthcare provider if you experience persistent irritation, bleeding, or signs of infection.

The key takeaway here isn’t panic—it’s awareness.

Small habits, repeated over time, can shape long-term brain health.

And if reducing Alzheimer’s risk comes down—even in part—to eliminating preventable factors, then even small changes may be worth considering.

________________________________________

References:

• David Nield, “Nose-Picking May Have a Surprise Link With Alzheimer’s, Study in Mice Suggests,” Science Alert, April 5, 2026, <https://www.sciencealert.com/nose-picking-may-have-a-surprise-link-with-alzheimers-study-in-mice-suggests>. 
  
• Anu Chacko, Ali Delbaz, Heidi Walkden, Souptik Basu, Charles W. Armitage, Tanja Eindorf, Logan K. Trim, Edith Miller, Nicholas P. West, James A. St John, Kenneth W. Beagley, and Jenny A. K. Ekberg, “Chlamydia pneumoniae can infect the central nervous system via the olfactory and trigeminal nerves and contributes to Alzheimer’s disease risk,” Scientific Reports, vol. 12, no. 2759, February 17, 2022, <https://www.nature.com/articles/s41598-022-06749-9>. 

• “Can Earwax Buildup Cause Memory Loss? Cerumen Impaction & Dementia,” video, Alzheimer’s Proof (YouTube), Oct 24, 2020, <https://www.youtube.com/watch?v=OVnZJuM__mc>.

AT A GLANCE: Amyloid‑β plaques = a hallmark of Alzheimer’s disease; Most drugs target plaques directly

Alzheimer’s may involve a failure of brain “cleanup,” not just toxic buildup.

What if Alzheimer’s isn’t just caused by toxic buildup in the brain — but by the brain’s own cleanup crews being quietly dismantled from the inside?

If you’ve been around the block, when it comes to Alzheimer’s, you probably realize that a primary “pathological hallmark” is the accumulation of – what are called – “amyloid-beta plaques” within the brain.

• AT A GLANCE: What if the problem is impaired clearance—not just plaque formation?

For over a century — since Alzheimer’s was first described in 1906 — drug development has largely focused on stopping plaque formation or clearing plaques after they appear.

And a critical area of this investigation involves taking a close look at the brain’s innate ability to clear these toxic proteins.

Recent research from the Indiana University School of Medicine has identified a specific enzyme that, when it is present, appears to be a factor when someone’s brain-clearing mechanisms go haywire.

And, in this video, we’ll look at a CliffsNotes’ version of the results.

https://www.youtube.com/embed/t0G-diPs2yU?si=lXQ5cl1JulI-IZmt

• AT A GLANCE: IDOL = Inducible Degrader of the LDL receptor controls how many LDL receptors remain on brain cells

The enzyme is abbreviated I‑D‑O‑L, or “IDOL,” short for “Inducible Degrader of the LDL receptor.” That expression (a mouthful, for sure) designates a protein that controls how many LDL receptors survive on the surface of brain cells.

But… what the heck is it? And, more importantly, how would its inhibition (quote, unquote) represent a promising shift in doctors might approach Alzheimer’s treatments?

The Molecular Rôle of “IDOL”

• AT A GLANCE: Receptors = cellular “locks” that trigger actions

To even begin to understand this discovery — and to be perfectly honest, that’s about the most ambitious goal I can realistically aim for — we need to talk about something called a low‑density lipoprotein, or “LDL,” receptor.

First, in the relevant context, a “receptor” is a protein on a cell — or in a cell — that acts like a lock. When the right chemical “key” comes along, that lock opens and tells the cell to do… something.

• AT A GLANCE: LDL receptors pull material into cells for use or disposal

An LDL receptor is one of these locks. Its job is to grab so‑called “bad” cholesterol — LDL — and pull it into cells so it can be used or gotten-rid-of.

Think of it like a trash‑pickup claw that grabs garbage from the streets of the body and pulls it inside for disposal.

• AT A GLANCE: In the brain, LDL receptors help manage APOE and amyloid‑β

In the central nervous system, LDL receptors also play a crucial role in regulating APOE, a protein involved in the transport and clearance of amyloid‑beta.

So far, so good?

• AT A GLANCE: IDOL tags LDL receptors for destruction

Now for this IDOL business.

IDOL is not a receptor itself. It’s a protein that comes along and “tags” LDL receptors for destruction — that’s the “inducible degrader” part of its full name.

• AT A GLANCE: Overactive IDOL à fewer LDL receptors; (-) Amyloid clearance à (+) plaque buildup

It’s like removing the trash‑pickup claws and throwing them away instead of the “bad” cholesterol. Reducing the number of LDL receptors on cell surfaces is a bit like getting rid of trash trucks in the heart of a crowded city. It’s not good.

When IDOL becomes overactive, too many LDL receptors are destroyed, weakening the brain’s ability to clear APOE and toxic amyloid‑beta proteins. This allows plaques to accumulate and neurodegeneration to accelerate.

In effect, an overactive cellular “shutdown switch” disables the brain’s cleanup crews at precisely the moment they’re needed most.

Receptor Inhibitors — and Why IDOL Is Different

• AT A GLANCE: IDOL inhibitors protect receptors; They stop destruction — not signaling

At this point, it helps to understand what scientists mean by a “receptor inhibitor.” Usually, a receptor inhibitor blocks a lock so that even when the correct key shows up, the cell can’t respond. But that’s not quite what’s happening here.

An IDOL inhibitor doesn’t block the lock — it stops the demolition crew from tearing the lock off the door. In other words, inhibiting IDOL prevents LDL receptors from being destroyed, allowing the brain’s cleanup machinery to stay in place and keep doing its job.

IDOL Proteins Aren’t the Problem in and of Themselves

Let’s register a couple caveats.

Number one, it’s important to understand that IDOL proteins aren’t “bad” in and of themselves. They’re normal control mechanisms within the complex anatomy-biology of the body.

And they don’t come from “outside.” Your own cells make IDOL proteins automatically.

• AT A GLANCE: IDOL is a normal control mechanism; Problems arise when it shuts things down too aggressively

Think of their part in in the trash-removal process as akin to that of a “thermostat” that off the air conditioner or furnace when the desired temperature is reached.  When a cell thinks it’s cleaned up enough LDL cholesterol, these IDOL proteins shut down the whole process.

In the context of Alzheimer’s Disease, overactive IDOL proteins lead to a depletion of these trash-removal receptors. In turn, this loss diminishes the brain’s capacity to clear amyloid-beta. And that, researchers, suspect, leads to – or makes worse – the formation of the plaques that lead to neurodegeneration.

Whew!

• AT A GLANCE: Evidence so far: animal + cellular studies

It’s also important to note that this entire IDOL–LDL receptor mechanism has been demonstrated primarily in animal and cellular studies. While the evidence strongly implicates IDOL in Alzheimer’s pathology, human treatments are still in-process.

Research Findings

Neuronal vs. Microglial IDOL

AT A GLANCE: Microglial IDOL removal à little effect; Neuronal IDOL removal à major plaque reduction]

The study in question was led by Dr. Hande Karahan and Dr. Jungsu Kim, who sought to determine which cell types were most responsible for IDOL-mediated damage. Historically, the scientific community focused on microglia — the brain’s immune cells — as the primary drivers of plaque-clearance.

However, using a series of “knockout models,” the Indiana University team found that removing IDOL from microglia had a negligible effect on plaque levels.

• AT A GLANCE: “Knockout” = a gene deliberately switched off to study its function

A “knockout model” is a genetically engineered animal — usually a mouse — in which a gene like IDOL is “switched off” so scientists can see how the brain behaves without it.

They take out a gene to see what breaks — or improves — when it’s gone.

When IDOL was “deleted” specifically from neurons, the results were deemed significant. The researchers observed a substantial reduction in amyloid-beta deposition.

• AT A GLANCE: Lower APOE4 levels observed; APOE4 = strongest genetic risk factor for late‑onset Alzheimer’s

Additionally, the deletion of neuronal IDOL led to a decrease in APOE4 levels. As APOE4 is the most significant genetic risk factor for late-onset Alzheimer’s, this suggests that targeting IDOL could directly mitigate the risks associated with this specific genotype.

Clinical Implications and Synaptic Health

• AT A GLANCE: IDOL inhibition linked to improved ‘synaptic plasticity’; Healthier connections = better learning & memory support

What distinguishes this research from current treatments — such as antibodies that target existing plaques — is its focus on enhancing the brain’s internal environment.

The researchers also observed a second effect – beyond reducing toxic amyloid-beta. This is to say that inhibiting IDOL was also associated with improvements in synaptic plasticity — the brain’s ability to adjust and strengthen connections involved in learning and memory.

It refers to how the brain “rewires” itself.

Conclusion: The Path to Small-Molecule Therapeutics

• AT A GLANCE: Targeting IDOL may improve the brain’s internal environment

From a pharmaceutical perspective, the IDOL enzyme is a highly viable (read: commercially promising) target.

So, the upshot is that drug-researchers believe they may be able to engineer an oral medication capable of inhibiting the trash-removal inhibition!

• AT A GLANCE: Goal: oral drugs that cross the blood‑brain barrier; Less invasive than antibody infusions

From a cost-per-treatment standpoint, this would an advancement over the current method, which requires expensive – and invasive – intravenous infusions required to deliver antibody treatments to try to dissolve plaques.

The Indiana University School of Medicine team is still a “preclinical” phase. Its focus is on screening for “small molecules” that can effectively cross the blood-brain barrier to inhibit IDOL. While further trials are obviously necessary, this research provides a roadmap for a new generation of Alzheimer’s therapies.

For those you still here, thank you for sticking with it! I know it was heavy-going.

If you’d like to dig deeper, here’s a link to the original study — because this is one of those cases where the data itself really is the story.

Researchers have found that a common, Food-and-Drug-Administration-approved sleeping pill might actually reduce the buildup of toxic proteins linked to Alzheimer’s disease. 

Today, we’re diving into the reportage of the science behind this discovery. And we’ll discuss a bit about what it could mean for the future of dementia prevention.

The Study

First thing’s first: The study we’re concerned with was written up in an article titled “Suvorexant Acutely Decreases Tau Phosphorylation and Aβ in the Human CNS,” which was published online in the March, 2023 edition of the scientific journal Annals of Neurology. And it was printed in a hard-copy version in July of the same year.

To understand the study, we first need to understand how the brain ‘cleans’ itself (quote, unquote) during sleep.  

While we sleep, our brain uses something called the “glymphatic system.” Think of it like a biological dishwasher. It flushes out metabolic waste that builds up while we’re awake.

Two of the most dangerous types of “trash” cleared out by this glymphatic system are amyloid-beta and tau proteins. 

Of course, viewers of this channel — not to mention anyone with a basic familiarity of Alzheimer’s — probably won’t fail to recognize these words.

After all, it’s these proteins that, when not cleared effectively, clump together into the notorious “plaques and tangles” that constitute the hallmarks of Alzheimer’s disease. 

This is one reason why chronic sleep deprivation is often cited as a major risk factor — alongside advanced age, of course — for cognitive decline.

Suvorexant

Enter a drug called suvorexant, known by the brand name “Belsomra.”

It’s a type of drug known as an “orexin-receptor antagonist.” Oversimplifying, orexin is a molecule in the brain that keeps us awake and alert. 

The idea is that, by blocking orexin, the drug suvorexant may encourage the brain to transition into sleep.

Researchers at Washington University School of Medicine in St. Louis, Missouri wanted to see if using this specific drug to “promote” or “enhance” sleep could help to lower the levels of the aforementioned toxic proteins.

To this end, and as scientific studies typically do, they took a group of thirty-eight healthy volunteers, aged 45 to 65, and gave them either a dose of suvorexant or a placebo before bedtime. Researchers then monitored the participants’ cerebrospinal fluid over the next 36 hours.

What Happened?

To hear them tell it, the results were striking. 

In the subset of participants who took the higher-than-usually-prescribed dose of suvorexant, levels of amyloid-beta dropped by 10 to 20 percent, compared to the placebo group. 

Even more significantly, the same group saw a drop in “phosphorylated tau” — a form of the tau protein that is particularly closely linked to brain-cell death and Alzheimer’s- disease progression.

What makes this exciting is that it wasn’t just “better sleep” clearing the brain (in some vague sense); it was a specific intervention that seemed to target the very precursors of Alzheimer’s pathology.

Caveats

However, before we get too ahead of ourselves, there are some major caveats. 

This was a very small study, and it only lasted for two nights. Therefore, researchers cannot yet say if taking this medication, long-term, will actually “prevent” dementia, or if the protein levels will stay low once the medication is stopped.

The researchers themselves prefer to refer to this as something more like a “proof-of-concept.” 

Of course, we would want to see much longer trials to decide if the observed reduction in proteins actually translates into a predictable — and reliable — reduction in cognitive decline.

That said, this study confirms that the intersection of sleep medicine and neurology is one of the most promising frontiers in medicine. And it suggests that we might eventually treat sleep not just as a lifestyle habit, but as a clinically significant tool that may help us to maintain brain health as we age.If you’re interested in the full details of the study, click for the ScienceAlert article or for the original paper. We hope you rest a little easier tonight!