This Study Completely Changed How I See This Cholesterol Drug
A surprising study suggests ezetimibe—a common cholesterol drug—may reduce Alzheimer’s risk via an unexpected brain mechanism. Not a cholesterol story, but a scientific plot twist worth knowing about.
As a neuroscientist by training—with a particular fascination for cholesterol and lipidology—the paper I just read stopped me in my tracks.
Some papers are “shocking.” This one felt like being dropped into a bathtub full of supercharged electric eels.
Here’s the punchline: ezetimibe—a relatively benign, widely used cholesterol-lowering drug—may help prevent Alzheimer’s disease.
That idea comes completely out of left field.
Ezetimibe is generally thought of as a gut drug. It works by blocking cholesterol absorption in the intestine, prompting the liver to compensate by upregulating LDL receptors and pulling cholesterol particles out of circulation.
So, what is it doing in the brain?
It’s as if all of medicine has been looking at ezetimibe as Bruce Wayne… when in reality, it’s also Brain Batman.
And today, I’m going to show you Brain Batman.
The study, published in Aging Biology, was not designed to look for benefits of cholesterol-lowering drugs.
Instead, the researchers performed a hypothesis-naive screen—a broad, unbiased search for existing compounds that might interrupt a microscopic protein interaction implicated in Alzheimer’s disease and other neurodegenerative disorders.
Protein Aggregation Is a Hallmark of Alzheimer’s Disease and Dementia
Before we go further, I need to pause briefly for some essential neuroscience.
Most neurodegenerative diseases are driven, at least in part, by abnormal protein aggregation.
Think amyloid plaques and tau tangles in Alzheimer’s, or alpha-synuclein accumulation in Parkinson’s disease. When proteins clump together in the brain, neurons suffer—and eventually die. The brain degenerates as a result.
Certain protein–protein interactions accelerate this process.
One particularly intriguing interaction occurs between a scaffolding protein called 14-3-3 (yes, that’s really its name… sorry, I didn’t name it) and hexokinase, an enzyme involved in carbohydrate metabolism.
If you went to medical school, you probably learned about 14-3-3 in the context of Creutzfeldt–Jakob disease—a devastating, universally fatal neurodegenerative condition that causes rapid onset dementia and death. It’s caused by infectious misfolded proteins called prions, and the one-year survival rate is only 30%. (Below left: Creutzfeldt–Jakob disease brain.)
Anyway, 14-3-3 plays an important, albeit underappreciated role in other neurodegenerative diseases like Alzheimer’s too.
Under normal circumstances, hexokinase 1 sits happily on the mitochondria.
But under pathological conditions, it can detach, bind to 14-3-3, and contribute to protein aggregation, cellular dysfunction, and ultimately neurodegeneration. (Below right: hexokinase binding to 14-3-3.)
Still with me?
The key points are:
Alzheimer’s disease and related dementias are partly a result of protein misfolding.
The proteins 14-3-3 and hexokinase, known to be involved in brain disease and metabolism, can clump and may contribute to dementia.
Researchers Screen for Existing Medications to Decrease Protein Aggregation
So, the researchers examined post-mortem human brain tissue—specifically the hippocampus, the memory center most affected in Alzheimer’s disease.
There, they found extensive clumping of hexokinase and 14-3-3.
So, they did something clever…
They ran a screen of FDA-approved drugs to see which ones could disrupt this interaction.
Six drugs emerged. One of them was ezetimibe.
They pursued ezetimibe further because it can cross the blood–brain barrier and has an excellent safety profile.
And as another key detail: it was the only cholesterol-lowering drug that showed up in the screen. Not statins. Not PCSK9 inhibitors. Not bempedoic acid. Just ezetimibe.
To emphasize: the researchers were not hunting for extra perks of cholesterol medications.
They weren’t chasing lipid biology at all. They simply asked, “What FDA-approved tools do we already have that might interrupt this neurodegenerative protein interaction?”
And ezetimibe happened to raise its hand.
To return to our analogy: it’s like bumping into Batman, ripping his mask off—and realizing, with some disbelief, that it’s been Bruce Wayne all along.
Now, we get to the fun part… the fighting crime in the brain part…
In the remainder of this letter—available to StayCurious Premium members—we will dive deep into:
What ezetimibe does in the brain
Amyloid
Tau
Autophagy
The available human data, and a truly stunning statistic
Key caveats, limitations, and clarifications
What I’m considering now, and why
My current Alzheimer’s prevention stack
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