Dr. Majid Fotuhi

And so when the garbage accumulates around them, they can't function anymore.

And how do you know they can't function?

You feel like a brain fog.

You feel like you're not quite sharp.

And many people actually feel better when you have a good night's sleep, feel much better than if you have not had a good night's sleep.

I mean, even from your own perspective, we can tell that you feel better if you had a good night's sleep.

When these things happen for a year or two, your brain can recover and

things get back to normal.

But when you have had insomnia, which means sleeping fewer than six hours a night for 20 or 25 years, the size of hippocampus, which is the part of your brain from memory, is reduced to almost half its original size.

And that's a major risk for Alzheimer's disease.

Alzheimer's disease happens when this part of the brain called hippocampus shrinks.

Hippocampus is the size of your thumb.

You have one on the right, one on the left.

And this is the ground zero for learning a memory.

When the hippocampus shrinks, your memory worsens.

And when people have had insomnia for two decades, the hippocampus is almost half its original size, and their memory and learning ability is half its original capacity.

Yes.

Your guess was right in that the hallmark of Alzheimer's being these proteins that aggregate at the amyloid plaques and taut angles, which cause inflammation and cause problems.

For a long time, scientists have focused too much on these

and not on these other things that cause brain shrinkage, things like diabetes, obesity, anxiety, sedentary lifestyle, all those things, poor blood flow to the brain, all of those things individually can affect the brain and make it shrink in parallel to plaques and tangles that can shrink the brain.