Do we really need sleep to cleanse the brain of toxins?

Great Debates
1

Many publications say that sleep cleanses the brain of metabolic by-products that the brain produces while being awake. While you’re asleep, your brain cells shrink and the fluid-space between your brain cells expands, and this allows the by-products such as tau, amyloid protiens, and adenosines to be flushed out.
A buildup of toxins in the brain is correlated with Alzheimer’s disease.

However, some animals like elephants and giraffes need very little sleep. Elephants usually sleep around 2 hours a night, and sometimes go several days without sleeping. When they do sleep, they don’t try make up for the sleep that was lost either. Also, most of their sleeps are done standing, and they don’t even get REM sleep. They only sleep laying down about 3 nights of a week, I read. Elephants also maintain excellent memory despite this lack of sleep.

**
SHORT SLEEPERS**
Most sources say that we humans need to sleep around 8 to 9 hours a day. However, some people can still function well off of less sleep.

In this article, short sleepers are considered to have “hypomania”
This article mentions that there are some short-sleepers with a gene called hDEC2, that reduces their need for sleep. http://www.nosleeplessnights.com/short-sleepers/
Then there’s Thai Ngoc, a man who hasn’t slept in decades, but is in pretty good health. https://en.wikipedia.org/wiki/Thái_Ngọc
So, why is it that a few people can function well with less sleep?
Could it be that they’re actually about to get Alzheimer’s, or maybe their brain is somehow more efficient?

2

A lot of questions in the OP, and they are about two topics we don’t understand well at all:

Sleep; where there are a number of hypotheses why we need it, most with some supporting data, but also with some conflicting observations. As you mentioned, for example, the amount of sleep different species require varies a lot and has little to no correlation with apparent brain complexity.

Alzheimer’s; of all neuropathologies, it’s perhaps the most mysterious. Yes we see tau proteins in the brain, but the causal relationship is not clear. Drugs to prevent the formation of these clumps have generally had little effect on the symptoms.

I’m skeptical about the man who hasn’t slept for decades. Insomnia is usually fatal within a couple of weeks for humans. Until he’s formally studied it’s much more likely a case of misreporting.

3

Sleep deprivation tests and extreme cases by individuals (studying themselves) show that after about 100 hours of being awake you start to hallucinate and also have continuous “micro sleeps” where parts of the brain will shut down into sleep modes even while you are seemingly awake, standing upright and eyes open. Memory is also severely effected and in some cases paranoia results.

Personal experiences:

It’s not conclusive but to me that seems to suggest that it plays several functions, both clearing waste that builds up and also plays some role in long term memory formation.

The more interesting question for me is , why do we dream?

4

I don’t know about “toxins” but sufficiently extended lack of sleep is fatal.

For example: Fatal Familial Insomnia

5

99% of the use of the word “toxins” is woo. Avoid all advice that incorporates it.

6

“toxins” is a garbage word created by those that don’t understand (or care to understand) science in any shape or form and rely on crap articles for their “scientific knowledge”

see also - climate change deniers, anti-vaxers…

7

I’m not sure that cause and effect is demonstrated in this case. FFI is a degernative disease that causes lack of sleep and also is leads to death, but its not clear (from this article at least) whether the lack of sleep is what leads to death, or if its is independently caused by the brain degeneration.

8

Agreed.

Which also means the OP should never use the word “toxins” if he/she expects to be taken seriously by anyone. Yes, there are metabolic byproducts that need to be removed from the brain and the body. Yes, we have systems to do that. Just never use the word “toxin” to describe what’s going on unless you want to be labeled an idiot.

And if you’re getting your “information” from people who use the word “toxins”, they’re idiots or charlatans or both. Which means you’re making yourself more ignorant by listening to them.

9

Dafuq? I’m in neurobiological research, and yes, we use the word toxin to describe any of a broad range of substances that are toxic to cells, from metabolic wastes to environmental pollutants. I agree the word is overused by crazies, but we (science/medicine) had it first and we’re keeping it.

10

Good point. Lemme be a little more specific.

If somebody like the OP can understand all the words in the article, “toxins” is almost certainly BS. If it reads like something written not only by PhDs but *for *PhDs, that’s a completely different situation.

11

Yes, I think most times you hear someone on-line use the word “toxins”, that person thinks the way to get rid of them is to pour coffee up your ass.

12

So if I say “Botulism is caused by a bacterial toxin” I’m speaking woo and BS?

13

Interestingly the actual Science article (paywall though) does not use the word toxin and for good reasons.

They instead use phrases like: “Proteins linked to neurodegenerative diseases”; “excess interstitial proteins”; and at most “toxic waste products” and “multiple potentially toxic CNS waste products.”

These are not “toxins” like Botulinum toxin (or Shiga toxin) nor “toxins” in the sense used by the woo-masters. I’ve not often read real science articles referring to metabolic products with potentially harmful impacts as “toxins” just because they are potentially of toxic impacts. Usually the term “toxin” refers in the science literature to proteins produced which seem to have the prime function of being toxic to other organisms, often by producing some immunologic reaction or by targeting receptors.

The increased CSF flow during sleep and its potential role in clearing out metabolic detritus is interesting but even if it is found to occur among all species beyond mice it would be a long step to attribute such as the purpose, or even a purpose, of sleep.

14

Toxins are the metabolic byproducts of the chemical reactions that cells perform. Sleep shrinks neurons to help wash these toxins away. Why is the use of the word toxins controversial? I thought that was agreed upon as a major motivator for sleep.

As to the fact that other species sleep less, I don’t know how relevant that is. Sure, using selective breeding I’m sure you could easily create a race of humans that only needed 2-4 hours of sleep a night. Just find the humans that already only need that much sleep, breed them, then breed the offspring that are most prone to this trait.

i’m sure there would be unforseen negative consequences, but that happens with probably almost every evolutionary trait.

But as it stands, humans need about 7-8 hours of sleep a night to function. A small minority have genetic alterations that allow them to get by fine with 4 hours a night without affecting energy, memory or mood. That’d be nice, sleeping from 1-5am and feeling refreshed. But for our current species, that is not realistic for the vast majority of us.

15

FFI is fatal, but I ‘think’ that is the only fatal form of insomnia. I’ve asked around on this board, and there are several people who are in their 60s and 70s who only sleep 10-20 hours a week who are still alive. So there are people who have lifelong severe insomnia who make it to their senior years.

it is my understanding that show insomnia causes death have two major criticisms.

  1. Those studies were done on rats and mice, who are not the same as humans.
  2. Those studies were done on animals that were capable of sleep and wanted to sleep, but were being kept awake by external factors (electric shocks, drugs, physical nudging, etc). This is not the same as someone who is able and willing to sleep, but whose body will not let them.

For point 2, I know when I have insomnia it is like my body makes better use of the small amount of sleep I do get. When I have severe insomnia and only sleep 4 hours a night, i am more rested than I am if I have natural sleep rhythms, but am only able to get 4 hours of sleep because I have to wake up extremely early.

Either way, according to charts like this, sleeping 3 hours a night is only associated with a 10% increase in mortality compared to sleeping 8 hours a night.

16

I agree.
I get occasional nights of insomnia when it feels like my body just failed to produce whatever it produces to make me fall asleep. I usually sleep well and I have a little mental trick that can usually put me out like a light. Even when I was being treated for anxiety and depression my normal sleep patterns were an anomaly.

But every now and then -once a year average, twice a year, tops - I just can’t sleep.
If I start taking sleep aids when this happens I’ll get a little sleep, 20 minutes for an OTC sleep aid, an hour with an Ambien. But I’ll feel like crap the next day

But if I just let myself not sleep, read and listen to music all night and don’t stress about it I feel absolutely fine the next day, sometimes even slightly more energized than usual

17

It’s another irony of life, that although it is indubitably true that the use of the term “toxins” should always be dealt with carefully, due to how many people who are simply fanatics use it; that the term “woo” has ALSO been compromised, in a sort of reverse manner.

That is, while it’s important NOT to blindly accept that anyone who says “toxins” knows whereof they speak, it is equally important NOT to blindly accept that anyone who points at people who say “toxins,” ( or some other tricky word) and says “woo” actually is enlightening you either. It is a common human challenge that it feels so good to think that you are on top of others in some way, by refusing to believe them, that many people will indulge in “woo” calling, JUST to experience the rush of endorphins that they get from self-worship.

This is, after all, a VERY tricky planet.

As to sleep, I just heard a more recent study of it mentioned on one of my favorite radio shows (which the Republicans hope to destroy, because someone told them it is "woo").  This relatively new study, measured performance on certain tests by subjects who were carefully arranged to have a variety of amounts of sleep.  The results were that although ALL of the subjects THOUGHT that they did well on the tests, the ones who were short changed on their sleep, did measurably poorly on the tests.  I don't recall the exact details, but it was fairly clear that the researchers set things up well enough for their results to be fairly reliable.

Anyway, they found that people didn’t always have trouble right away, when their sleep pattern was interfered with, but that over time, there was definite problems. Also, that they seemed to be able to recover (not suffer permanent damage) provided regular sleep was restored, at least intermittently.

Although I have seen MANY claims that lack of sleep results in "toxins" or toxic waste failing to be flushed away,  I have not yet seen even a single report indicating how sleep actually does this "flushing."

I have come to be convinced, that the main key to recognizing the validity of the use of terms such as “toxins” and “woo,” is found in whether or not the person promoting whichever, actually knows and describe the MECHANISM which accomplishes whatever it is they are telling you to believe. If they don’t know the mechanism, then whatever they are saying is just guesswork, however clever it may be, and however neatly it fits actual confirmed facts.

18

We can’t do studies on humans all the way to death, but we can follow symptoms for a few days and see escalating severe symptoms that match what we see in animals as far as we can compare behaviours and brainwaves. It does seem likely that lack of sleep, alone, would kill a human.

Exactly why sleep is fatal in animals is still an open question. In mammals there’s evidence to suggest that it’s your body’s temperature regulation shutting down that finally does you in, not the neurological symptoms.
Which of course just leads to more questions: why does it shut down, and how long could someone survive if you could externally maintain a core body temperature?

In terms of the distinction between being willing to sleep and being unable, I don’t think the distinction is so important here as apart from FFI, there aren’t really any conditions that will keep you awake for life-threatening amounts of time.
No matter what worries are on your mind, after about 3 days you will involuntarily have “micro sleeps”, and then eventually you’ll just pass out.
Insomnia is a bitch, but it’s as unlikely a cause of death (for someone without the FFI gene) as strangling yourself. And in fact for basically the same reason: you pass out.

19

It is “controversial” because, no, that is not what “toxins” in a biological context generally means (I’ve given my reputable cite, care to give yours?). Wiki actually has a good discussion of what toxins are and are not. Referring to metabolic byproducts that if not adequately cleared can have adverse impact as “toxins” is just an incorrect use of the term.

It is also controversial because of use of the word “toxin” by the woo-masters selling various products and treatments to “cleanse” and “detoxify” us of them.

Lastly, no the concept that sleep shrinks neurons to wash these metabolic by-products away is not generally agreed upon. This one article in Science in 2013 documenting this shrinkage with consequent increased clearance rate by the glymphatic system occurring in mice is suggestive and it is at this point an interesting novel concept. The hypothesis that the sleep disruptions seen early in Alzheimer Disease is not just an early sign of the pathology but possibly a contributor to the pathology as well is at this point just beginning to be explored. It may be true or may not be, way too soon to say.

20

Some publications are trying to imply that years of sleep loss is the cause of alzheimers. Some people are extremely busy all the time, and my only sleep 4 to 6 hours a night. When you do this, an excessive amounts of metabolic byproducts build up in the brain, and that damages your neurons.

Now, an elephant’s brain larger and less dense than a human’s so that means there is more space for the cerebral fluid to flow, and that makes it easier for those metabolic byproducts to be removed from the brain.
Just imagine if your brain much less dense with a lot cerebral fluid while at the same time you have the same level of intelligence. If that were possible you would be able to be smart and not need much sleep at the same time.