[j1mmie]

This also fits well with the theory that lack of deep sleep increases the risk of alzheimers and dementia:

https://www.medicalnewstoday.com/articles/not-getting-enough...

[clumsysmurf]

Just a few weeks ago this appeared somewhere on HN

https://www.sciencealert.com/study-finds-sleep-may-not-flush...

[SubiculumCode]

Not an expert in the field, but from what I understand the idea is very contentious with sizeable camps on both sides, especially noticeable if you are talking to an Alzheimers scientist, or a immune system scientist.

[gradientsrneat]

Very interesting article! However, the reduction of clearance rate (30%) is not a lot. It is possible the brain produces even less toxins while asleep. And the article also acknowledges there may be an increase in "bulk flow of fluid." All that said, this study was done on mice, so it's hard to draw conclusions.

[ashtami8]

@clumsysmurf, nice catch!

Could it be possible that the coffee lobby is behind this 'counter'-study?, since a relatively simple inference from the OP has catastrophic consequences for the coffee business:

Deep sleep is necessary for the slow electrical waves that clear the brain of waste including amyloid proteins. (Excessive) coffee intake reduces the quality and quantity of deep sleep, thus leading to a build up of waste products including amyloid, resulting in cognitive declines such as Alzheimer's etc. Therefore, coffee intake (indirectly) causes Alzheimer's.

Admitting that last part is suicidal for the coffee business.

[bamboozled]

I've read that exercise negates all of this...

[Tarsul]

I've found out (the hard way) that chronic lack of sleep leads to not having enough energy for intense workouts... (walking is ok though)

[pvaldes]

> exercise negates all of this...

That would be logical taking in mind this article

[ewgoforth]

In what way? It can make up for a lack of sleep?