The nation has spent the past year working, eating and, of course, sleeping in bed. In honour of National Bed Month, Hafsa Rahman explains why sleep is good for your health.
There is nothing quite like the feeling of slipping into a bed made with fresh, crisp sheets after an arduous day on Zoom. Absolutely divine.
Sleep is central to life itself. We spend approximately one third of our lives sleeping – or attempting to. We can live longer without food than sleep. All animals sleep (even the single-celled organism, the amoeba).
Sleep comprises of 90-minute cycles. Sleep cycles are made up of non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
NREM sleep is when muscle activity slows and body temperature decreases to reduce metabolic rate. In simple terms, these are the stages that lead to deep sleep.
REM sleep occurs after NREM sleep. Have you ever watched a person sleep and noticed their eyes are constantly moving beneath their lids? That is REM sleep.
In this stage, the body is paralysed and vivid dreams occur. You know – those wacky reels that leave you in a state of embarrassment or confusion once you wake up.
As a graduate neuroscientist, I could sit here and throw enough sleep science at you to put you to… to sleep. Instead, here are three reasons why sleep is great.
SLEEP IS VITAL FOR COGNITIVE FUNCTIONING
Sleep’s importance to cognition – mental activity – is complex, so I will keep this simple and focus on memory.
In the final two stages of NREM sleep, something called slow wave sleep occurs. This is when memories associated with fact-based information – the ‘what’ you know such as what you had for dinner last night – are consolidated. The memory is reactivated and your brain relives the information so you can remember it better.
When you dream about things relating to your day’s activities or the last thoughts you had before going to sleep, your brain is working away like an army of elves to make information ‘stable’ and become a memory. It is like athletes always say: ‘practice makes perfect’. Muscle memory is a thing and the brain works like a muscle.
The brain is also working away during REM sleep, but in this stage it is the memories associated with the ‘how’ we do something – like riding a bike – that are consolidated.
So sleep not only provides physical recuperation but helps to build mental strength.
SLEEP IS IMPORTANT FOR MENTAL HEALTH
Poor sleep, including from sleeping disorders such as sleep apnea, has been associated with many mental health issues such as depression. Sleep deprivation negatively affects mood and emotion. It has even been linked to increasing the risk of suicide.
About 90 per cent of patients with depression suffer from poor sleep quality, according to research.
Maintaining a regular sleep-wake cycle gives our minds and bodies the chance to reset and regulate to keep us healthy and ready for the challenges of the next day.
SLEEP IS VITAL FOR PHYSICAL HEALTH
Ever heard the saying, ‘healthy mind, healthy body’? Well, it is true. The sleep deficit can increase the risk of a string of health issues, from slower metabolism to type II diabetes to heart disease.
The slowing of our metabolism during NREM sleep is vital for restoring our metabolism ready for when it is fully active (during wake period). Metabolism is the chemical reactions that occur in our bodies such as converting food into energy. Researchers at UCLA found that less time spent in NREM can cause irreparable brain damage.
Alongside this, research has also shown that a shorter sleep cycle means that two important hormones which regulate glucose are not released. This can increase the likelihood of type II diabetes. For instance, a study in Sweden found that having fewer than five hours’ sleep was associated with higher incidences of diabetes.
There have also been links made between sleep and heart disease mortality. A study in Greece, which followed around 23,000 people over six years, found that the risk of mortality for those who regularly took siestas was 37 per cent lower. Dare we admit that the Europeans are actually doing something better than us?
Sleep is important – maybe more so than many of us thought.
So next time your friend says only one more drink at three in the morning at some club, know to say: “If it’s all the same to you, mate, I think I’d rather get some shut-eye.”
