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Comment by comboy | Hacker News Reader

Somebody on HN recommended "Why do we sleep" by Matthew Walker a few weeks ago. There are references in this book strongly linking lack of sleep to Alzheimer's (diabetes too btw). Maybe somebody else can dig them up I don't have the book at hand, but I echo that previous commenter sentiment: if you are only going to read one book this year - make it this one.

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Excellent book! I'm only halfway through and it's already influenced the way I treat sleep. Among the most important takeaways is that diet, exercise, and sleep are commingled (as is their effect on disease and disease progression. Diet and exercise affect sleep quality; sleep quality affects dietary cravings and the ability to exercise; and so on. When one of these three pillars (diet, exercise, sleep) is strengthened/compromised, the others may be strengthened/compromised. By simply choosing to do things during the day that will improve your sleep quality at night, you're checking many of the boxes of a healthy lifestyle.

Would you also think that this book is interesting for people with a normal sleep pattern?

I haven’t read the book cover to cover, but I’ve heard him talk and read summaries. If it’s something you’re interested in, he’s definitely an authority worth listening to. It can also be very useful to diagnose/help friends and family that might struggle more with sleep and not even realize that it’s the downstream source of their problems

There's a lot of stuff in there, and it is very compelling, but there is really only one take-away from it:

Get lots of sleep.

The book is mostly helpful for people who try to "optimize" things or rationalize why they don't need to follow the rules. He debunks all of the excuses.

If you already get enough sleep, then you don't need the book.

You're on HN. You've got a curious mind. Isn't that an interesting question? Why do we sleep? There's been some good progress on trying to answer that. It doesn't just have to be some binary answer, there's a lot going on there.

If you're pragmatic then increasing quality of your sleep may make it worth reading.

Yes, if you have any interest in sleep or the role it may play in the onset or progression of diseases like Alzheimer’s, cancer, cardiovascular issues, diabetes, etc.

I’m only midway through it, but I could see how some of the material could seem redundant or sensationalized if you’re not at least somewhat interested. However, the author does a great job of summarizing studies and presenting data when something seems like it could be sensational. E.g., The heightened rates of heart attacks, car accidents, etc. the day we ‘spring forward’ and lose an hour of sleep in the U.S. for DST (whereas fewer cardiac events, accidents, etc. happen when we ‘fall back.’)

Sleep time is the only time almost everybody in modern society isn't eating/digesting something. Maybe it has some of the effects of fasting? As it is also has been noted to have good effect in treatment for Alzheimer¹ and Diabetes².

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5712566/

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394735/

An odd claim. I would expect that we are still digesting during sleep. Especially since most folks used to nap mid day. (Eating is a fair claim.)

I remember that article being posted on several sites months ago, stating that sleep might clean out many of the chemicals that would otherwise lead to plaque buildup. Here's the NPR version, but if you do a search you'll find several editorials on the same study:

https://www.npr.org/sections/health-shots/2013/10/18/2362118...

+1. I made the original comment on the other thread [1], and repeat here for others: if you read only one book this year, let me strongly recommend you consider this one ("Why We Sleep").

Here's an interesting paragraph, pertinent to the discussion of Alzheimer:

"As we learned ..., sleep quality - especially that of deep NREM sleep - deteriorates as we age. This is linked to a decline in memory. However, if you assess a patient with Alzheimer's disease, the disruption of sleep is far more exaggerated. More telling, perhaps, is the fact that sleep disturbance precedes the onset of Alzheimer's disease by several years, suggesting that it may be an early-warning sign of the condition, or even a contributor to it.

Following diagnosis, the magnitude of sleep disruption will then progress in unison with the symptom severity of the Alzheimer's patient, further suggesting a link between the two. Making matters worse, over 60% of patients with Alzheimer's disease have at least one clinical sleep disorder. Insomnia is especially common, as caregivers of a loved one with Alzheimer's disease will know all too well."

The author goes on to discuss the studies his team did in testing the hypothesis of amyloid buildup in the brain (particularly in the frontal lobe, which regulates your sleep) would impact the quality of sleep, and reduce NREM sleep - which is crucial for memory formation and retention.

So even if the amyloid hypothesis doesn't explain the onset of Alzheimer, there's enough evidence to claim that amyloid plaques may be associated with the loss of deep sleep, and damage your memory.

Now the most interesting part is where the author claims the opposite: that lack of sleep is correlated with amyloid buildups, as it disrupts the function of glymphatic system within the brain.

[1] https://news.ycombinator.com/item?id=17381235

Yup it was you. Thanks for a great recommendation.

Lack of sleep is linked to a miriad of health problems but I’m not convinced it’s a causal factor for Alzheimers.

Not causal, but important to clear beta-amyloid. We've done some interesting imaging studies in our center @UCSF showing radiolabelled beta-amyloid is decreased with proper sleep and exercise. The direct imaging evidence is convincing.

Likely not causal, however, we just know that these two lifestyle factors trigger cleanup processes in your body.

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