by Dr. Joseph Mercola
November 10, 2018
from
Mercola Website
Spanish version
Story at-a-glance
Healthy sleep consists of several stages, each stage lasting five to
15 minutes, with a complete cycle taking between 90 and 120 minutes.
You cycle through each of these stages four to five times during the
night
Getting less than six hours of sleep in any given 24-hour period
will leave you cognitively impaired.
In 2013, drowsy drivers caused
72,000 car accidents in which 800 Americans were killed and 44,000
were injured
Polls show 63 percent of people do not get enough sleep to be
healthy, 69 percent struggle with frequent sleep problems and 22
percent are so sleepy during the day it affects their quality of
life
Sleep deprivation costs the U.S. economy $411 billion each year in
accidents and lost productivity, equivalent to 2.28 percent of the
gross domestic product
Recent research found people who got seven hours of sleep each night
had hearts showing signs of being 3.7 years older, based on
biological age, than their chronological age.
Those who got five
hours or less had the oldest biological heart age - 5.1 years older
than their chronological age
Sleep deprivation can have a number of health effects and
ramifications, ranging from mild to devastating.
The 2015 National
Geographic below video, "Science of Sleep," starts out with the story of
third mate Gregory Cousins, whose sleep deprivation led to one of
the greatest environmental catastrophes in history.
Cousins had slept only six hours in the past 48 hours when he ran
the
supertanker Exxon Valdez aground, causing the 11 million gallons
of crude oil to spill into
Prince Williams Sound, devastating 23
species of wildlife and nearly 13,000 miles of shoreline habitat.
Indeed, research shows getting less than six hours of sleep in any
given 24-hour period will slow your reaction time and leave you
cognitively impaired, unable to make rational decisions.
This is a
devastating combination, and accident statistics offer sobering
reminders of the seriousness of the situation.
In 2013 alone, drowsy drivers caused 72,000 car accidents in which
800 Americans were killed and 44,000 were injured. 1
This is more
than died from those texting and drunk drivers combined.
Sleep Deprivation Is a Recipe for Serious Accidents and Puts Lives
at Risk
According to the American Sleep Association, 2 nearly 40 percent of
people report unintentionally falling asleep during the day at least
once a month, and nearly 5 percent have nodded off while driving.
Most people skimp on sleep because they feel they have to "get
things done." However, the evidence clearly shows that what you end
up with is the complete opposite of productivity.
Sleep deprivation is actually costing the U.S. economy $411 billion
each year in accidents and lost productivity 3 - an amount equivalent
to 2.28 percent of the gross domestic product. An estimated 1.2
million working days are also lost.
In worst case scenarios such as the Valdez oil spill and the
space
shuttle Challenger accident, life is lost.
The latter is described
in the 1988 paper "Catastrophes, Sleep and Public Policy - Consensus
Report," published in the journal Sleep. 4
Other costly accidents
caused by sleep-deprived personnel include the
Three Mile Island
nuclear power plant accident and the
Mir space station
collision.
Polls show 63 percent of people do not get enough sleep to be
healthy, 69 percent struggle with frequent sleep problems and 22
percent are so sleepy during the day it affects their quality of
life.
Still, most say they will simply push through their sleepiness
in order to complete whatever it is that needs to be done.
But when construction workers, nurses, doctors, mechanics, pilots or
truck drivers, for example, go to work and "push through," it can
have lethal consequences for those around them.
Needless to say,
sleep deprivation itself is also hazardous to your health and is
perhaps one of the fastest ways to break down your immune function
and make yourself sick.
Research by Eve Van Cauter, director of the Sleep, Metabolism and
Health Center at the University of Chicago, also shows that sleeping
less than six hours a night dramatically increases your risk of
insulin resistance, which is at the core of most chronic diseases.
As noted in "Science of Sleep," research conducted in the 1980s
discovered that depriving mice of sleep for 17 days straight led to
certain death.
Two contributing causes were immune system breakdown
and blood poisoning.
Lack of Sleep Ages Your Heart
Studies have linked poor sleep with a variety of health problems,
including excessive aging of your heart.
People who got seven hours
of sleep each night had hearts showing signs of being 3.7 years
older, based on biological age, than their chronological age. 5
People who regularly slept either six or eight hours had hearts that
were on average 4.5 years older than their chronological age, while
those who got just five hours or less of sleep each night had the
oldest biological heart age - 5.1 years older than their
chronological age.
As noted by lead author Quanhe Yang, senior scientist in the
Division for Heart Disease and Stroke Prevention of the U.S. Centers
for Disease Control and Prevention: 6
"The difference between a person's estimated heart age and his or
her chronological age is 'excess heart age.' Higher excess heart age
indicates a higher risk of developing heart disease.
For example, if a 40-year-old man has a heart age of 44 years based
on his cardiovascular risk profile - the personal risk of having a
heart disease - then his excess heart age is 4 years.
In effect, his
heart is four years older than it should be, for a typical man his
age. The concept of heart age helps to simplify risk communication."
Of the 12,755 participants in this study,
-
13 percent slept just five
hours or less per night
-
24 percent got six hours
-
31 percent got
seven
-
26 percent slept for eight
-
about 5 percent got
nine or more hours of sleep each night
Considering the ideal sleep
time is between seven and nine hours, these statistics reveal at
least 37 percent of American adults aren't getting anywhere near
healthy amounts of sleep.
Sleep Quality Also Affects Blood Pressure and Heart Disease Risk
Other recent research 7 strengthens the link between sleep problems
and heart disease.
While this link has been previously noted, recent
research found that even if you sleep a healthy number of hours, the
quality of that sleep can have a significant impact on your risk for
high blood pressure and vascular inflammation associated with heart
disease.
Women who had mild sleep disturbance such as taking longer to fall
asleep or waking up one or more times during the night were,
"significantly more likely to have high blood pressure than those
who fell asleep quickly and slept soundly," Forbes reports.
8
According to the
researchers: 9
"Systolic blood pressure was associated directly with poor sleep
quality, and diastolic blood pressure was of borderline significance
with obstructive sleep apnea risk after adjusting for confounders.
Poor sleep quality was associated with endothelial nuclear factor
kappa B activation.
Insomnia and longer sleep onset latency were also associated with
endothelial nuclear factor kappa B activation…
These findings
provide direct evidence that common but frequently neglected sleep
disturbances such as poor sleep quality and insomnia are associated
with increased blood pressure and vascular inflammation even in the
absence of inadequate sleep duration in women."
Different Stages of Sleep and Their Importance
Sleep is not a single state.
Healthy sleep consists of several
stages, 10 each stage lasting five to 15 minutes, with a complete
cycle (light, deep and rapid eye movement or REM sleep) taking
between 90 and 120 minutes.
A full sleep cycle starts out in light sleep and progresses through
to deep sleep, then reverses back from deep to light sleep before
entering
REM.
You cycle through each of these stages four to five
times during the night, and this cycling is tremendously important,
from both a biological and psychological perspective.
-
Stages 1 and 2 (light sleep; non-REM)
During the initial stages
of sleep, biological processes in your body slow down but your brain
remains active as it begins the editing process where decisions are
made about which memories to store and which to discard.
-
Stages 3 and 4 (deep sleep; non-REM)
In these deeper sleep
stages you enter into a near coma-like state, during which
physiological cleansing and detoxification processes in the brain
11
take place.
Your brain cells actually shrink by about 60 percent
during this deep sleep phase. This creates more space in-between the
cells, giving your cerebrospinal fluid more space to flush out the
debris.
-
Stage 5 (REM)
During this last phase, you enter rapid eye
movement (REM) sleep, where dreaming takes place. In this phase,
your brain is as active as it is during wakefulness, but your body
is paralyzed, which prevents you from acting out your dreams.
The frightening experience of
sleep paralysis occurs when you awaken
during this phase and find your body unresponsive.
The "treatment"
for this disorder is knowledge.
As noted in "Science of Sleep," you
simply need to be educated about what's happening so that you can
calmly ride out the episode, which typically will not last more than
a few minutes.
All of these stages are important, and it's important to cycle
through them enough times each night - especially the deeper stages.
When stages 3 and 4 are missing or interrupted, your brain gets
clogged with debris associated with Alzheimer's disease and, indeed,
sleep deprivation is a risk factor for severe dementia.
Stages 1
through 4 are also what allow you to feel refreshed in the morning,
while stage 5 is important for memory.
Sleep Deprivation Takes a Toll on Mental Health
Forgoing REM sleep for extended periods of time may also lead to a
state where you actually start dreaming while you're awake,
resulting in delusions and wild hallucinations.
"Science of Sleep" (far above video)
features Dr. William Dement, a professor of psychiatry and
behavioral sciences at Stanford, who in 1963 oversaw a sleep
deprivation experiment by a young man named Randy Gardner.
"We were waiting to see if he would become psychotic," Dement says.
Gardner stayed awake for a record 264 hours - 63 hours longer than
Peter Tripp, a disc jockey who, in 1959, tried to break the world
record for sleeplessness.
Tripp stayed awake for 201 hours straight,
doing a continuous broadcast from Times Square.
For Tripp, hallucinations set in on Day Three. He saw spiders in his
shoes and became desperately paranoid, convinced people were trying
to poison him. He also became belligerent and abusive, and according
to one of the attending psychiatrists, "clearly psychotic."
Gardner, on the other hand, claims he was feeling all right up until
the eighth or ninth day, and didn't start having hallucinatory
experiences until the very end.
Once the experiment ended, after 11
days of wakefulness followed by 14 hours of sleep, a comprehensive
exam and mental health check was performed. Gardner was found to be
completely normal.
According to Dement, Gardner's experiment proved extended sleep loss
did not cause psychosis.
Tripp's experiment, on the other hand,
revealed that even though he was awake - walking around and talking
- his brainwaves showed he was asleep, and it was during the REM
cycles that he was most likely to hallucinate.
Essentially, he was
experiencing his nightmares in an awake state.
What's more, while Tripp had no signs of psychosis after the
experiment ended and he'd slept for 24 hours, many insisted his
personality had permanently changed for the worse.
He was no longer
as cheerful and easygoing as he'd been before, and those who knew
him best insist those eight days of sleep deprivation damaged his
psyche long-term.
In all likelihood, the effects of sleep deprivation will affect
different people in different ways, depending on a variety of
biological, environmental and perhaps even genetic factors.
The Influence of Genetics, Jet Lag and Stress Chemicals on Sleep
Sleep deprivation can be worsened by jet lag.
Also known as flight
fatigue, time zone change syndrome or
desynchronosis, jet lag occurs
when travel across time zones disrupts your internal body clock,
resulting in daytime sleepiness and lethargy, nighttime insomnia,
irritability, confusion and poor concentration. 12,13
Interestingly, researchers have found that people with a genetically
inherited sleep disorder called familial
advanced sleep phase
syndrome have a circadian body clock that runs about three hours
faster than normal.
According to "Science of Sleep," scientists are
trying to determine the protein associated with this gene, in the
hopes that it might be used to develop "jet lag drugs."
Whether or not such drugs will ever be realized, there are other,
more natural ways to minimize the effects of jet lag. For tips and
tricks, see "Can You Decrease Jet Lag With Exposure to Light?"
"Science of Sleep" also discusses research showing the role of
stress chemicals in waking.
Tests have revealed your body will begin
to release certain stress chemicals about an hour before your
intended wakeup hour, and that this occurs through mental
expectation or intention alone.
In other words, the stress chemicals
act as a sort of internal alarm clock, readying your body to wake up
at the time you mentally prepared yourself to get up.
General Sleep Guidelines
So, how much sleep do you need to optimize your mental and physical
health?
According to a scientific review of more than 300 studies
published between 2004 and 2014, a panel of experts came up with the
following recommendations.
Keep in mind that if you're sick, injured
or pregnant, you may need a bit more than normal.
Age Group |
Hours of sleep needed for
health |
Newborns (0 to 3 months) |
14 to 17
hours |
Infants (4 to 11 months) |
12 to 15
hours |
Toddlers (1 to 2 years) |
11 to 14
hours |
Preschoolers (3 to 5) |
10 to 13
hours |
School-age children (6 to 13) |
9 to 11 hours |
Teenagers (14 to 17) |
8 to 10 hours |
Adults (18 to 64) |
7 to 9 hours |
Seniors (65 and older) |
7 to 8 hours |
There's simply no doubt that sleep needs to be a priority in your
life if you intend to live a long and healthy life.
For many, this
means forgoing night-owl tendencies and getting to bed at a
reasonable time.
Sources and References
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