Martin Picard says Alzheimer's isn't caused by amyloid plaques, it's an energy disorder

The protein gunk theory of Alzheimer’s gets treated here like an old sofa dragged to the curb. Martin Picard, talking on The Diary of a CEO, says the familiar story that amyloid plaques and tau tangles cause dementia is not just incomplete, but wrong.

that is not the truth

That is the kind of sentence that makes a podcast clip sprint barefoot across Instagram. It also needs a seatbelt. Picard is not some wellness cowboy yelling at a PET scan. He studies mitochondria, the tiny energy machinery inside cells, so of course his theory of Alzheimer’s disease starts with fuel, flow, resistance, and breakdown. Still, the move from “amyloid is not enough” to “amyloid is not the truth” is a big leap in a lab coat.

The plaque theory gets demoted

Picard’s case is simple and sharp. Some people have Alzheimer’s symptoms without visible protein deposits. Some people have lots of amyloid plaques and tau tangles and still think normally. To him, those mismatched cases blow up the clean causal story most of us absorbed through decades of news coverage, drug ads, and reassuring diagrams of a brain slowly being colonized by bad confetti.

You can have people zero protein deposit in the brain and they have full-blown Alzheimer’s and dementia. And you have the other extreme people with loads of amaloid plaques and towangles completely normal cognition.

The fair read: Picard is right to attack the cartoon version. Alzheimer’s research has spent years wrestling with the fact that amyloid burden and symptoms do not line up neatly in every patient, and recent anti amyloid drugs have produced modest benefits, not cinematic reversals. The less fair version would be to toss plaques into the medical junk drawer. Biology is rarely that obedient. Plaques can be markers, contributors, consequences, or accomplices without being the lone villain.

His real villain is glucose traffic

Picard’s replacement theory is that dementia is a disorder of energy. In early disease, he says, affected brain regions may burn more energy as they struggle to compensate. Later, they become hypometabolic, meaning they burn less. That is when memory, planning, emotional regulation, and the rest of the fragile human operating system begin to sputter.

my hunch is that Alzheimer’s and dementia more generally is a disorder of energy and specifically it’s a disorder of you know increased energy resistance

This is where the phrase “type three diabetes” enters, with all the subtlety of a TED Talk title. Picard says that in dementia, the brain is burning less energy and glucose has a harder time getting inside. Push too much sugar through the system for too long, he argues, and cells protect themselves by becoming resistant. The metaphor is electrical, almost kitchen appliance scary: jack up the voltage on a delicate lamp and eventually something starts to fry.

There is a reason this lands. It gives people something to do. Move more. Eat less sugar. Stop pretending the office muffin is a personality trait. Picard ties physical inactivity, overeating, diabetes, and Western diets to worse energy flow, then points to ketones as a cleaner path into the brain. He is careful in one place, admitting he does not know the full literature on hunter gatherer dementia rates. Steven Bartlett then reads out claims about the Hadza and rural populations, and the podcast glides a little too smoothly from “interesting correlation” to “case closed against the Western breakfast aisle.”

ketones can uh, you know, enter the brain and be metabolized more easily and can even kind of improve cognition

The diet advice is less shocking than the dementia claim

Once Picard gets from dementia to food, the episode becomes more familiar, intermittent fasting, fewer snacks, a smaller eating window, skepticism toward breakfast, and the idea that most of us are eating for boredom, stress, or reward rather than hunger. His mitochondrial framing gives the advice a fresh paint job, but the car is parked in the same lot as every modern metabolic sermon.

The strongest version of Picard’s claim is not that sugar personally mails you Alzheimer’s. It is that dementia should be understood through metabolism as much as pathology slides. That is useful. It challenges the old plaque fairy tale without replacing it with a cereal box morality play.

If Picard is right, the question for listeners is brutally practical: are you treating your brain like an organ with an energy budget, or like a cloud account with unlimited storage?