so, sleep is crucial to our lives. According to the National Sleep Foundation (NSF), sleep is essential for a person’s health and well-being: it not only helps our brains work properly, but also plays an important role in our physical health. Despite such predominant importance, we only know intuitively about sleep. So what more should we know about it?
Why do we fall asleep?
One of the first theories regarding sleep came from Alcmaeon, a Greek
writer. According to Alcamaeon, sleeping was a result of the flow cycle
of blood: when blood is carried away from under our skin to our core, we
would fall asleep until the direction of the flow is reversed, that is,
the blood flows back from our core to our skin. Then Aristotle claimed
sleep was tied closely to digestion: we would fall asleep until the act
of digestion was complete. Despite numerous theories about sleep
including those two, we now know that sleep is a result of several
chemical reactions and bodily functions in our body.
First of all, our internal body clock defines our daily bodily rhythm,
which is therefore responsible for putting us to sleep. Synced with
certain cues of the environment such as the amount of light, our
internal clock lets our body respond to the environment, mainly
chemically. In accordance with the surrounding environment, the clock
lets us secrete or reduce several chemicals in our brains, namely
adenosine, melatonin, acetylocholine, and cortisol, which are chemicals
that induce sleep. First with adenosine, the level of this chemical
continues to rise while we are awake, and puts us to sleep when a
certain amount of the chemical is accumulated. Once we are in sleep, the
reverse would happen: the body breaks down the compound, reducing the
concentration of adenosine in our body, and we would slowly wake up
again. When it gets dark, melatonin is released which makes us feel
drowsy therefore signals our body of the need to sleep. Also, the level
of acetylocholine in our hypothalamus, a portion of our brain that is
responsible for hormone production, drops naturally which also induces
us to sleep. And finally, cortisol, a steroid hormone that is closely
related to bone formation and inflammation, is released at last in
response to a low glucose level to wake our body up in the morning,
which is also called the “cortisol awakening response.”
Why should you sleep?
It is known that people can only live up to 11 days without sleeping:
this surely proves how crucial and important sleep is for human’s
well-being. The hours of sleep needed vary from people to people, in
regards to factors like age and lifestyle. Even so, it is recommended
that an average adult sleeps about 7 to 9 hours.
Sleeping
7 to 9 hours improves daily awareness and health. To begin with, simply
sleeping enough improves our learning capabilities and productivity,
while it also decreases our reaction time, making us less vulnerable to
our surroundings. As for the healing power of sleep, sleep not only
repairs our hearts and blood vessels but also stabilizes our immune
system for better defense and more efficient response against harmful
substances.
Perhaps therefore it may not be surprising to learn that sleeping less
than 7 hours each night in fact even reduces our life expectancy. It
jeopardizes our body into 12% higher risk of premature death, 45%
increase in risk of a heart attack, and a staggering 250% higher risk of
diabetes according to the journal, *Sleep*, a research conducted by the
University of Warwick. Also, lack of sleep may contribute to increase
in weight of 0.9kg in under a week. Moreover, it causes parts of our
brain to slow or shut down resulting in one or more of the several
effects: slower thought processes, lack of focus, blurred vision and
slurred speech.
Infogram:
· Back pain
· Headache
· 50% greater risk of diabetes
· 21% more likely to become obese
· Lack
of sleep was a factor in the many disasters in history: the Chernobyl
incident, Exxon Valdez oil spill, 1979 nuclear accident at Three Mile
Island, etc.
Steps to healthy sleeping
So how can we prevent all these things from happening to us? The answer
may seem like a cliché but the best solution is to sleep the
recommended hours. For a sufficient sleep of 7-9 hours nightly, it is
important to establish a healthy natural rhythm. You will be surprised
at how much the simple act of getting up in the morning when it is
bright, and going to sleep at night when it is dark will drastically
increase the quality of your sleep. Turning off distractions such as
cellphones and TVs before sleep, and taking a bath or drinking a hot cup
of milk or tea will also help you fall asleep more naturally. It will
heat up your body and slowly cool down which will help you feel relaxed
and drowsy. This may sound a bit ironic considering the fact that
keeping your body warm will help you fall asleep easier, but keeping the
room cold at around 18℃,will also have the same
effect. It is known that temperature around that range will decrease
core body temperature and induce sleepiness.
Simply increasing light exposure during the day such as avoiding the
use of sunglasses, spending more time outdoors and having more daylight
exposed to your room will also help. Or even better, just go to sleep
when you are truly tired. Moreover, believing you have slept well, even
if you have not, improves performance. Mind control will go a long way.
Box 1:
Some remaining interesting facts about sleep
The topic of sleep is very interesting. Here are some of the facts that make sleep such a fascinating topic:
· Humans are the only mammals that delay sleep by will.
· According to a recent study, people experience better sleep during the new moon and worse during a full moon.
· There
are actually many companies that promote napping as they believe it
will improve the productivity of their workers. Those companies include
*Google*, *Nike* and *British Airways*.
· An
experiment conducted in 1998 found that a bright light shone on the
backs of human knees may possibly contribute to resetting the brain’s
sleep-wake clock.
* * *
Sleep
- as marvelous and mysterious as it is - it is also crucial to our
mental health and well-being. Contrary to the frequently used phrase, it
seems like “sleep ain’t for the weak” after all. This month’s article
from the “Take a Break” section would like you to put your textbooks
down, tuck yourself in your bed, close your eyes and “Take a Break”.