What Happens To Your Body And Brain If You Don't Get Sleep | The Human Body

Summary

In this educational talk, Professor Matthew Walker from UC Berkeley discusses the critical role of sleep for brain health. He explains that sleep deprivation hinders memory formation and increases beta-amyloid protein, linked to Alzheimer's disease. Walker also outlines how lack of sleep affects testosterone levels, the immune system, and raises the risk of various cancers and cardiovascular issues. He concludes by emphasizing that after 16 hours of wakefulness, cognitive and physiological decline begins, underscoring the necessity of eight hours of sleep to counteract the effects of wakefulness.

Takeaways

• 💤 Lack of sleep hinders the brain's ability to form new memories, as if the 'memory inbox' is closed.
• 🧠 Sleep deprivation leads to an increase in beta-amyloid, a toxic protein linked to Alzheimer's disease.
• 💧 Deep sleep activates the brain's 'sewage system' to clear out beta-amyloid, reducing the risk of dementia.
• 🚹 Reduced sleep in men can lower testosterone levels, effectively aging them by a decade in terms of virility.
• 🛡️ Sleep deprivation weakens the immune system, reducing the number of natural killer cells that fight cancer.
• 🚫 The World Health Organization classifies night shift work as a probable carcinogen due to its disruption of sleep patterns.
• 🩸 Insufficient sleep can elevate blood pressure and increase the risk of heart attacks and strokes.
• ⏰ Daylight saving time, which involves losing an hour of sleep, is associated with a 24% increase in heart attacks the next day.
• 🧠 After 16 hours of wakefulness, cognitive and physiological functions begin to decline.
• 🚗 Being awake for 19-20 hours impairs mental capacity to the level of legal intoxication while driving.

Q & A

What is the role of sleep in memory formation according to Matthew Walker?

Sleep is essential for the brain to make new memories. Without it, the brain's memory inbox shuts down, preventing the commitment of new experiences to memory.

How does a lack of sleep affect the development of beta-amyloid protein in the brain?

Sleep deprivation leads to an increased development of beta-amyloid, a toxic protein associated with Alzheimer's disease, because deep sleep is when the brain's sewage system removes this protein.

What are the consequences of sleep deprivation on the reproductive system?

Men who sleep only five to six hours a night have testosterone levels similar to someone 10 years older, indicating that lack of sleep can age one's virility by almost a decade.

How does sleep duration impact the immune system and cancer risk?

A single night of 4 to 5 hours of sleep can reduce the number of natural killer cells, critical for fighting cancer, by 70%. Short sleep duration is linked to an increased risk of developing various forms of cancer.

Why did the World Health Organization classify nighttime shift work as a probable carcinogen?

The World Health Organization classified nighttime shift work as a probable carcinogen due to the strong link between sleep disruption and an increased risk of cancer.

What impact does sleep have on the cardiovascular system?

During deep sleep, the body experiences a natural decrease in heart rate and blood pressure. Insufficient sleep can lead to higher blood pressure and a 200% increased risk of a fatal heart attack or stroke.

What is the effect of daylight saving time on heart attacks according to the script?

Losing one hour of sleep during daylight saving time in the spring is associated with a 24% increase in heart attacks the following day.

How long can a human typically stay awake before experiencing cognitive and physiological decline?

After about 16 hours of wakefulness, cognitive and physiological deterioration begins to occur.

What is the mental capacity impairment equivalent to after being awake for 19 or 20 hours?

After being awake for 19 or 20 hours, one's mental capacity is so impaired that it is equivalent to that of someone who is legally drunk.

How much sleep is recommended to repair the damage of wakefulness according to Matthew Walker?

About eight hours of sleep is needed to repair the damage caused by wakefulness.

Outlines

00:00

💤 The Impact of Sleep on Memory and Alzheimer's

Matthew Walker, a professor of neuroscience and psychology at UC Berkeley, explains that sleep is crucial for the brain's ability to form new memories, as a lack of sleep can shut down the brain's 'memory inbox'. He also discusses how insufficient sleep leads to an accumulation of beta-amyloid, a toxic protein linked to Alzheimer's disease. Walker highlights that deep sleep activates the brain's 'sewage system' to clear out this protein, and that chronic sleep deprivation increases the risk of dementia.

Keywords

💡Sleep deprivation

Sleep deprivation refers to the condition of not getting enough sleep, which can have serious consequences on cognitive function and overall health. In the video, it is mentioned that sleep deprivation can prevent the brain from making new memories and increase the risk of Alzheimer's disease by allowing the buildup of beta-amyloid protein. The script also discusses the broader health implications, such as the impact on the reproductive system, immune system, and cardiovascular health.

💡Memory inbox

The 'memory inbox' is a metaphor used in the video to describe the brain's capacity to store new memories. It suggests that without adequate sleep, this function is impaired, preventing the brain from effectively 'committing new experiences to memory,' akin to a full inbox that cannot accept new messages. This concept is crucial for understanding the video's message about the importance of sleep for memory consolidation.

💡Beta-amyloid

Beta-amyloid is a toxic protein associated with Alzheimer's disease. The video explains that a lack of sleep can lead to an increased development of beta-amyloid in the brain, as the brain's 'sewage system' is less effective during sleep deprivation, failing to wash away this protein effectively. This buildup is linked to a higher risk of dementia in later life.

💡Deep sleep

Deep sleep is a stage of the sleep cycle that plays a critical role in the body's restorative processes. The video emphasizes that during deep sleep, the brain's 'sewage system' is most active, helping to clear out harmful proteins like beta-amyloid. This stage is also when the cardiovascular system gets a 'reboot,' with heart rate and blood pressure dropping, which is essential for maintaining heart health.

💡Reproductive system

The reproductive system is affected by sleep deprivation, as highlighted in the video. It mentions that men who sleep only five to six hours a night have testosterone levels similar to those of someone 10 years older, indicating that lack of sleep can prematurely age the reproductive system and affect virility and wellness.

💡Immune system

The immune system's function is compromised by sleep deprivation, as the video explains that there is a 70% reduction in natural killer cells, which are critical for fighting cancer, after just one night of inadequate sleep. This link between sleep and immune function underscores the video's theme that sleep is essential for overall health and disease prevention.

💡Cancer

Cancer is mentioned in the video as a potential consequence of sleep deprivation. It is noted that short sleep duration can predict an increased risk for developing various forms of cancer, including bowel, prostate, and breast cancer. The World Health Organization's classification of nighttime shift work as a probable carcinogen further emphasizes the video's message on the importance of sleep for cancer prevention.

💡Cardiovascular system

The cardiovascular system is another area affected by sleep deprivation, as the video explains that deep sleep is when the body experiences a natural drop in heart rate and blood pressure, akin to receiving 'blood pressure medication.' Inadequate sleep can lead to increased blood pressure and a higher risk of heart attack or stroke, illustrating the video's point that sleep is crucial for cardiovascular health.

💡Daylight savings time

Daylight savings time is used in the video as an example of a global experiment that demonstrates the impact of sleep loss on health. The script mentions a 24% increase in heart attacks the day after the spring time change, when people lose an hour of sleep. This example highlights the immediate and tangible effects of sleep deprivation on public health.

💡Recycle rate

The 'recycle rate' mentioned in the video refers to the duration of wakefulness that a human can endure before cognitive and physiological decline sets in. The video states that after about 16 hours of being awake, mental and physical deterioration begins, emphasizing the need for sleep to 'repair the damage of wakefulness.' This concept is central to the video's argument that sleep is essential for maintaining brain function and overall health.

Highlights

Sleep is essential for the brain to create new memories.

Lack of sleep can prevent the brain from committing new experiences to memory.

Sleep deprivation leads to an increased development of beta amyloid, a toxic protein associated with Alzheimer's disease.

Deep sleep is crucial for the brain's 'sewage system' to wash away beta amyloid.

Sleep deprivation can age men's testosterone levels by a decade.

A single night of 4-5 hours of sleep can reduce anti-cancer immune cells by 70%.

Short sleep duration is linked to an increased risk of developing various forms of cancer.

The World Health Organization classifies nighttime shift work as a probable carcinogen due to sleep disruption.

Deep sleep is necessary for the cardiovascular system to reboot, reducing blood pressure.

Sleep deprivation can lead to a 200% increased risk of fatal heart attack or stroke.

Daylight savings time demonstrates the impact of lost sleep on heart attacks.

After 16 hours of wakefulness, cognitive and physiological deterioration begins.

Being awake for 19-20 hours impairs mental capacity to the level of legal intoxication.

Eight hours of sleep are needed to repair the damage of wakefulness.

Wakefulness is akin to low-level brain damage.

Transcripts

[Music]

My name is Matthew Walker I am a

professor of neuroscience and psychology

at the University of California Berkeley

and I am the author of the book why we

sleep we certainly know that a lack of

sleep will actually prevent your brain

from being able to initially make new

memories so it's almost as though

without sleep the memory inbox of the

brain shuts down and you can't commit

new experiences to memory so those new

incoming informational emails are just

bounced and you end up feeling as though

you're a music you can't essentially

make and create those new memories we

also know that a lack of sleep will lead

to an increased development of a toxic

protein in the brain that is called beta

amyloid and that is associated with

Alzheimer's disease because it is during

deep sleep at night when a sewage system

within the brain actually kicks into

high gear and it starts to wash away

this toxic protein beta amyloid so if

you're not getting enough sleep each and

every night more of that Alzheimer's

related protein will build up the more

protein that builds up the greater your

risk of going on to develop dementia in

later life what are the effects of sleep

deprivation on the body well there are

many different effects firstly we know

that sleep deprivation affects the

reproductive system we know that men who

are sleeping just five to six hours a

night have a level of testosterone which

is that of someone 10 years their senior

so a lack of sleep will age you by

almost a decade in terms of that aspect

of virility and wellness we also know

that a lack of sleep impacts your immune

system so after just one night of 4 to 5

hours of sleep there is a 70% reduction

in critical anti cancer fighting immune

cells called natural killer cells and

that's the reason that we know that

short sleep duration predicts your

risk for developing numerous forms of

cancer and that list currently includes

cancer of the bowel cancer of the

prostate as well as cancer of the breast

in fact the link between a lack of sleep

and cancer is now so strong that

recently the World Health Organization

decided to classify any form of

nighttime shift work as a probable

carcinogen so in other words jobs that

may induce cancer because of a

disruption of your sleep wake rhythms we

also know that a lack of sleep impacts

your cardiovascular system because it is

during deep sleep at night that you

receive this most wonderful form of

effectively blood pressure medication

your heart rate drops your blood

pressure goes down if you're not getting

sufficient sleep you're not getting that

reboot of the cardiovascular system so

your blood pressure rises you have if

you're getting six hours of sleep or

less a 200% increased risk of having a

fatal heart attack or a stroke in your

lifetime there is a global experiment

that is performed on 1.6 billion people

twice a year and it's called daylight

savings time and we know that in the

spring when we lose one hour of sleep we

see a subsequent 24% increase in heart

attacks the following day another

question perhaps is what is the recycle

rate of a human being how long can we

actually last without sleep before we

start to see declines in your brain

function or even impairments within your

body and the answer seems to be about 16

hours of wakefulness

once you get past 16 hours of being

awake that's when we start to see mental

deterioration and physiological

deterioration in the body we know that

after you've been awake for 19 or 20

hours your mental capacity is so

impaired that you would be as deficient

to someone who is legally drunk behind

the wheel of a car so if you were to ask

me what is the recycle rate of a human

being it does seem to be about 16

and we need about eight hours of sleep

to repair the damage of wakefulness

wakefulness essentially is low-level

brain damaged