We all know that a good night’s sleep is important for us, but not many of us know why. In this blog post, we'll explain the links between sleep, stress and genetics. We’ll also give you some insight as to how you can gain some control over the uncontrollable, with a good night-time routine.
A lack of sleep appears to be an epidemic in today’s society. If you sat for a minute and thought about how you felt right at this second, you’d probably tell us you were tired. If pressed, we wonder if you’d be able to tell us why.
Today, we’re going to be looking at sleep. We’ll be looking at factors in our daily routines, stresses and strains of daily living, and how they impact our quality of sleep. We’ll also be looking at the factors we can’t control: our genetics (and how they influence our sleep patterns).
Sleep is an important part of not only surviving but thriving in our modern world. When we have a good night's sleep we feel refreshed, revitalised and ready to take on the world. In the same breath, after a night of tossing and turning, we feel slow, sluggish and just a little bit dim.
We’ve found that as we grow older, we tend to eschew the number of hours we need to sleep in one night in order to function at optimum capacity. This might be because we’re (probably) busy or because we feel that, as adults, we don’t need a set bedtime. At least not like we did when we were children.
How much sleep should you get in a night?
On average we should be getting between seven and nine hours of good quality sleep per night. The minimum number of hours an average adult can survive on is five hours per night. And, even then it’s recommended that you don’t make five hours the norm.
However, everyone is unique. We won’t all need nine hours in total - some people can function on as little as four hours (this is extremely rare). This boils down to genetics (we’ll get to that a bit later on in this article).
Why should you sleep for seven to nine hours per night?
Simply put, our brain (and body) uses our ‘downtime’ to heal.
There are four stages of sleep: 1, 2, 3 and REM (Rapid Eye Movement - not the band). The healing process generally takes place during the REM sleep cycle. If we look at the four sleep stages, they will look something like this:
Stage 1: the lightest stage of non-REM (NREM) sleep
Stage 1 is where our bodies start to relax and fall asleep. Our eyes are closed and our breathing becomes rhythmic. This takes us about seven minutes from closing our eyes to falling asleep. At this stage, we’re also easy to rouse. It takes us approximately 90 minutes to put us into stage 2.
While falling asleep, “people may experience hypnic jerks or abrupt muscle spasms and may even experience sensation of falling while drifting in and out of Stage 1,” according to Tuck, a free online sleep resource provider.
Stage 2: the first actual stage of NREM sleep
Stage 2 is the beginning of deep sleep. Our brain produces sudden increases in brain waves called the sleep spindles. Sleep spindles are when our brain gives us bursts of oscillatory activity which helps us fall into a deeper sleep. During this time, our heart rate decreases along with our body temperature.
Stage 3: deep NREM sleep
Stage 3 brings with it truly deep sleep - the drooling, snoring kind. During this stage, our brain produces slow delta waves. It’s here where our brain ‘reboots.’ It flushes out cellular detritus made by our brain cells during the day and stimulates growth. Sleepwalking and night terrors often occur during this time.
It’s during stage 3 and 4 that our immune system is boosted and we build energy for the following day.
Stage 4: REM sleep
The final stage of the sleep cycle is REM sleep. This is when we dream. Our eyes move rapidly, unlike stages 2 and 3, and we are more easily aroused during this time. However, waking during the REM cycle often leads to feelings of disorientation and grogginess.
Each REM cycle lasts between one hour and 90 minutes and - here is the critical part- we need between five and six REM cycles per night.
When we add up all the time needed for us to reach the desired stages in our sleep journey we need a minimum of six hours of sleep per night.
Stress and sleep
When we’re anxious or distressed about something that’s happening during our waking hours, the first thing to suffer is our quality of sleep. While it may seem obvious to some, it’s not always obvious to others. This is why sleep is an important element to consider as part of your stress management routine.
Think back to the night before an exam or a big interview.
Even though you willed yourself to sleep it might have been fitful, and you tossed and turned. This is because of our elevated cortisol levels.
In a study, in 2018, of approximately 2000 people across Great Britain, it was found that 48% of British Adults admitted to feeling stressed and anxious. And, 54% of them admitted to worrying about the effect that stress had on their health. This is because being distressed and anxious about something affects our ability to fall asleep and subsequently stay asleep. Thus ruining our quality of sleep. This in turn leads to more stress - it’s a vicious circle.
Being in a state of distress puts our body in a state of hyperarousal because of the amount of cortisol that our brain produces. This is a leftover from our more primitive existence when we needed the extra energy to escape predators.
Cortisol puts us in a heightened state because of the adrenaline our body produces, inhibiting our ability to sleep. Prolonged stress-induced insomnia leaves us feeling permanently fatigued.
But, there are things that you can do to calm down and relax after a long day - we’ll cover that later.
How genetics affect your sleep
The length of time you spend asleep can be linked directly to your genetics. A study has found that two regions of our DNA dictate how long we sleep for: PAX8 and PER3. They’ve also seen a connection between sleep disorders and genetics.
The first genetic region that’s most often associated with longer sleep times is PAX8, which regulates your thyroid hormone levels. Scientists have seen a direct link between people who suffer from hyperthyroidism (an overactive thyroid) and insomnia. On the other hand, people with inadequate thyroid function, or hypothyroidism, tend to sleep a lot.
Sleep scientists believe that this is why there’s a link between sleep and your metabolism. When you sleep longer, your body generally has a better glucose metabolism. This links back to the hyperthyroid sufferers - who often battle with unintentional weight loss.
The PER3 genetic region has been directly linked to SAD (Seasonal Affective Disorder) and depression. The PER3 region regulates the relationship between the sleep-wake cycle, and the relationship between mood and light. This means that being a morning person (or not) is essentially part of your DNA. Next time you’re late for an early morning appointment, you can use your genes as your excuse.
Essentially sleep patterns are influenced -or regulated- by genetic patterns and markers. But, we can’t forget the external factors, such as our ever-important environment.
Sleep hygiene - what is it (and how do you get it right)?
You may have heard the phrase ‘sleep hygiene’ bandied about recently, especially in conversations associated with the omnipresent blue glow from our smartphones. We’re here to tell you how to implement good sleep hygiene into your night-time routine which will hopefully give you a better quality night's sleep.
While there are certain bedtime factors that we can’t control, such as stress and genetics, there are some that we can.
The environment - our environment will absolutely have an impact on our quality of sleep. Everything from the amount of light that peaks through the curtains to the temperature of our bedroom will influence your quality of sleep.
Think about how the seasons affect our sleep. It can be hard to fall asleep in the stifling summer months. The optimum temperature your room should be, is between 15℃ to 20℃ for you to fall asleep comfortably and stay asleep throughout the night.
In order to implement and maintain good sleep hygiene habits, you can use these hints and tips:
Know how much sleep you need. While the average person needs between 7-9 hours we are sure you’ll find your happy medium.
Keep your bedroom for sleeping. Try not to bring work into the bedroom, as our brains begin to associate the environment with stress factors instead of rest.
Make sure your bedroom is calm and peaceful. Choosing a soothing colour scheme (such as light blue) can help make your bedroom more restful.
Limit the amount of light and noise disturbances. Don’t, for example, sleep with a night light or a TV on.
Limit your screen time at least two hours before going to bed. Although, ideally, you should turn your devices off at least three hours before bed (and they should stay OUT of your bedroom).
Go to bed at the same time every night.
If you practice these sleep hygiene tips, your quality of sleep should improve. And, with time (and commitment), they will form a nightly routine.
There will still be the occasional nights where we can’t seem to relax. We’re only human after all. On those evenings, it might be an idea to turn off your lights, light some candles and soak in a lavender scented bath (some people say that lavender promotes a good night's sleep). You could also enjoy a glass of warm milk, a cup of chamomile tea or a meditation session to calm the mind and ease your worries.
There’s not much left to say except, good night and sweet dreams.
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