top of page
Writer's pictureAniston Antony

Why do we sleep?



For a long time, we didn’t know what was happening during sleep. We were just thinking our brains were hitting the reset button and turning off for a while. But researches in the past decade have shown us that sleep might be the single most important human behavior.


Let’s understand what an alarm clock does- it actually stops the single most behavioral pattern we have! Our biological cycle of sleep. An average person spends 36% of their life in sleep. If you live up to the age of 90, that means 32 years of your life is spent in sleeping. This tells us that sleep at some level is important.


Why do we all try to abandon sleep in the first place? Why do we think sleep is not that important? That is mainly because we think we don’t do anything during our sleep, at least physically. We don’t eat, we don’t drink, we don’t think, we don’t do any of our important tasks, then why waste our precious time doing sleep, right? – A complete waste of time.


“Sleep is a criminal waste of time and a heritage from our cave days"-

Thomas Edison (Inventor of light bulbs)


As neuroscientists and psychologists dig deeper into the mystery of sleep, they discover, it is one of the fundamental needs we want to survive. But in our 21st century, we use Edison’s bulb to invade the dark and occupy the light and kill our sleep and treat it as our enemy.


What happens in our brain during our sleep?


Chemical reaction inside our brain:

During our waking hours, our neurotransmitters (neurons) keep our brain active particularly the cortex area primed for consciousness. But throughout the day, our neuron breaks down energy (ATP), the by-product builds up and activates sleep control neurons near the hypothalamus. This region acts as our master biological clock-SCN. SCN: The suprachiasmatic nucleus (SCN) is a bilateral structure located in the anterior part of the hypothalamus. The circadian rhythm is our body’s time to tell when to sleep. Light-sensitive cells from the retina sync up with the neuron to sync up with the earth's 24-hour cycle of day and night. These act as switches to when to feel sleepy or awake. As the world goes dark, the master switch tells our pineal gland to increase levels of the hormone melatonin. Thus, this sets in the fatigue, tiredness, body temperature lower and this heat loss is why most of us like to fall asleep with our feet sticking out of our blankets. This tells one thing to our body when it's dark, it's time to sleep. But unfortunately, we are so much used to our artificial light, our brain tricks us into thinking as it’s our natural sunlight thereby disturbing our sleep cycle.


What happens when we close our eyes?


Within the first 90 min of falling, we enter REM (Rapid Eye Movement). Throughout this cycle, our brain is as active as we are awake. Heart rate, breathing will be irregular, changes in brain temperature. This is also the time where we are having very vivid dreams. This is the reason why our body is essentially paralyzed at this time of sleep. Lack of muscle activity is a safety mechanism of our body to not act of our dreams and get injured. After the REM cycle, the body is in a much quieter stage, we now get into a much deeper sleep. It’s divided into 3 stages, N1, N2 and N3. While N3 is the deepest sleep stage of all. It is very difficult to get up from the N3 stage. Imagine you’re having 30 min sleep and someone wakes you up and you feel tired and exhausted. This is because you were into the deepest sleep and the chemical reaction happening in the brain is suddenly disrupted. N3 is also the stage where our muscles and our body start to heal and repair themselves.


Why do we sleep?


Restoration:

We restore, we rebuild, we replace during the night. A whole raft of genes gets turned on only during sleep and these genes are responsible for restoration and metabolism.


Energy Conservation:

If we compare an individual who slept during the night and an individual who didn’t sleep just laid down at that time. The guy who slept would have saved 110 calories, and that is not too much, just the calorie that is there in just one hot dog.


Brain processing and memory consolidation:

If you compare a person who is sleep-deprived and who slept, the ability of our brain to capture the thing in memory goes down for a sleep-deprived person.


Sleeping at night enhances our creativity, enables our ability to do complex problems and tasks much easier. The synaptic connection in our brain is strengthened during our sleep enabling us to strengthen our memory.


Causes of Sleep Deprivation


Society:

Most of us were getting 8-9 hours of sleep per night. But nowadays, it is 6-7 hours of sleep. Teenagers actually need 9 hrs, but most of them are getting only 5-6 hrs of sleep. They are not lazy; they are just sleep-deprived.


Night shift work:

When a night shift worker is going to sleep in the morning, his body clock tells him to wake up, this is the body’s time to wake up. This, conflict within the body causes serious long-term health problems.


“And millions of people suffer from jet lag every day. People often find it very hard to stay awake because their body is craving for sleep.”


Microsleep:

One of the responses our body does during this time of sleep deprivation is to engage in microsleep. This is an involuntary action of sleep and you eventually don’t have any control over it. Microsleep can be embarrassing in situations like waiting lines, jet lag, etc. But it can also be deadly. It is estimated at least 31% of drivers fall asleep when they drive at least once in a lifetime. In the US, 100,000 accidents happen due to microsleep causing tiredness, blurriness in vision and dizziness.


Tragic accident:

When investigators rolled deep into the cause of the Chernobyl Nuclear power plant accident and the Challenger Space shuttle accident: they discover a puzzling phenomenon. Since the worker's were working around the clock due to extended shifts, they fell prey to tiredness, loss of vigilance, microsleep- All these leading to poor judgment and eventually a disaster.


Stimulus:

If you have a tired brain, your conscious brain is craving to wake it up, microsleep is hitting you hard. In this time, you use a stimulus to keep your brain awake. So, drugs, smoke, caffeine, alcohol, all these stimuli you consume to keep your brain awake.


FACT: If you sleep around 5 hrs or less during the night, you have a 50% chance of becoming obese. Sleep loss generates the hunger hormone ghrelin gland, which indirectly seeks out carbohydrates by you eating.


Stress:

Tired people are extremely stressed up. This eventually causes loss of memory. Sustained stress associated with sleep loss is a major problem. This leads to suppressed immunity showing tired people have very little immunity. Increased level of stress throws glucose into your body in circulation which indirectly leads to type 2 diabetics. It may also lead to cardiovascular diseases due to increased blood pressure.


Lack of sleep:

Studies have shown that sleep-deprived (5-6 hrs of sleep) in men will affect the level of testosterone and has the level of someone that of 10 years senior to them. So, a lack of sleep will age you in terms of the reproductive system, virility and wellness. This is also seen in women in terms of their reproductive system. It is also found it lowers your level of the immune system. So after just one night of 4-5 hours of sleep, there is a 70% reduction in critical anti-cancer fighting immune cells called natural killer cells. So, that is why researchers have found short sleep increases your risk of developing different forms of cancer. This has caused much concern in WHO, that is why they made night shift work as a probable carcinogen.


Cardiovascular disease:

During your sleep, your blood pressure goes down, heart beat slows down. But if your are sleep-deprived (5.5 Hrs or less), then there is a 200% increase in the risk of a fatal heart attack or a stroke in your lifetime.


Studies also show that senile plaque develops in excess in brains for the people who are sleep deprived. This senile plaque is one of the reasons for Alzheimer’s disease. To know more about Alzheimer’s disease, click here.


FACT: Dolphins can’t nod off without drowning, so they only sleep with one half of their brain at a time, swimming along using the other half which is still awake.



How do I know if I am getting enough sleep?


If your facing:

  • If you need an alarm clock to wake you up every day

  • If you are taking a long time to wake up

  • If you need a lot of stimuli to keep you awake.

  • If you're looking tired and stressed up.

Then chances are your sleep-deprived. It is high time to listen to yourself.


Do we need 8 hours of sleep at night? – 8 hours is an average, as some people might need more, some might need less. If you oversleep, it has the same result of sleep deprivation.


What can you do?

  • Make your bedroom like a heaven to sleep. Dim off the lights as your going to sleep. Make the room as dark as you can when you’re setting down to sleep. Light increases your level of alertness and delays your sleep.

  • Turn off your mobile phone, turn off your computer, T.V, whatever excites your brain.

  • Try not to use any stimuli like caffeine, alcohol late in the day.

  • Light exposes in the morning is very good to set up your biological clock right.

  • Wind down an hour or half-hour before you go to sleep. Maybe meditate, listen to some relaxing music, having less conversation, be in silence, etc. can calm your brain down and prepare yourself for sleep.

Explore more about sleep through these books:

0 comments

댓글


bottom of page