Will the real Randy Gardner please stand up?
In 1964, high school student Randy Gardner successfully stayed awake for 11 days and
24 minutes, setting the world record for the longest a human has gone without sleep.
Over the several days awake, Gardner experienced everything from mood changes, memory lapses,
random hallucinations to temporarily losing the ability to identify objects and recall
words.
But you don’t have to stay awake for multiple days to experience detriments from sleep,
as Neuroscientist Matthew Walker will tell you.
"I would like to start with testicles.
Men who sleep 5 hours a night, have significantly smaller testicles than those who sleep 7 or
more."
In his book “Why we Sleep,” Walker explains the ins and outs of just how bad too little
sleep is not only for your reproductive, cardiovascular, and immune health, but learning and cognition
as well.
Interestingly, lacking sleep even affects you socially.
-“...so we just published a study demonstrating that sleep loss will trigger viral loneliness."
As Walker is explaining here in this interview with Rhonda Patrick, this paper he authored
demonstrated that people are much less comfortable with people being close to them after they’ve
been sleep deprived.
They even put people in an MRI scanner and found that the brain is lighting up in a way
that makes you more suspicious of people and less able to understand their intentions.
Now, one of the things that was striking to me that Matthew Walker said was that you cannot
recover a sleep debt.
You can’t just “catch up on sleep” by sleeping for 12 hours on a Saturday after
3 nights of sleeping poorly.
So, if we only have one chance at sleep, then sleep quality or the efficiency of sleep must
be very important even if you’re getting the recommended 8 hours a night.
There are many things you can do to improve sleep quality and I’ve discussed this in
another video, but what I’ve been curious about lately is sleeping posture.
What is the best position to sleep in and, what is the best kind of pillow?
Or should we even use a pillow?
This question has bugged me for a while because I’ve tried all kinds of pillows including
this thing that’s supposed to keep your head from rolling to one side but I’ve never
been 100% satisfied.
“Oh, man.
You want a bad night?
Try sleeping on one of these.”
The first thing I thought might be worth looking at is how other primates sleep.
A quick google image search of “sleeping primates” - shows a lot of them sleeping
on their side.
As Charles Nunn explains, what the great apes have in common with humans is that they all
build some sort of comfortable nest or sleeping platform each night.
Humans have different bone structures from apes of course, but I thought it would still
be interesting to consider the position they sleep in most often.
This 2015 study, monitored the sleeping patterns of 5 Orangutans for two years.
They found that orangutans spent 3 times more of their sleeping time on their sides than
they did on their backs.
Now While digging into human research, I had trouble finding papers that specifically looked
at how sleep position affected sleep quality.
And, I couldn’t find any papers comparing sleep quality when people used a pillow versus
when they didn’t use a pillow.
But we can of course use a bit of logic and make some inferences based off the data that
we do have.
So I figure a sleep posture that promotes good sleep quality would have to (1) Prevent
snoring and (2) at least not impede the glymphatic system.
For now, let’s look at snoring.
What’s happening during snoring is that air flow is being partially blocked by tissues
in the airway, as evidenced by a… snoring sound.
I think more often than not, people would assume that snoring is mostly a nuisance to
one’s sleeping partner and the effect on sleep quality is not enough to cause alarm.
However, A study from 2003 looking at 1,144 school children separated the kids into either
“always,” “frequently,” “occasionally” and “never” snoring.
What they found was that in the kids, snoring “always” was significantly associated
with poor academic performance in mathematics, science , and spelling.
And snoring “frequently” was also significantly associated with poor academic performance
in mathematics and spelling .
Another study from 2001 found that children with lower academic performance in middle
school are more likely to have snored during early childhood.
Another study from 1994 showed that between age 4 and 7, “Daytime sleepiness, hyperactivity,
and restless sleep were all significantly more common in the habitual snorers than in
those who never snored.”
And Yet another study from 2005 titled “Snoring predicts hyperactivity four years later”
shows that “snoring and other symptoms of sleep-disordered breathing are strong risk
factors for future emergence or exacerbation of hyperactive behavior.”
I could go on with several more studies showing children who snore secrete less growth hormone,
how snoring is associated with headache and daytime sleepiness as well as high blood pressure,
heart attack and stroke but we can get into the full details in another video.
For now,
Here’s two recent nights from just the other week tracking my sleep with the app “snore
lab.”
Here’s a night where I snored a lot… and slept about seven hours, and here’s a night
where I slept less about 6 and a half hours barely snored at all - most of what the app
picked up was me rustling around and my air conditioner turning on and off.
As indicated by the orange frowny face, I distinctly remember being very groggy this
particular morning when I snored alot, but quite refreshed this morning when I didn't
snore that much.
One pretty clear example of snoring being disruptive to sleep quality is the fact that
it seems to wake me up - On the nights that I do snore, the recording will show that the
snoring sometimes wakes me up enough to rustle around or change positions.
This 2013 review on “positional therapy in position-dependent snoring” explains
that it’s often observed that snoring is usually worse when sleeping on the back and
better when sleeping on their side.
And, several papers have shown that sleep apnea gets worse when people sleep on their
backs.
During the American War of Independence and later during World War I , soldiers were advised
to wear their rucksacks on their backs while sleeping to keep them on their side and avoid
sleeping on their backs.
This would prevent snoring and making their position known to the enemy.
Papers from 1984 and 1996 found that people snore worse on their back, and this one
2003 study found that snorers snore less on their side
So far, it looks like sleeping on one’s side or at least avoiding sleeping on your
back would be good for sleep quality.
This study from 1983 found that ”Consistently, poor sleepers spent more time on their backs
with their heads straight.”
Now what about pillows?
There are several types of pillows and most of the ones advertised to improve sleep quality
aim to support the neck.
There is a natural curvature in the neck, a lordosis, and you can lose that and develop
something called flat neck syndrome.
This is developed presumably from looking down all the time, probably at your smart
phone or using a pillow that is too high.
But if we want to sleep on our sides, we shouldn’t need to worry about having the perfectly shaped
pillow and just get one that keeps your neck from bending too much while you sleep on your
side.
Moving on, to further evaluate sleep positions that promote good sleep quality, the position
should be good for glymphatic transport.
In the body, we have something called the lymphatic system that helps with each organ’s
problem of waste clearance - this network of vessels extends through the body and collects
cellular debris, proteins and other waste from the spaces between the cells so it can
be disposed of.
The brain however, does not have lymphatic vessels that it can use for waste clearance.
As Neuroscientist Jeff Iliff explains in his TED talk, this doesn’t make much sense considering
the adult brain uses about 25% of the body’s energy budget and generates a considerable
amount of metabolic waste.
“So how then does the brain solve its waste clearance problem?
The brain’s solution to the problem of waste clearance, it was really unexpected, it was
ingenious.”
“So the brain has this large pool of clean, clear fluid called cerebrospinal fluid.
We call it the CSF."
The CSF fills the space that surrounds the brain and wastes from inside their brain make
their way out to the CSF which gets dumped along with the waste into the blood.”
In the brain, there is a specialized network of plumbing that organizes and facilitates
the cleanup process.
You can see that in these videos...
The frame on your left shows what’s happening at the brain’s surface and the frame on
your right shows what’s happening down below the surface of the brain within the tissue
itself.
The blood vessels are labeled in red and the cerebrospinal fluid that’s surrounding the
brain in green.
“...and as it flushed down into the brain along the outsides of these vessels, it was
actually helping to clear away, to clean the waste from the spaces between the brain’s
cells.”
What’s interesting is that all this is happening when you’re asleep - the video on the left
shows how much of the cerebrospinal fluid is moving through the brain of a mouse while
its awake - barely anything.
But when the animal goes to sleep, the CSF rushes into the brain to rinse and clean it
out.
Alzheimer’s disease is an example of how important this sleeping brain cleanup procedure
is.
A hallmark of Alzheimer’s disease is the build up of a peptide called amyloid beta,
and the glymphatic system helps clear this stuff out of the brain.
The research on sleeping position affecting glymphatic transport is very limited, but
this 2015 study had rodents sleep on either their side, back or stomach and were monitored
via magnetic resonance imaging.
They found that “glymphatic transport was most efficient in the lateral position”
- on their side.
Dr. Maiken Nedergaard said: "It is interesting that the lateral sleep position is already
the most popular in humans and most animals — even in the wild — and it appears that
we have adapted the lateral sleep position to most efficiently clear our brain of the
metabolic waste products that built up while we are awake.”
One interesting thing about this study is that it specifically looked at clearance of
the Alzheimer’s protein Amyloid beta and found that removal of it was most efficient
in the side sleeping position.
Now This is just in rodents, but this study was looking at how sleep position could affect
neurodegenerative disease in humans.
This study strapped a small device with an accelerometer to the participant’s heads
to monitor what sleeping positions they were in and for how long.
They found that those people spending more than two hours sleeping on their back a night
was significantly more frequent in those with neurodegenerative disease.
Those with neurodegenerative disease spent nearly twice as much time on their backs while
sleeping - controls spent around 30% of their sleep on their backs, those with NDD spent
around 50% of their sleep on their backs.
The Hadza of Tanzania are often interesting to look at as their lifestyle is thought to
be similar to that of prehistoric humans.
I couldn’t find studies specifically on their sleeping position, but this brief video
talking about a study on the Hadza’s sleep patterns shows most of them sleeping ...on
their side.
So, the data is limited but it’s enough at least for me to want to try and sleep on
my side more.
However… the problem is that you can’t just say “OK time to sleep on my side because
Ulysses McGill said so.”
"How's my hair?"
People unconsciously change their sleeping position multiple times throughout the night.
One study found that over the course of 1 night, subjects changes positions as many
as 20 to 40 times per night.
So how can we get ourselves to stay on our sides, or at least bias ourselves to select
that position more often as we rustle around at night?
In 1984, the journal CHEST published a letter written by a patient’s wife.
She had cured her husband’s snoring problem by inserting a plastic ball into a pocket
sewn on the back of a T-shirt to prevent her husband from sleeping on his back.
In fact, there’s a type of therapy called “positional therapy” designed to keep
patients off of their back - all kinds of things from a backpack with a softball inside
to a ball in a sock on the back to a shark fin type thing to alarms that ring when you
roll on your back.
So ... what if pillows are making sleeping on our backs artificially too comfortable?
That is, let’s say you lay down to sleep, but you simply don’t use a pillow.
Laying on your back might become a little less comfortable now that your neck and head
aren’t cradled in a cushy comfortable cushion.
What’s going to be the more comfortable position?
Probably sleeping on your side because you can support your neck with your shoulder or
a pillow made out of your arm and hands.
Surprisingly, there was one paper that addresses this directly.
In this paper by Michael Tetley titled “Instinctive sleeping and resting postures: an anthropological
and zoological approach to treatment of low back and joint pain,” he argues that forest
dwellers, nomads and tribal peoples suffer from few muscoskeletal problems because they
sleep in a “natural” posture without a pillow at night.
According to Tetley, he has “organised over 14 expeditions all over the world to meet
native peoples and study their sleeping and resting postures.
They all adopted similar postures and exhibited few musculoskeletal problems.”
He says tribespeople often do not like having their photographs taken so he demonstrates
most of the postures himself.
What was interesting about this paper is that none of the positions he’s presented show
people sleeping on their backs.
So the data on this topic is limited, but based on what I did find, so far it seems
that the side position is the better position for cleaning out your brain and preventing
snoring from impeding your sleep, and ditching the pillow might be the way to get yourself
to spend more time in that side position.
That’s the idea anyway.
It’ll probably take some time to adjust to sleeping without a pillow and I’m not
saying this is realistic for everyone - if you don’t snore, and you wake up feeling
refreshed and are without back or neck pain in the morning there’s probably no need
to change your routine.
Also maybe you could figure out some other way to keep yourself on your side during the
night without ditching your pillow.
Actually I’ve been sleeping without a pillow for about a week now and I can’t say I’m
waking up drastically more refreshed, but I haven’t woken up with a stiff neck or
back yet - something that would usually happen every other day.
But I don’t really know if this way of sleeping is keeping me on my side like I was thinking,
so I’m planning to track a couple weeks of sleeping like this with a wearable device
and hopefully one of those baby monitor type see in the dark cameras.
I’m planning to post updates on my instagram every now and then, and at the end of the
experiment, I’ll post a thorough video on youtube letting you know how it all went.
And, If any of you would like to join me in the sleep experiment, I’ll post in the description
how I plan to do it.
Also, if any of you have done a sleep tracking experiment yourself in the past, please let
me know in the comments or on instagram what you used to track your sleep.
This video was sponsored by Kenhub - which is where most all the anatomical images used
in this video came from.
If you're a medicine, nursing, or physiotherapy student and want a way to drastically reduce
the frustration involved with packing ridiculous amounts of anatomy information into the thing
between your two auditory ossicles, you should definitely check out Kenhub.
With hundreds of engaging videos, interactive quizzes, complete articles and a full atlas
with stunning images, Kenhub is the best tool for learning anatomy I've come across and
it actually makes the process fun.
Check out Kenhub at kenhub.com