OCTOBER , 2022 | THE HEALTH

BY TONY PEREIRA

FOR many years , I thought sleep was something I could sacrifice to meet deadlines . In this day and age , where we never seem to be offline , being able to work with less than the recommended number of eight hours of sleep might be considered by some to be a badge of honor .

I have discovered that this is a dangerous path to take . I have been fortunate to work in Europe , North America , and Asia for well-established international organisations . I mostly survived on five to six hours of sleep a night .

Since I decided to step away from fulltime employment , I have taken courses on brain science . A common theme of every course has been the importance of sleep . Let me share with you what happens when we sleep and why it is important . 1 . During the day , toxins are created in the brain . There are a number of reasons for this . We have 87 billion cells in our brain . When we are stressed , for example , a chemical called cortisol is released by the gut and transmitted to the brain . The build-up of toxins will cause damage to the brain if it is not removed . Our brain has a self-cleaning mechanism called cerebrospinal fluid ( CSF for short ). When we sleep , and only when we sleep , CSF is released into the brain . CSF removes the toxins in the brain so that the brain can keep working at optimum capacity . If we do not get enough sleep , then the toxins may not be removed . If toxins remain in the brain , a plaque called amyloid beta is formed around the brain cells . Scientists have determined that one of the causes of Alzheimer ’ s disease is the build-up of amyloid beta in the brain . “ As we get older , the ability to clear toxins is diminished ,” says Professor Michael Chee , a director of the Center for Cognitive Neuroscience at Duke-NUS university . That is why it is important to get enough sleep throughout , especially when we are in our thirties and forties .

2 . There are two types of sleep -REM or Rapid Eye Movement and Non-REM . When we first fall asleep , we are in non-REM sleep . During this phase , the brain goes through its maintenance processes -i . e CSF is released to clear the toxins ; unused brain cells are pruned ( i . e . removed from the brain ). When we get to REM sleep new connections that were made during the day are transmitted from the hippocampus ( a seahorse-shaped structure in the brain ) to other parts of the brain . So , if we are a student for example , whatever we learned during the day is stored in the hippocampus . When we sleep , or more specifically , when we are in REM sleep , the new information which was stored in the hippocampus is distributed to different parts of the brain for future

use . If we do not get to that stage of sleep , then potentially we will forget what we learned very quickly . It is important therefore that we get sufficient REM sleep so that apart from the maintenance process , which is important , the brain can also develop these new connections .

A typical sleep cycle is as set out in the chart above . The chart shows how important it is to get the full eight hours of sleep that is typically recommended . The large bulk of REM sleep occurs between the sixth and eight hours of a sleep cycle . If we have less than six hours of sleep daily , we are not getting the full amount of REM sleep . The important processes that take place only in REM sleep ( committing new learnings to memory for example ) will be sacrificed .

3 . Research has also shown that lack of sleep can lead to other medical conditions such as weakening of our immune system , increasing the blood sugar level in our system , and blocking of coronary arteries which can lead to a heart attack . In Greece in the year 2000 , the government decided to abolish nap time during the day . Subsequent studies found an almost 40 per cent increase in the risk of dying from cardiovascular disease ( for men , the increase was 60 per cent ).

We know , therefore , that sleep is

Source : Drunk or just tired ? How sleep deprivation affects your cognition . February 2021 edition of On Psychology and Neuroscience important . But why do we feel sleepy and is there anything we can do when we feel this way ? Sleep is caused by a chemical called adenosine . When we wake up after a good night ’ s sleep , our adenosine level is low . As the day progresses , the adenosine levels increase . As it increases , we progressively get tired and start to feel sleepy .

Typically , the adenosine level is at its peak at around 11pm . Having a short nap during the day can help our energy levels increase . The late Margaret Thatcher , the former Prime Minister of Britain was a big believer in power naps .

She mentioned in many interviews that she was able to keep alert because she took power naps during the day to reenergise her mind and body . Of course , there are stimulants that one can take to stay awake even if our adenosine level is high . The most common of course is caffeine .

Caffeine , however , does not reduce our adenosine level . It simply blocks adenosine from reaching the receptors in our brain . The adenosine will continue to build and once the effect of the caffeine ( or whatever other stimulant that we take ) wears off , we will literally feel knocked out . In a normal situation , it takes eight hours for the brain to clear adenosine from the system .

Here are some simple but effective tips for getting a good night ’ s sleep . 1 . Make sure your bedding is comfortable . Make sure the room temperature is also comfortable . The body takes in more oxygen when the temperature is lower .

2 . Avoid gadgets that give out blue / white light . The brain produces a hormone called melatonin which is the sleep hormone . However , if we are looking at gadgets before sleeping , the brain will believe it is still daylight and hence will not release melatonin to help with the sleep cycle .

3 . Avoid drinking too much liquid before sleeping . If you drink too much water just before sleeping it is likely your sleep will be disrupted as you will need to empty your bladder .

4 . Follow as best you can , a fixed timing for sleep . Our body follows a circadian rhythm . The more you follow this rhythm , the more effective your sleep pattern . Circadian rhythms are physical , mental , and behavioral changes that follow a 24-hour cycle . When we travel long distances , our circadian rhythm is disrupted and hence we take a day or two to acclimatise to the time clock of the new location that we travel to .

5 . Plan your naps ( if you take them ). Naps reduce the level of adenosine in the brain . Make sure that you time these well so that you can still get your eight hours of sleep each night .

Why do we feel sleepy when on a flight ?

Have you ever felt sleepy when on a long flight ? This has nothing to do with adenosine . When we are on a flight , the cabin pressure is reduced to simulate being at an elevation of 6,000 to 8,000 feet .

At this level , oxygen levels are lower . The blood absorbs less oxygen and hence we feel sleepy , and we lack mental alertness . So don ’ t leave important tasks for that long flight that you may have to take for work . – The Health

Tony Pereira is an Independent Consultant and Founder of SuperTrouper365