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Comment by ErikCorry | Hacker News Reader

If you are looking for a mechanism for why a healthy vascular system protects against alzheimers there's a pretty good candidate here.

https://www.youtube.com/watch?v=He6HMnMbxAc#t=15m09s

My TL;DW is:

* Most neurodegenerative diseases are associated with a buildup of proteins.

* The brain does not have the lymphatic system which cleans waste proteins out of other organs.

* Instead it has cerebro-spinal fluid, which may have some of the same function.

* There's no "CSF-heart" that pumps CSF around the brain.

* Instead the pulse in the arteries has an indirect pumping effect because the arteries in the brain are embedded in CSF.

* Therefore having a healthy pulse/blood circulation serves to help clean the brain.

* But only when you sleep, so don't skimp on the sleep time HN-readers!

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As a sleep-tech founder, I completely agree with the "don't skimp on sleep" part.

* The brain doesn't work on the lymphatic system, but on the glymphatic system [1] * The glymphatic clearance mostly occurs in slow wave sleep, and linked to slow oscillations (just happens to be the function of sleep we are focusing on at https://soundmind.co) [2]

1 - https://neuronline.sfn.org/scientific-research/understanding....

2- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698404/#:~:tex....

Seems logical then that people who develop alzheimers may have a dysfunction in this part of their sleep cycle no? Or could just be simple insomnia and years of lack of sleep

Current belief is both.

The reason you get Alzheimer's at a later stage in life is because as we age sleep degrades, a big part of this degradation is that we get less slow wave oscillations as we age. Less SWOs, means more build up of amyloids.

Years of lack of sleep also leads to build up of amyloids.

Of course this is only meaningful if the amyloid Alzheimer's connection is solved.

> * The brain does not have the lymphatic system which cleans waste proteins out of other organs.

The brain has a lymphatic system:

https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.120.31849...

Listening to matthew walker speaking on joe rogan, he said there was a huge correlation between getting little sleep and getting alzheimer's.

I also think having good circulation is important. I also remember reading that people who took viagra had lower chances of getting alzheimer's as well. viagra helps with circulation.

(so, sleep well and exercise)

I also find it amusing the article doesn't point to lifestyle changes as a possible answer, but to a possible drug solution :)

I thought most of the claims of that book had been debunked.

I don't know... but there are some articles here:

https://www.nih.gov/news-events/nih-research-matters/sleep-d...

https://www.nih.gov/news-events/nih-research-matters/viagra-...

Here's the debunking: https://guzey.com/books/why-we-sleep/

Viagra is also a direct neuroprotectant and phosphodiesterase(5 I think) is implicated as influencing intelligence through a GWAS.

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