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Sleep Flushes Toxins from the Brain

bbc.co.uk

11–20 of 98 posts

Re: Sleep Flushes Toxins from the Brain

#11
A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.

Re: Sleep Flushes Toxins from the Brain

#12
post #3

Can anyone with better knowledge of such things explain why this has to occur during sleep? Is there just too much going on during the day to dedicate physical and mental resources to this type of cleaning?

I have no better knowledge, just parsing the reports: The cleanup is more effective during sleep because the channels that transport waste from the brain expand 60% in volume, and the brain cells themselves shrink by a similar amount to make room.

I suppose that the brain cells can't shrink that much while retaining their full function.

Re: Sleep Flushes Toxins from the Brain

#13
post #5
post #4

Earlier quoted context omitted.

> [Dr Nedergaard] told the BBC: "This is purely speculation, but it looks like the brain is losing a lot of energy when pumping water across the brain and that is probably incompatible with processing information."

The question on everyone's mind now is, can you bypass that need?

I have a sneaking suspicion that would be like pumping oxygen directly into the blood and then trying to hold your breath - even though you technically don't need to breathe, millions of years of evolutionary tricks will make sure you do. Try telling your brain that it does not need to sleep after 72 hours just because you have cleared up the toxins

Re: Sleep Flushes Toxins from the Brain

#14

Science Now, the news service affiliated with the journal Science, has a write-up on this report, http://news.sciencemag.org/brain-behavior/2013/10/sleep-ulti... and that links to the abstract http://www.sciencemag.org/content/342/6156/373 of the published study itself.

I definitely prefer direct links to research publications over news outlets.

Re: Sleep Flushes Toxins from the Brain

#15

A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.

If you don't sleep for long enough (about 7 days), you'll start to have visual and auditory hallucinations and also delusional thinking. You'll also experience severely reduced effectiveness of just about every system in your body. You might not die if you don't sleep for a year (say), but you'll probably get permanent brain damage.

Re: Sleep Flushes Toxins from the Brain

#16

A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.

If you don't sleep for long enough (about 7 days), you'll start to have visual and auditory hallucinations and also delusional thinking. You'll also experience severely reduced effectiveness of just about every system in your body. You might not die if you don't sleep for a year (say), but you'll probably get permanent brain damage.

The point of science is to never fall back on claims like "you'll probably get permanent brain damage" unless it's known what brain damage you may get, along with bounds on a confidence interval. Otherwise we're just philosophizing.

Re: Sleep Flushes Toxins from the Brain

#17

A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.

The word "toxin" has become a signal for pseudoscientific medicine, so I also furrowed my brow at that. But the original use of the word is much more clear in context. From the abstract which tokenadult kindly linked to:

Thus, the restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.

Also, regarding the dangers of sleep deprivation, the first paragraph of the paper are relevant (http://www.sciencemag.org/content/342/6156/373.full):

Sleep deprivation reduces learning, impairs performance in cognitive tests, prolongs reaction time, and is a common cause of seizures (3, 4). In the most extreme case, continuous sleep deprivation kills rodents and flies within a period of days to weeks (5, 6). In humans, fatal familial or sporadic insomnia is a progressively worsening state of sleeplessness that leads to dementia and death within months or years (7).

Reference 7 is http://www.thelancet.com/journals/laneur/article/PIIS1474-44..., but I found the Wikipedia article more consumable for someone who is not up on medical research: http://en.wikipedia.org/wiki/Fatal_familial_insomnia

Re: Sleep Flushes Toxins from the Brain

#18

Science Now, the news service affiliated with the journal Science, has a write-up on this report, http://news.sciencemag.org/brain-behavior/2013/10/sleep-ulti... and that links to the abstract http://www.sciencemag.org/content/342/6156/373 of the published study itself.

Thank you for these links, I wish the BBC article included them. Here's the press release from the University of Rochester, where the study was conducted:

http://www.urmc.rochester.edu/news/story/index.cfm?id=3956

Re: Sleep Flushes Toxins from the Brain

#19

A "toxin" is something which is toxic to a system. But our knowledge of the brain is so primitive that we can't reasonably claim to know which chemicals are toxic at tiny, long-term dosage levels, unless it leads to death. There is no evidence that it's possible to die directly from sleep deprivation. Therefore this seems a dubious headline.

Rats die "within a matter of weeks" if they do not sleep: http://www.sciencedirect.com/science/article/pii/01664328950...

Re: Sleep Flushes Toxins from the Brain

#20

Earlier quoted context omitted.

If you don't sleep for long enough (about 7 days), you'll start to have visual and auditory hallucinations and also delusional thinking. You'll also experience severely reduced effectiveness of just about every system in your body. You might not die if you don't sleep for a year (say), but you'll probably get permanent brain damage.

The point of science is to never fall back on claims like "you'll probably get permanent brain damage" unless it's known what brain damage you may get, along with bounds on a confidence interval. Otherwise we're just philosophizing.

Science is slowly getting to those conclusions:

> Taken together, these changes in brain and body are further evidence that sleep deprivation is a chronic stressor and that the resulting allostatic load can contribute to cognitive problems, which can, in turn, further exacerbate pathways that lead to disease.

http://www.sciencedirect.com/science/article/pii/S0026049506...

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