Why We Sleep (and What Happens When We Don’t)

by Andrea Gardner

Why We Sleep (and What Happens When We Don’t)

If you don’t mind me asking, when did you last get a good night’s sleep? When I say ‘good’ I mean more than 7 hours, uninterrupted.

Insomnia is a modern plague and most of us get far less than the recommended amount of 8 hours every night.

Sleepless Nights

The World Health Organisation has even recently declared a sleep loss epidemic throughout industrialised nations.

Apart from the incessant demands of working, parenting, caring for a loved one, even socialising, many of us are helplessly attached to our digital devices, clocking up an average of 11 hours of daily screen time.

With too much to think about and too many demands on our energy, shut-eye gets pushed to the bottom of our list of priorities when it should be firmly at the top. Our modern 24/7 lifestyles, illuminated by artificial light, are pushing our natural rhythms to their limit. Since the beginning of the industrial age, humans have had to adjust their natural sleep times to fit around the working day. Whereas in pre-industrial agrarian cultures we would have slept from 9pm til dawn and enjoyed an afternoon nap of around thirty to sixty minutes, now we tend to just sleep at night, and that time window is getting shorter and shorter as we try to cram more into our day. Unless you live in a culture which still observes the siesta tradition, your afternoon nap is likely to have fallen by the wayside. Yet your body is still pre-conditioned to snooze mid-afternoon, a fact you’ll be well aware of if you’ve ever tried to sit through a boring presentation at 2pm!

The medical culture expects doctors, nurses and surgeons to work some of the longest hours in any profession, knowing they are making life or death decisions with insufficient sleep which severely impairs judgment.

Seeing medics, world leaders and CEOs boast about their ability to survive on 4 hours’ sleep a night perhaps leads us to believe that it’s a disposable commodity, something we can take or leave. Nothing could be further from the truth.

No Rest = Bad Days

Penguin has recently published ‘Why We Sleep’, an insightful and sometimes shocking book by Matthew Walker which explores the science behind the mystery of our nightly power-downs and why they’re so important for our health and wellbeing.

The book reveals that as well as demolishing our immune systems over time, routinely getting less than 6 or 7 hours’ sleep more than doubles our risk of cancer, reduces fertility and increases the risk of blocked arteries which can lead to cardiovascular disease, stroke and congestive heart failure. A person getting insufficient sleep for just one week will have their blood sugar levels disrupted so acutely, a blood test would diagnose them as being pre-diabetic. Add to this the hormone imbalance which a lack of sleep causes, making you crave more sugars and carbohydrates, and you can see why it’s almost impossible to lose weight when you’re sleep-deprived. Concentration and reaction times are one of the first casualties of not sleeping enough, leading to microsleeps and fatal injuries when driving or operating machinery.

Very little research has been conducted in the past about why we sleep, so you’d be forgiven for not knowing why it’s so important to every living being. Sleep laboratories are now fortunately giving researchers far more insight into what actually happens when we close our eyes at night. Here’s a brief summary:

First you will drop into a calm NREM sleep, a deep-wave state of repose that allows your brain to reflect on the day’s events and process them. If it helps, visualise memory packets being moved from a short-term storage facility to a more secure long-term storage site within the brain. You will eventually move into REM sleep, a much more mentally active hallucinatory state accompanied by the release of a chemical which paralyses the body, presumably to stop our dreams being acted out. During this dreaming phase, emotions, memories and experiences will be integrated, helping you to solve problems creatively and fine-tune a more accurate model of the world. Your brain will cycle alternately through both these cycles during a full night’s sleep, improving cognitive functioning such as balance, memory, learning and co-ordination when you wake up.

Your brain is not the only organ to benefit from this deep cleanse.

Shakespeare sums it up in Macbeth when he says that sleep is ‘the chief nourisher in life’s feast’.

A 2011 study that tracked half a million men and women of different age, race and ethnicity across 8 countries, resulted in the conclusion that shorter sleep (which raises blood pressure and calcification of the coronary arteries) was associated with a 45% increased risk of developing and/or dying from coronary heart disease within seven to twenty-five years of the start of the study. Midlife predictions are even more startling. Adults aged 45+ who sleep fewer than 6 hours a night are 200% more likely to have a heart attack or stroke in their lifetime, compared to those sleeping seven to eight hours a night.

Rest Well

During a good night’s sleep, rich in NREM phases, the brain sends a calming message to the body’s nervous system, reducing stress hormones, calming the heart and managing blood pressure. Ample sleep also replenishes the bacterial community known as the microbiome in your gut, rebalances the hormones necessary for reproduction, reduces inflammation and restocks the immune system so it can fight off infection and diseases.

With all this evidence to support the benefits of a good night’s sleep, you’re probably interested to know how you get one!

One of the fastest ways to improve your sleep is to go to bed and get up at the same time every day – sorry, that includes weekends. Invest in a sleep tracking device such as a Fitbit if you can to establish your baseline and understand how long you’re spending in each sleep phase. You can also sign up for our free 5-day mini-course to receive daily tips which will help you function at your best each day and sleep better for longer.

We hope you’ve enjoyed this post. Look out for more to come in the monthly sleep series. We’d love to hear about your own sleep patterns and insights – feel free to comment.

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