I’ve always had a wonderful relationship with my bed. I’ve never had trouble sleeping nor do I particularly fancy a life without 8 hours sleep. Admittedly, for a lot of busy people, that’s hard to do. I already feel the dedicated mothers of this world scorning me, and rightly so! I don’t know what it’s like to raise kids, yet anyway. Right, let’s get going with the reasons why we need sleep…
Sleep statistics for the UK and Western World are quite alarming.
In Japan, it’s even worse, where men reportedly attain only an average of 5 hours 59 minutes/night.
It’s certainly no laughing matter. Have a look at what it’s costing the UK economy:
It’s clear the economic impact sleep-deficiency has, and the mental health implications have been in the limelight for years. Why do we continue to disobey? Is it because we’re too busy, feel we’re getting enough sleep as-is, or you struggle with an undiagnosed sleep disorder? Do we not understand the reasons why we need sleep?
Therefore, I’m going to hopefully present you with some excellent information I got from Matthew Walker’s book, Why We Sleep. He’s a neuroscientist that provides a wonderful account on the necessities of sleep, in layman’s terms. Hopefully, this article will do him partial justice.
Although it’s not difficult for me to adhere to the WHO (World Health Organisations) and National Sleep Foundations guidelines of 8 hours/night, SO many individuals fail to attain this. That’s not me bragging by the way – I’m a teenager stuck in a 25-year-old man’s body. I think I’d die if I didn’t get 8 hours sleep/night, seriously…
But its quite a serious matter, because sleeping for less than 6 hours/night consistently, greatly increases the risk of cancer, cardiovascular disease, stroke and generally decreased immunity. Not to mention the psychological impacts of depression, anxiety and suicidal tendencies.
Sleep is a universal elixir and a massive positive combatant to all of the above physiological and psychological traumas and illnesses.
Sleeps fiercest rivals
What are some of the aspects of everyday life, processes and compounds that prevent good quality sleep? Let’s start with jetlag. Bear with me here as I describe to you our internal body clock…
All of us have a 24-hour body clock embedded in our brain called the circadian rhythm, controlled by the suprachiasmatic nucleus, sitting in the middle of the brain. These small nuclei secret the ‘vampire’ hormone, melatonin. It tells your body that sleep needs to begin and the concentration will build until you fall asleep, thereafter, the levels decrease in your body until dawn.
You know, we’re no different to plants in this regard, which experience heliotropism, which is where a plant tracks the suns trajectory through the sky. As such, plants open their flowers during daylight but shrivel up at nighttime, meaning, they know when its day and night because they have their own internal rhythmic times. Humans are the same.
Therefore, darkness is humans biggest cue to sleep. So, what happens when you traverse timezones? You’re moving geographical locations quicker than your body can keep up, thinking its nighttime during the day. From personal experience, travelling back to the UK after giving in Singapore for 6 months meant I was waking up, completely alert, at 3 am for the first few days.
Your body will adapt, biologically, to the sunlight signals, but the suprachiasmatic nucleus can only catchup 1 hour/day. That’s why it’ll take roughly a week to resume regular sleeping patterns after long-haul flights, as I did from Singapore to the UK.
Caffeine – is a psychoactive stimulant that’s the second most traded commodity on the planet after oil. Caffeine suppresses adenosine, which is another sleep hormone. This sleep hormone is correlated to ‘sleep pressure’, which is a hormone that builds up the moment you wake up, growing in concentration throughout the day, eventually reaching it’s peak in the evening when you feel extra sleepy and desperately need your bed.
As such, if you consume a lot of caffeine in the evening, with the primary source being coffee, then you’re preventing the buildup of adenosine and that’s why you don’t feel tired at nighttime. Furthermore, the effects of caffeine peak 30-minutes after consumption and has a half-life of 5-7 hours, which is disastrous for your sleep. It takes 5-7 hours for the concentration to decrease by half as your body metabolizes it. That’s a lot of fo caffeine lingering around for someone due some shuteye!
Some rare individuals have abnormally high concentrations of an enzyme in their liver: cytochrome, which digests caffeine. These superhumans can drink coffee to their heart’s content, although the breakdown efficiency will decrease with age. I genuinely think my mum has such enzymes. She will drink multiple cups of coffee up until 9 PM EVERY NIGHT and sleep like a baby. She literally falls asleep as soon as her head hits the pillow, I’m not joking…
Sleep as we age
This part of Matthew Walker’s book fascinated me. Sleep does change as we age but some misconceptions are surrounding this, notably, that old people need less sleep. This isn’t the case at all and I’ll dive into the details on this shortly. You see, we need ample amounts of sleep at any age. Home sapiens (humans) are the only species on the planet to deliberately starve themselves of sleep. Let that sink in. Every species ever recorded in existence sleeps; from the moment life began. If Mother Nature saw it as an inconvenience, I’m sure she’d have weeded it out millions of years ago. I guess, we humans haven’t fully grasped the power of this adaptation. Sleep has massive advantages key to our survival.
This still rings true as we age, but lets first look at sleep before you’re even born. Yes, an unborn baby is sleeping in the REM-state. Only in the last trimester will the baby experience partial wakefulness in the womb.
And before I talk about the holistic benefits of this, lets address REM sleep. This stands for rapid eye movement, and the reason its coined as such is that your eyes are moving rapidly underneath your closed eyelids while you’re sleeping! Which sounds a little creepy, but this stage is massively important for memory retention. It’s the stage where there is heightened brain activity and the process of dreaming occurs.
In other words, when your eyes are moving rapidly, you’re dreaming in the REM cycle.
You’ll notice in the graph below that our brain cycles through this phase every single night, alternating with the other type: NREM, or, non-rapid eye movement. And yes, you guessed it, your eyes are calm in this phase, and your brainwave activity is a lot lower.
The x-axis refers to 8-hour sleep duration, with the y-axis showing the stages of sleep. As you can see from the graph, NREM has 4 stages, with stages 3 & 4 being deep NREM sleep. We do not dream in these 2 stages, with our brains miraculously being able to transition between REM & NREM to make up for the very finite amount of memories we can store in our brains.
It’s so crucial that we’re able to get 8 hours of sleep so that our brain can cycle through REM and NREM continuously. We can’t have one without the other, and we first enter NREM sleep. Now, you might be asking, “Donald, what if I skip out on 2 hours of sleep each day? 6 hours of sleep is fine, right?” So, this is what happens when you skip on just 2 hours of sleep:
Okay, 2 hours less from a healthy 8-hour sleep is a 25% reduction in total hours. But, it’s as much as a 60-90% reduction in total REM sleep, which drastically decreases cognitive functioning and memory retention. Heck, some parts of the brain are 30% more active when you’re sleeping:
A brain that’s awake but a body that’s asleep – pretty crazy, right!
So yeah, even 1-2 hours less of sleep each night, compounded over many years, could have untold health implications. REM sleep invokes creativity, and many a great invention in the past has been conjured up after sleeping on it. One of the best examples is Dimitry Mendelev in 1869 when he dreamed of the organisation of elements in the Periodic Table for the first time! Thomas Edison, who had a whopping 1,000+ patents by age 21, was a big advocate of the daytime nap. The rest is history…
Then you transition from a baby to a child, and you’ll sleep earlier because your circadian rhythm is programmed to do so. A lot of parents may find it rather easy to put their kids to bed at 7-8 pm. You may have to carry them up to bed as they’ve fallen as sleep on the couch. I know some parents wish they were that lucky. I feel for you…
Then its quite strange how the circadian rhythm takes a massive jump into the teenage years. It seems like overnight you transition from an 8 PM sleeper to pulling an allnighter, effortlessly. Teenagers circadian rhythms are genetically programmed to sleep at 11 pm -12 midnight. This rings so true to me and I’m sure all of you, as when I was a teenager, no matter what I did, I couldn’t fall asleep before 11 pm. The crazy thing is I’m 25 years of age and sleep at around 9:30 PM! I know, pretty sad right. But I couldn’t fathom that at 18 years old, nor would my body allow it.
Because of my early bedtime, I’m a morning lark but as a teenager, I certainly wasn’t. I don’t think any teenager is a ‘morning person’. Think about it, if you’re sleeping for 11 PM, 8-hours of sleep would mean getting up at 7 AM, which is perfectly reasonable. You’re getting a healthy amount of sleep and NOT oversleeping. Your body is still growing so 9-10 hours of sleep isn’t crazy, rising at 8-9 AM.
Based on my recent past with my parents, who were dumbfounded at my inability to rise before 7 AM, just know that it can’t be helped. It’s Mother Natures methods and not that teenagers are lazy. Simply know that all teenagers are genetically programmed to go to bed later and rise later – nothing to worry for all you parents out there. It’ll get better, I promise.
Let’s look at the elderlies sleep tendencies. Contrary to many beliefs, the elderly need just as much sleep as early and midlife adults. Now, do they generally attain less sleep?
That’s perhaps due to medication, or trips to the bathroom as your bladder weakens with age, or aches & pains. Your sleep efficiency decreases, which is around 70% of 65+ years of age compared to 95% for teenagers, who are literally comatose.
How we match up
Every single animal on this planet sleeps; whether you’re a mollusc, starfish or a bug. Even unicellular and multicellular organisms living for 24 hours. Admittedly, some of these creatures are simply too small to measure their brainwave activity, but you can decipher based on decreased responsiveness and no movement. And I’d say we have it better than most animals due to the comforts of our warm homes, shielded from adverse weather and predators.
For example, let’s compare humans to our closest living relative, the chimpanzee. They, like the bulk of primates, spend about 9% of their total sleep time in the REM phase, in comparison to 25% for humans. And there is a fascinating reason for this…
There is a sensation called atonia, in which our muscle tone weakens and even goes completely limp during REM sleep. This certainly isn’t good when you’re arboreal! If you’re sleeping in a tree and your body decides to go completely limp, you’re easy pickings for the hungry jaguar lurking below…
Simply because of the way we sleep and the environment in which we sleep, it allows us to maximise our time in the REM-phase, which as I mentioned prior, is responsible for memory rejuvenation. It allows us to conjure up ideas freely and solutions for problems the next day. Chimpanzees cannot do this anywhere near as well as humans can when you think of our engineering and scientific discoveries…
Its almost as if our quality of sleep is better, as interestingly, primates sleep for 10-15 hours compared to 8 for humans. We sleep a lot less than primates, but we dream a lot more and accomplish a lot more.
And this isn’t restricted to primates. We have one of the highest, if not the highest levels of REM sleep among the animal kingdom. There seems to be a strong correlation with the REM duration and the danger level of the environment. If you experience high-consequence hazards routinely in your natural environment, that species has very little to no REM sleep. For instance, amphibians, fish, and cetaceans (like killer whales) do not experience REM sleep because as we mentioned earlier, REM sleep induces involuntary paralysis! Meaning, these animals would stop swimming, something these animals would never do in their lifetime. They must continually swim to breathe and survive.
And this is astounding: seals can live on both land and ocean, where they will attain REM sleep on land but NOT whilst sleeping in the water! Whilst in the water, seals, like all solely marine-dwelling species, are unihemispheric. This means they sleep with one half of the brain active whilst the other rests, then it switches.
This whiteboard animation video I made summarises our comparison with animals quite nicely :
Reasons why we need sleep
Sleep protects newly acquired information and makes room for more memories and learning the following day; sleep is consolidation time. Even a 20-minute nap at lunchtime is great for consolidation. But modernised society has rid most of us of this healthy habit many would perceive as being ‘lazy’.
Nevertheless, it’s quite natural to nap and many animals do it. Early Homo sapiens and our ancestor would have done so. We’re fighting against our genetic traits nowadays, sleeping a monophasic and not biphasic pattern.
As such, is it surprising that where siesta still exists in Ikaria island, Greece, or Italy, men that practice biphasic sleep is 4 times as likely to reach their 90s than Americans?
Personally, I think not.
Also, sleep improves athletic performance. Usain Bolt is famous for taking naps before races and even before Olympic gold. If you have less than 6 hours of sleep then your time to physical exhaustion is 10-30% less and aerobic exhaustion time is reached faster.
I’ve already discussed how sleep is great for memory retention, but it’s also a necessity for memory deletion:
“Forgetting is the price we pay for remembering” – Matthew Walker
We can’t remember everything. That’s impossible. Our brain performs something called targeted memory reactivation – where you are selecting memories to retain as you sleep overnight. You may not realize it but you have that power – you can choose to remember something and sleep enhances the retention. Simultaneously, you can choose to forget. Because forgetting is important. Time heals all wounds, thanks to sleep.
We sleep to forget bad memories of addiction, loss, divorces etc. Like a computer cache, you’re deleting stored memories you just don’t need. Why would you want to remember the bad times! Grow from them, learn from them, then delete the vivid hurtful memories and make way for good ones!
Less sleep makes you fat.
Yup. Sorry to be blunt about it, but it’s true. Have you ever tried to pull an allnighter for your university dissertation or your boss is breathing down your neck for that report? Maybe you thought those carbohydrates would give you an energy boost? Well, a lack of sleep increases the secretion of the hunger hormone (ghrelin) that gives you the insatiable need to consume unnecessary amounts of food.
Think about it, your body is under siege from a lack of sleep, which is greatly depleting your energy levels. We all know food boosts your energy, heck, we need it to survive. Primal instincts kick in and your brain is telling you to go and top-up the vitality meter. Your body is sticking to the hunter-gatherer roots, telling you to increase your fat storage in times of hardship. When the reality is you should have done your homework a week ago!
But the crazy thing is, your body is taking a battering from an allnighter. Too many of them could cause irreversible damage. And I’m going to dispel a sleep myth for you. You CANNOT reclaim lost hours of sleep. In other words, you cannot sleep off what you’ve already lost. If you slept for a couple of hours or didn’t sleep at all, sleeping for 9-10 hours the following day won’t save you. It’s not just the ghrelin you have to worry about; there are a host of health consequences.
The illustration below summarises many of the key consequences sleep deprivation has:
Furthermore, it’s important to realise when you’re sleep-deficient. Be true to yourself when answering the following:
- Do you feel sleepy/drowsy at 10-11 am? Like, you could genuinely fall asleep if you went to read the newspaper in the work toilet cubicle.
- Can you wake up naturally at the same time every morning without an alarm clock? Is it a great struggle to get out of bed?
- Can you function well without caffeine before noon? Don’t get me wrong, most of us love a morning cup of coffee, but is it essential for you to perform well each day?
If you answer ‘yes’ to all of the above, chances are you aren’t getting enough sleep.
Besides, here is the list Matthew Walker complied, which I synthesized and applied to my life:
- Same sleep schedule every day
- Exercise is great but try not to do it 2-3 hours before bed
- Avoid caffeine and nicotine: caffeine takes 8 hours to wear off from a cup of coffee
- Avoid alcohol before bed
- Skip big meals at night, same with drinks
- Avoid medications that interfere with sleep – see if the prescription can be changed or taken earlier in the day
- Don’t nap after 3 pm
- Relax before bed for 1 hour
- A hot bath/shower before bed, as getting out the shower helps drop core body temperature
- Dark, cool, noise-free bedroom
- Have the right sunlight exposure during the day
- If you’ve been in bed for 25 minutes and can’t sleep, do a relaxing activity light reading with a dim light
Sleeping pills should be the last resort, seriously. 10 million Americans use sleeping pills/month. Diazepam used to be used but is clearly a sedative, targeting the same receptors of the brain as alcohol. A lot of people with insomnia rebound as sleeping pills are classified as physically addictive drugs – a cruel irony.
I love ASMR (autonomous sensory meridian response) for those pleasant tingles and induced numbness from listening to the soft tones of peoples voices. It is by no means sexual arousal – far from it. If you want to know more about how it can help you sleep, click here.
Click here if you wish to see my list of resources for this article on reasons why we need sleep.