For centuries our sleep patterns were dictated by the sun. Work was largely restricted to daylight hours and rest was the reserve of darkness. Then, with the invention of the lightbulb in the nineteenth century and the subsequent availability of cheap electric lighting, our relationship with sleep began a gradual but ultimately significant change.
Today, various facets of modern living have given rise to a reduction in both the time we spend sleeping and the quality of that sleep. Increasingly busy lives, constant distractions and the twenty-four hour availability brought about by the digital revolution, have all served to create a startling statistic: that is, across all developed nations, two in every three adults fail to obtain the average eight hours sleep per day recommended by the World Health Organisation.
So if you’re someone who struggles to switch off in the evening, someone who perpetually wakes unrefreshed or someone who needs the assistance of an alarm clock or a shot of caffeine to kickstart your day, then you’re by no means alone.
But that’s not to say that you should take comfort from being in the majority. Recent scientific studies have revealed that sleep deprivation affects everything from cognition to the function of cells, that regularly falling short of the magic eight hours can markedly increase the risk of Alzheimer’s, Cancer, Diabetes and Cardiovascular disease, and that not getting enough beauty sleep can even make us less attractive to potential partners.
In this article I will examine the most common causes of poor sleep in the twenty-first century, outline why sleep is integral to the maintenance of our mental and physical wellbeing, and detail some of the negative and irreversible effects that sleep deprivation has on the mind and body. Finally, I will establish what a healthy sleep routine looks like and suggest strategies we can all implement to improve the quality and quantity of our own slumber.
What’s Keeping Us Awake at Night?
Although the first electric light was developed by the British scientist Humphry Davy in the early 1800s, it is Thomas Edison’s patent of 1879 for a commercially viable lightbulb, that brought about a monumental shift in the way we perceive day and night. With the possibility of illumination twenty-four hours per day, seven days per week, came the potential for huge increases in productivity and profit. But the impact of this ‘progress’ on sleep – and subsequently on health – was far less favourable.
Edison’s scientific breakthrough extended the workday, making shift-work a realistic possibility and creating opportunities for entertainment and social activities beyond sundown. In doing so, it invited us to stay up later and for longer, to be alert when we might otherwise have been asleep, and to confuse our bodies’ circadian rhythms by remaining active (working, eating, etc) during biological night. The profound disruption this caused to our relationship with sleep has only recently begun to be realised and its impact has been furthered still by the dawn of the digital age.
Smartphones, computers and other devices have become integral to helping us manage our personal and professional lives, and few can deny that their benefits are plentiful. Instant access to our mail, contacts and calendars, payment options at our fingertips and the ability to manage both private and business affairs from virtually anywhere on earth has transformed the way we work and play, providing notable gains in efficiency and seemingly affording us the freedom of flexibility. However, the short-wavelength blue light emitted by such devices is twice as harmful to our sleep ambitions (when compared with yellow light from incandescent bulbs) and hence, that propensity to check our email, send a message or update our social media status before bedtime might be costing us much more than we think.
That said, our addiction to digital devices is not the only aspect of modernity to have had a negative influence on our sleep pattern. Changes to the thermal environment, jet-lag, use of stimulants like caffeine and sedatives such as alcohol, are all detrimental to our chances of securing regular restorative rest. And our busy multifaceted lives, together with the additional stress and uncertainty brought about by Covid 19, have only served to worsen the sleep loss epidemic that is plaguing industrialised nations.
It’s no surprise that disorders such as sleep apnea and insomnia are on the rise globally, but perhaps more worrying is the fact that many of us – without specific reason – are sleeping far less than we used to. In the UK, around two-fifths of adults report sleeping less than seven hours per night; the figure in the US and Japan is closer to two-thirds. But is this modern trend towards shorter sleep periods really something to concern ourselves with? Well, the simple answer is yes…
The Benefits of Sleep on Mind and Body
Eminent neuroscientist Matthew Walker, describes sleep as ‘…the Swiss Army Knife of health…’ stating that ‘…when sleep is deficient, there is sickness and disease. And when sleep is abundant, there is vitality and health.’ Much more than the ‘recharging of batteries’ we’re fed as children, sleep plays a significant role in the maintenance of physical and mental health, improves metabolic and immune function and enhances our powers of concentration and cognition. In short, sleep makes us fitter, healthier, happier and more productive. But how does it weave such magic?
The sleep process is triggered by the release of Melatonin at night-time, although the hormone itself has little influence in generating rest. Instead it serves as a signal, regulating our circadian rhythm sleep-wake cycle, by telling us ‘Hey, its getting dark… time for bed!’ Once we transition from wakefulness to rest, there are two main types of sleep between which we alternate during a typical ninety minute cycle. REM sleep (Rapid Eye Movement) – characterised by heightened brain activity and the stage in which vivid dreams normally occur, and NREM sleep (Non-rapid Eye Movement), during which the body carries out much of its regenerative work. NREM sleep can be further sub-divided into stages 1, 2, 3 and sometimes 4, with the numbers indicating not only the order in which they first occur in the cycle, but also the depth of sleep achieved in each stage. For adults, a healthy sleep period typically consists of five cycles with the proportion of REM / NREM sleep varying as the night progresses.
As we sleep, our bodies and brains undergo a series of changes that enable the restoration of energy levels, the regeneration of tissues and the recalibration of connections in our brains. Different functions are restored and repaired by different stages of the sleep cycle, and hence each is no more or less important than the other(s). The process itself is complex and its vast and wide-ranging benefits are only now beginning to be understood. But as the breadth of studies carried out in this field continues to grow, it is becoming increasingly apparent that all of our biological functions benefit from a good night’s sleep.
The list below – by no means exhaustive – details just some of the benefits we can expect to gain from regularly obtaining eight hours:-
- Improved memory function
- Enhanced problem-solving skills
- Enhanced creativity
- Better decision making
- Strengthened immune system
- Improved heart health
- Maintenance of healthy bodyweight
- Better mood
- Greater productivity
- Enhanced athletic performance
The Harmful Effects of Sleep Deprivation
Having established that sleep provides many benefits to our mental and physical health, I will now consider the negative impacts that lack of sleep and / or obtaining sleep of insufficient quality, has on the mind and body. As adults we’ve likely all experienced sleeplessness at some point or other, and as anyone who’s spent a night tossing and turning or endlessly staring at the ceiling will know, the effects – on the mind particularly – are pronounced. Irritability, low mood, difficulty thinking / concentrating, poor decision-making and an increased risk of accidents in the home and on the road, are just some of the effects we can expect from even a single night without sleep. But of greater concern – both on an individual and societal level – are the range and severity of impacts on health induced by sustained sleep deprivation. Chief amongst these are Alzheimer’s disease and Cancer.
The association between sleep loss and Alzheimer’s is not new but recent studies have shown that the link between the two is more significant than first thought. Deep sleep plays a vital role in flushing the metabolic waste product beta-amyloid from the brain, preventing the build-up synonymous with impaired cognitive function. In Alzheimer’s, these toxic proteins coalesce to form plaques, most notably in the very part of the brain responsible for generating deep NREM sleep. Hence, a vicious cycle ensues: insufficient sleep leads to greater amyloid deposits; greater amyloid deposits lead to further deterioration in sleep quality… whilst research is ongoing in this area, it’s clear that sustained insufficient or poor quality sleep will significantly increase the risk of developing Alzheimer’s disease in later life.
Along with Alzheimer’s, Cancer is perhaps the most high-profile disease in the western world, and subsequently an area of extensive research. Poor sleep quality is increasingly believed to be a risk factor in a range of cancers such as breast, colon and prostate, not just in terms of developing the disease, but also accelerating the growth of any malignant tumour that is present. Weakened immunity – in particular, a significant drop in the number of circulating ‘natural killer cells’, and a state of chronic inflammation triggered by the body’s sympathetic nervous system being sent into overdrive, are both synonymous with deprived sleep – even for a relatively short period, and both are contributory factors in the development and progression of some cancers. In fact, such is the strength of evidence in this field of study, the World Health Organisation has recently labelled the night shift as ‘probably carcinogenic’.
And as if the causal link with these most feared of diseases is not enough, other risks associated with long-term sleep deprivation include but are not limited to:-
- Increased risk of diabetes
- Reduced cognitive ability
- Anxiety and depression
- Weight gain and obesity
- Increased risk of cardiovascular diseases
- Weakened immunity
- Impaired coordination
- Premature ageing of skin
- Low sex drive
So What Does a Healthy Sleep Routine Look Like?
As with other aspects of health and wellbeing such as diet and exercise, the keys to a healthy sleep routine are scheduling and consistency. Depriving ourselves of rest during the week, only to binge on sleep at the weekend will not suffice. Even if on average we manage to secure the magic eight hours, the gains made on Saturday and Sunday will not erase the damage done Monday through Friday. On the other hand, setting a regular routine – regardless of what day of the week it is – by going to bed at the same time and sleeping for (approximately) the same duration, will allow both body and brain to establish and settle into a pattern that is conducive to high quality sleep.
Similarly, a careful scheduling of food and fluid intake, regular exercise (albeit not immediately before intended rest) and adequate exposure to natural light during the day, are all important in regulating our daily sleep pattern. And whilst it’s probably not what any of us want to hear, the removal of technology – or any other unnecessary distractions – from our sleep space, is absolutely essential if we’re to maintain a healthy sleep routine, reap the benefits of restorative rest and ward off the negative impacts on our minds and bodies.
Below are some useful tips to help you improve your sleep routine:-
- Set an alarm to remind you when to sleep not when to wake up. (It might sound strange but sleep scientists swear by it!)
- Create a distraction-free sleeping environment that is suitably dark and cool
- Avoid large meals and alcohol late at night
- Switch off screens at least an hour before bed… read a book instead!
- Limit your caffeine consumption to the morning / early afternoon
- Relax… take a warm bath, listen to soothing music, meditate