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Poor Sleep Linked with Future Amyloid-β Build Up (the-scientist.com)
125 points by northpoleescape 2038 days ago
6 comments

I'll just note that the link between amyloid and alzheimers isn't concrete and is actually an incredibly controversial area of research[0]. The most recent attempt at treating alzheimers via amyloid is not going so well[1]. So, the causality implied by this article (poor sleep -> amyloid buildup -> alzheimers) isn't necessarily on the strongest theoretical footing.

[0]https://www.nature.com/articles/d41586-018-05719-4

[1]https://www.sciencemag.org/news/2020/11/biogen-s-alzheimer-s...

As an old guy with insomnia who freaks out seeing these headlines on the hacker news, I’d like to thank you sincerely. This shit is scary at my age.
Cold showers, warm milk and zero screen time right before bed. Thought of just mentioning it, dunno if it might help you in particular.
I do all that stuff, and more. Thank you, but it doesn’t help much. One one thing that helps is not having any screens or audio in bed and waking up at the same time every day. The latter is excruciating for me.
The world is full of advice about sleep, but very little of it is appropriate for everyone.
I was told that alternating cold and hot showers - a few cycles - help reset the nervous system. I tried it a few times and seems to be working, makes me feel relaxed and tired in a pleasant way. Simply taking cold showers before going to bed will make you feel invigorated, not very conducive to sleep.
Wait so shower for a few seconds cold, a few seconds heart, and repeat that cycle a few times before bed?
Yes. You can finish with hot. Make sure hot/cold water get all over your torso, chest and spine. You will feel really good afterwards even though the cold water isn't very pleasant. Alternatively, in the summer, take cold showers for invigoration, especially if you feel sleepy in the morning. It is unpleasant for the moment but it makes you feel great afterwards.
Is there a study showing that cold shower before bed helps sleep? Thanks
It was mentioned in Tim Ferris' book so I tried it at the time, considering I was living in a tropical country at the time, so the cold definitely helped get to sleep. I just checked once more and he mentions a Stanford University professor's quote on the same.
People will be tempted to infer causation here, but it's important to note that no evidence of causation is presented. It is most likely that some third condition causes both poor sleep and amyloid-b accumulation (since correlation usually doesn't indicate causation).
"It is most likely that ..."

I agree with your main point and was going to write something like this. But "most likely" is likely unjustified. It could be a 3rd factor that causes both, but its likelihood is unknown.

https://www.gwern.net/Causality

Correlation usually does not indicate causation. I.e. more than 50% of the time, correlative relationships in studies do not indicate causal ones. Taking that as a prior, and lacking any evidence to the contrary, it is indeed correct to say "it is most likely that ...".

... fair point! I stand corrected!
Causation is often treated as a binary outcome in the popular press, more recent attempts at adding nuance to that via statistics aren't much better. Hard to come up with solutions or alternatives but speaking personally I felt humbled at my own paltry understanding when reading this[1] reference.

[1] https://global.oup.com/academic/product/the-oxford-handbook-...

Yeah, but that's true with all long term nutrition and lifestyle studies, since it's impossible to test for causation with any degree of rigor (I don't even know what a long term double blind study would look like).

So, yes, correlation does not imply causation; it does still imply correlation. Even if a third variable, if you're getting poor sleep, you're more likely to have higher Amyloid-β build up

establishing causation is not impossible, just hard.
We take a preponderance of correlation as evidence, but we can't really provide rigorous proof. I mean, imagine what a double blind study to, say, 'prove' that smoking causes lung cancer would entail. The ethics of causing something we have reason to suspect is harmful to a population sample is ethically extremely problematic; hence, all we frequently have is correlative.

Even when it's something there isn't as big an ethical issue for it's usually not single blinded, let alone double. Diet, for instance; the groups know what they're eating. Did the differences happen because of the different diet, or because of something else (such as increased energy leading to more exercise, or the perception that they were eating 'healthy' lead to them actually becoming so, or picking up other healthy habits? Etc).

As I said, establishing causation -with any degree of rigor-, is basically impossible. Otherwise we're just left with "hey, a whole buncha correlative studies indicate this, so, maybe take it as true?"

Great, another thing insomniacs can lie awake worried about!
You joke, but my mum's mind has died from Alzheimer's and I'm literally having anxiety attacks induced from that leaving me to extremely poor sleep patterns.

Her father had Alzheimer's (undiagnosed AFAIK), and my mum had poor sleep patterns for sure (though not as bad as mine are, I think).

If there's truth in this then somewhat ironically, yes, there's a perpetuation there.

Sorry, to bring the town down.

You can get tested for genetic susceptibility to developing Alzheimer's. That might be worth a shot.

I also read that Keto diet has solid scientific evidence of preventing Alzheimer's fyi

No, I have bouts of onset insomnia too and I think at times it’s been exacerbated by worrying about my sleep quality due to reading news like this.

Really sorry to hear about your Mother.

You could try CBD oil, it helps me a lot to fall asleep. For the first time in years I sleep like a baby. I take around 10 drops sublingually. I know it's an overdose, but who cares, if it helps...
No joke, dude. I believe I'm going to think about this when I fail to fall asleep too.

What solves my sleep problems easily is a some weed but I don't always have where to get it since it's not fully legal at my location.

I hesitate to support HN's obsession with random Alzheimer's theories, but there's been a lot of research lately on the glymphatic system, vessels that clean waste protein out of the brain during sleep. This study is in line with that research.

The wikipedia page gives a good background on the glymphatic system: https://en.wikipedia.org/wiki/Glymphatic_system

https://science.sciencemag.org/content/370/6512/50.abstract https://science.sciencemag.org/content/342/6156/373

Based on this, if you are at risk for Alzheimers (your 23andme report shows this), then one of the most important things you can do today is to religiously track your sleep and make sure you get enough deep sleep daily.

In my anecdotal experience, if you don't get enough deep sleep for a sustained period of time, you start showing minor cognitive defects - e.g mixing up words, not being able to write long, irritability. Tracking sleep and 'catching up' makes all this go away.

This is especially important for people who are caffeine sensitive, but drink a lot of caffeine. You end up getting 5-6 hours of sleep nightly, and have this constantly mounting cumulative sleep deficit.

I understand your desire to help here but it's important to understand these kinds of attitudes can be counter-productive. My saving grace after several months of difficulty sleeping a decade ago was a book called "Say Goodnight to Insomnia" where they systematically break down why most of what you've written here is incorrect. Within a week of reading the book breaking away from many believing many of the things you've written above I was finally able to sleep well and have ever since.

From the description:

My insomnia program achieves its remarkable results because it is based on a simple yet powerful concept: insomnia can only be treated by addressing all the underlying causes. In most instances, the causes of insomnia are thoughts and behaviors (habits) that are learned and can be unlearned. Some examples include: - Attitudes and beliefs about sleep - Negative, stressful thoughts about insomnia - Feelings of loss of control over sleep - Inadequate exercise or exposure to sunlight - Going to bed too early or sleeping too late - Trying to control sleep rather than letting it occur naturally - Negative responses to stress - Lying awake in bed, frustrated and tense

"...Based on this, if you are at risk for Alzheimers (your 23andme report shows this), then one of the most important things you can do today is to religiously track your sleep and make sure you get enough deep sleep daily."

Getting enough deep sleep is probably good general advice anyway, but it's as-yet unclear if Alzheimer's or amyloid-β plaque buildup is caused by poor sleep; or if a third condition causes both poor sleep and amyloid-β buildup, in which case addressing the underlying cause is what will help, not religiously tracking sleep. Not enough information to say, yet.

But, yes, everyone get a good night's sleep!

It’s not clear that tracking sleep leads to improved sleep https://www.nytimes.com/2019/06/13/health/sleep-tracker-inso...
Here is my first thought when reading this kind of studies about sustained poor sleep:

Did anyone do a study on parents? Are all (where all is not 100% but around me pretty close to that) parents going to suffer from Alzheimer.

I am saying this because with few notable exceptions (like N=2) all my friends, including myself and my wife, slept poorly at least during the first year of their child and sometimes up until second year. I think this counts as sustained poor sleep.

So either I am living in a bubble and I should add this to the list of stressful things I feel (I read) I am not doing right as a parent, or nature decided at one point to select children of parents predisposed to alzheimer.