What Science Says About the Power of Sleep
Introduction
Sleep is commonly perceived as a passive state,
a respite from the flurry of our waking lives. But that’s not the case, not in
this day and age, since modern science reveals the sleep story is something
else—the story of one of the body’s most evolved, restorative, and necessary
activities for physical health, mental clarity, and emotional well-being. From
boosting the immune system to enhancing learning and memory, sleep has a rich
and intriguing history of scientific study and an importance to our daily lives
that cannot be overstated.
In this wide-ranging article, we’ll discover
what science has learned about the biological importance of sleep, how it
affects every system in our body, what happens in our brain when we don’t get
enough of it, and how experts recommend we improve our sleep for a healthier
life.
Chapter 1: Sleep and the
Body’s Rhythms
What Happens When We Sleep?
Sleep is a complex and dynamic state with two main types:
• Sleep, Non-Rapid Eye Movement (NREM/Slow-wave
sleep)
•REM Sleep(period of day dreaming)
These stages repeat approximately every 90
minutes throughout the night.
Stage 1 (NREM): Light sleep during which the body begins to relax.
Stage 2 (NREM): Still deeper sleep; body temperature lowers, heart rate slows.
Stage 3 (NREM): Slow or delta wave sleep; essential for physical recovery.
REM sleep: when your eyes move quickly and you dream vividly, and is important for
brain health and emotional well-being.
Each phase serves a certain function in brain
and body care, and when done together, ensures full rest and recovery.
The Circadian Rhythm
The body runs on a 24h cycle called the
circadian rhythm, which is controlled by the suprachiasmatic nucleus (SCN) in
the brain. It controls sleep-wake cycles, hormone levels (such as melatonin),
body temperature and other bodily functions. Interferences with the
circadian rhythm (from night shifts, jet lag, or disrupted schedules) can significantly interfere with quality of sleep and overall health.
Chapter 2: Why Sleep Matters
Cognitive function and Brain
health
A memory-consolidative role of sleep has been demonstrated. In sleep, the brain consolidates information encoded during
the day, particularly into REM and deep NREM stages. This is believed to
strengthen long-term memory, boost learning, and encourage creative problem-solving.
Insufficient sleep has been associated with
diminished attention, slower processing speed, and reduced cognitive
flexibility. Even long-term deprivation can mimic symptoms typical of a
neurodegenerative disease, such as Alzheimer’s.
Immune Function
Studies indicate that sleep strengthens the immune
system. While the body sleeps deeply, it sends out even higher levels of
cytokines, a type of protein that can help fight infection and inflammation. Sleep
deprivation downregulates these defense mechanisms, making one more susceptible
to sickness.
As an example, research has indicated that
individuals who sleep fewer than 6 hours each night are substantially more
likely to become infected with the common cold when they are exposed to the
virus compared to those who receive 7 or more hours of sleep.
The Spectrum of Hormonal
Balance and Metabolism
Hormones Sleep modulates several hormones:
• Leptin and Ghrelin: Control appetite and satiety. Bad sleep raises ghrelin (the hunger
hormone) and lowers leptin (the “I’m full” hormone), increasing weight.
• Insulin: Sleep has an impact on insulin sensitivity. Lack of sleep impairs glucose
tolerance, and with it, we are more prone to Type 2 diabetes.
•Cortisol: A chronic lack of sleep increases levels of cortisol, the “stress hormone”
that modulates metabolism, immune function, and other essential processes.
Cardiovascular Health
Sleep and heart health are closely connected.
During deep sleep, heart rate and blood pressure are lowered, allowing the
cardiovascular system some respite. Chronic sleep deprivation may
cause hypertension, inflammation, and an increased risk of heart disease and stroke.
Chapter 3: On Dreaming, Sleep,
and Well-being
Sleep and Its Role in Emotion
Regulation
Sleep and the emotions are deeply entwined. REMS
in particular seems to play a role in emotional experience processing,
affective reactivity reduction, and mental stability preservation.
And then there are the chronic sleep problems
that are associated with:
• Depression
• Anxiety disorders
• Bipolar disorder
• You may have post-traumatic stress disorder (PTSD Halligan et al.
Indeed, insomnia is often one of the first signs
that mental illness is building.
The Vicious Cycle
Disrupted sleep can make mental health
conditions worse, and the conditions can also make sleep that much more
difficult, in a self-perpetuating loop. It is imperative to break this cycle
using support through therapy, medication, and better sleep hygiene.
Chapter 4: The peril of having
less or no sleep
Short-Term Effects
• Memory and decision-making issues
• Coordination and reaction time are diminished.
• Juxtapositioning and irritability • both recommendation..
• Accident due to lack of consistency (eg, while
driving asleep)
Long-Term Effects
• Higher risk of chronic illness (diabetes,
heart disease, and obesity)
• Weakened immune response
• Hormonal imbalances
• Cognitive decline and dementia risk
It’s also been found that getting a mere 5 or
fewer hours of sleep a night is linked to death earlier in life.
Chapter 5: How Much Sleep Do You Need?
The National Sleep Foundation provides the
following general guidelines:
|
Age Group |
Recommended Sleep Duration |
|
Newborns
(0–3 months) |
14–17
hours |
|
Infants
(4–11 months) |
12–15
hours |
|
Toddlers
(1–2 years) |
11–14
hours |
|
Preschoolers
(3–5) |
10–13
hours |
|
School-age
(6–13) |
9–11 hours |
|
Teenagers
(14–17) |
8–10 hours |
|
Adults
(18–64) |
7–9 hours |
|
Older
adults (65+) |
7–8 hours |
Keep in mind, quality matters as much as
quantity. Even eight hours of fragmented sleep may not be as restorative as six
hours of uninterrupted, deep sleep.
Chapter 6: Common Sleep
Problems
Insomnia
Insomnia is the most frequent sleep disorder and
is defined by difficulty falling asleep, maintaining sleep, or waking up too
early. It can be short-term (acute) or long-term (chronic) and is usually
caused by inflammation in your sinuses that affects the lining of your nose,
throat, and airways.
Sleep Apnea
A disorder characterized by breathing that
repeatedly stops and starts during sleep, sleep apnea can cause severe oxygen
deprivation, heart problems, and daytime fatigue. Often associated with snoring,
it is more common in people who are overweight.
Restless Leg Syndrome (RLS)
This neurological condition, which results in an
uncontrollable urge to move the legs, generally occurs at night. It can be an enormous sleep disruptor and can result in insomnia.
Narcolepsy
A rare condition characterized by persistent
excessive daytime sleepiness and very sudden muscle weakness (cataplexy) in
response to emotions.
If you believe you have a sleep disorder, please
consult with a healthcare professional or the sleep disorder center for more
details.
Chapter 7: Technology And The Modern Living
Blue Light and Screen Time
We also expose ourselves to blue light from our
electronics, which sabotages our melatonin levels and disrupts our circadian
rhythms. Justina Huddleston is a food writer living in New York City with her
husband and son. Late Night Screen Time May Delay Sleep and Decrease Its
Quality.
Stress and Overstimulation
Our always-on culture fuels chronic stress, a
leading impediment to restful sleep. Regular notifications, emails, and
anything else you can think of are keeping the nervous system in a state of
hyperarousal.
Chapter 8: Practical Advice for
Better Sleep
Stick to a Schedule
Enjoy the Good Night Light Show. Go to bed and
wake up at the same time every day — even on weekends. This aids in regulating
your internal clock and enhancing the quality of your sleep over time.
Create a Bedtime Routine
In the evening, do things that relax you—read, meditate,
or take a nice, warm bath. This will send a signal to your brain that it’s time
to calm down.
Environment Work Have You
Sleep That and Perfect
• Maintain the temperature of your bedroom at a cooler (60-67°F or 15-19°C).
• Replace your curtains with blackout curtains
to keep out light
• Restrict noise or use white noise machines
• Opt for a good mattress and pillow
Limit Stimulants and Alcohol
Don’t drink caffeine after mid-afternoon and moderate
alcohol, which can interfere with sleep cycles even if it helps you fall
asleep.
Move Your Body
Regular exercise leads to deeper and better
sleep. Try for at least 30 minutes of moderate exercise most days, but don’t
have any vigorous workouts close to bedtime.
Mind Your Diet
Heavy meals before bedtime can lead to
indigestion and troubled sleep. And foods high in tryptophan (from turkey, nuts,
and seeds, for example) could help naturally increase melatonin.
Chapter 9: When Does Your
Child Need Professional Help?
“It may be time to see a specialist if you have
tried sleep hygiene practices and are still struggling with sleep,” says
Michael Grandner, a sleep researcher at the University of Arizona College of
Medicine. Cognitive Behavioral Therapy for Insomnia (CBT-I) is a non-drug treatment
option that targets the root causes of sleep problems.
Other treatments may involve:
• Pharmaceuticals (with an open-minded approach) 5) How do they
heal?
• CPAP (continuous positive airway pressure) machines
for sleep apnea
• Diet and lifestyle advice
Conclusion: Sleep Isn’t an
Option, It’s Essential. Sleep isn’t optional at all.
Sleep isn’t a luxury,
but a basic biological need. Science– not to mention many of our own withering
bodies –– reveals that sleep has a profound relationship to our mental acuity,
emotional well-being, physical health, and even lifespan. Working after
a poor night's sleep is like driving with the handbrake on - you may
still be able to make progress, but it comes with a cost.
If boosting your mental performance, or your
immune system, or just feeling more energetic and balanced are goals for the new year, making
adequate sleep a health priority is one of the best things you can do. And keep
in mind: It’s time to stop glorifying sleepless nights and start honoring the remarkable force of sleep.
