I searched for "Why We Sleep flaws", which shows the #1 result by Alexey Guzey, and the #2 result someone else quoting Alexey Guzey. "Alexey is a writer and researcher studying the structures of science." This is who you quoted in your reply, above, as evidence that "Why We Sleep" has "riddled with scientific and factual errors". He's not an expert in sleep at all - nor neurobiology, for that matter. If there's a flaw here, it's using Google search results without understanding the qualify of the source.
https://newscience.org/team/
Compare that Google search to relying on the CDC, Harvard Medical School, and experts who wrote in the Journal of the American Medical Association (JAMA) a few months ago.
The CDC states that adults require "7 or more hours per night" of sleep, which contradicts the discussion you had with the OP.
https://www.cdc.gov/sleep/about_sleep/how_much_sleep.html
"Researchers found that individuals who slept fewer than five hours per night were twice as likely to develop dementia, and twice as likely to die, compared to those who slept six to eight hours per night."
https://www.health.harvard.edu/blog/sleep-well-and-reduce-your-risk-of-dementia-and-death-2021050322508
"Alzheimer disease (AD) ... Even during the more than 15-year preclinical (presymptomatic) stage of AD, decreased sleep quality and fragmented circadian rhythms are associated with AD pathology".
https://jamanetwork.com/journals/jamaneurology/article-abstract/2793873
Fair enough, I did do a shitty quick Google search to make that point. Criticism taken.
However, I stand by my position that pop science books by doctors and scientists are rarely seen as reputable scientific evidence of anything.
Also note, never once did I say anything about lack of sleep not being damaging. I don't know where you got that idea.
I said that the research that specifically quantifies amount of sleep is profoundly confounded. I also just stated above that some of the current thinking is that the minimum might be somewhere around 5 hours for people who don't have additional stresses on their systems.
Saying research is confounded is not the same as saying it's wrong or useless. It's just that many specific conclusions that are drawn from it are being revisited and looked at through a broader lens of the influence that other stressors have on sleep and overall health.
Basically, you can't ignore the "why" when it comes to length of sleep. If someone is chronically sleeping too little, why are they sleeping too little? And what impact is that having on their body?
I think it's fairly logical that a healthy, happy person who sleeps 5 hours a night, wakes rested, and has plenty of energy is going to have very different impact on their well being than a person who is stressed out of their mind, working long hours, doom scrolling before bed, drinking at night, and then waking exhausted and low key hung over.
What is very, very, VERY reasonable to draw from the research is that people who sleep at least 7-8 hours fare better. But we can't rule out the confounding factor that consistently sleeping those hours correlates with already being healthier.
7-8hrs of nightly sleep is an extremely good predictor of health, but is it causal? Unsure.
This is similar to how sooooo much of the research on the health benefits of moderate alcohol consumption were fundamentally confounded. The data was good, but the conclusions were terribly wrong. Why? Because it's all correlational and rarely was the *reason* for not drinking accounted for. This meant that the non-drinker group was often populated by ex-drinkers who had drinking related health problems, or other health problems that precluded drinking.
So did abstaining from alcohol *cause* worse mortality and morbidity rates? Obviously not. But that's how the data were interpreted, and then a pile of scientists went off and found plausible explanations for the mechanism, which further supported the assumptions.
Speaking of alcohol, that brings me to my next point. Just because I'm repeating that the sleep research is confounded does NOT mean I'm saying length of sleep isn't important. Nor do I think I've said anything of the sort.
Is alcohol damaging to health because of direct damage to the tissues or is it because of it severe impact on quality of sleep?
Lack of sleep correlates with all sorts of seriously negative lifestyle issues, and it's absolutely possible that the main mechanism is that they cause poor sleep and it's the lack of sleep that is causing the most damage. That's very possible, because we have no idea what sleep is or why we need it.
But the data just can't tell us that. Are people who have low stress, healthy lifestyles and no health issues all fine with 5 hours of sleep? Possibly. Or are there rare people who only need shorter amounts is sleep, and everyone else gets sick when they have less than 7.5 hours. I have no idea.
What I do reasonable know though, is that literally every single scientific study I've read on sleep has HEAVY hedging language in it where even the researchers indicate that their interpretations are limited and subject to change with more information.
This happens all the time. Presuppositions get reformulated when new data and new interpretations come about.
All I'm describing is what I've been taught is a very normal part of science. I don't see why there's an issue with anything I'm saying. Except yes, my shitty quality google search, I'll own that one.
But interpretations of data often change, especially correlation data, and *especially* health data. Hell, in the duration of my career many, many things we were taught as facts changed.
It's also common that there's a massive lag in the scientific discourse where old interpretations hang around a lot longer than they should. It's a known, major issue in healthcare in particular where doctors rarely update their foundational knowledge.
I for one contributed to my own misdiagnosis for a long time because I learned an outdated foundational fact about my own illness in med school.
I really don't think I'm saying anything unreasonable. I'm not claiming to have greater expertise than anyone, I'm claiming that no one has a level of expertise on this mysterious subject to draw many solid conclusions. I've certainly never seen any in the actual scientific literature, as I said that shit is always hedged to ends of the earth with "can't conclude" and "unsure" and "subject to change" and "requires further investigation."
I've studied under some of the so-called "world experts" in sleep medicine and literally walked out after paying thousands to see them because they're claiming very compelling conclusions that just aren't supported by the literature they're citing.
It's infuriating sometimes.
ETA: perhaps this will clarify my position. I worked in a specific area of sleep medicine where many practitioners horribly abused conclusions from confounded sleep science to justify extremely invasive and heinously expensive (70K) treatments for patients.
I was the second opinion doc offering a treatment that did the same thing, but for $500 and offering no explanation as to why it might work and no predictions either.
So I'm coming from a place of extreme mistrust of abuse of scientific interpretations.
Perhaps that's clears a few things up??
