We all know we can’t survive without air, water and food. But there’s a fourth basic element that is just as crucial to our survival – something we produce ourselves: sleep. You probably didn’t know, sleep ranks third place on the survival scale: without oxygen or air, we’ll die after around five minutes. If we don’t drink any water, dehydration will be the cause of our death after a maximum of four to five days. We can live for up to 60 days without food until the lack of nutrients in our bodies becomes so depleted that our organs cease to function. Interestingly it is staying awake for between 10 and 14 days that can also be deadly!*
Here are 10 things you didn’t know about sleep:
1. Sleep consists of five phases
It begins with two light sleep phases, where our consciousness hasn’t fully shut down, preparing us for the next stage. Then there are two phases of deep sleep, this is the most vital stage of sleep which is most beneficial. Deep sleep is then followed by the REM sleep phase (the phase in which we dream). To be fully rested by the morning, an average of five sleep phases, with around 7.5 hours are considered optimal.
2. Sleep regenerates and repairs the body
During sleep, our body begins the process of regenerating and repairing what has been worn-out during the day. In order to carry out this maintenance process, the body winds down most of its functions. In deep sleep, the heart rate decreases, the blood pressure drops, breathing becomes slower and shallower and the muscles relax. Many functions take place only during the deep sleep phase. These include hormone production, wound healing and the regeneration of the immune system.
3. What happens if we sleep too long?
Interestingly, Professor Kripke found that people who regularly sleep for eight hours, instead of 7.5, have a 13% higher risk of dying from illnesses such as cancer and heart problems. That figure rises to 23% with nine hours’ sleep, and as much 34% with ten hours’ sleep. The reason why is unknown however it is important to note that it’s Ok to sleep a little longer or shorter than the ideal values. What’s important is to stick to your own sleep pattern.
4. Around 30% of the population have problems falling asleep at night
There are many reasons why some people struggle to fall asleep at night, with so many distractions such as TV, a snoring partner and bright lights from laptops and smart phones, it’s no surprise getting that early shut-eye can be difficult for many.
5. Sleep affects your weight
“The duration of nocturnal sleep is especially important to how the body burns its fat and regulates its muscle building,” says Plamen Penev, professor of medicine at the University of Chicago. People who sleep for less than 7.5 hours per night reduce their fat burning by 55%, because if you don’t sleep enough the body increases its breakdown of muscle tissue by 60%.
6. Sleep affects your beauty
A recent study by Professor John Axelsson asserted that a rested face is instantly judged to be healthier and therefore more attractive. Additionally, someone who is already perceived as being attractive can appear less so when they haven’t had enough sleep. Professor Baron identified in a study, that subjects who hadn’t had enough sleep had less elasticity, unevenly pigmented and considerably more wrinkled skin”.
7. A lack of sleep can actually make us ill
The risk of getting an infection triples if you haven’t had enough sleep. Our immune system works mostly at night. If we aren’t getting enough sleep, it emits a chemical substance that makes us tired. If you’re sick or feeling run-down, your immune system will create the perfect working environment for healing when you’re asleep, this is because the body’s defence is far more effective at this time and is able to focus on fighting infections.
8. Sleep affects our ageing process
Sleep is when our bodies renew themselves after their daily battle against ageing. Once we’re asleep our metabolism changes and starts a comprehensive self-healing process. Up to 50 million damaged cells a second are replaced with fresh ones. while we sleep at night, the skin begins its work. In fact, between 8pm and 3am, it has eight times more blood flow, emits less water and restricts the production of sebum which lubricates the surface of the skin. What’s more, the basal cells in our skin divide seven times faster than during the day and speed up the nightly repair process.
9. A lack of sleep can increase the risk of many health issues
Less than five hours sleep per night for an extended period can lead to high blood pressure. It is stressful for our body and is expressed in the form of a faster heartbeat increasing risk of cardiovascular disease. It can also slow down metabolism raising blood sugar levels. This can lead to obesity and Type 2 diabetes. Sleep disorders such as Sleep Apnoea increase the risk of breast cancer, especially in post-menopausal women. In extreme cases, a cardiovascular disease caused by a lack of sleep can lead to a stroke. It can also disturb the formation of white blood cells (leukocytes), weakening our immune system.
10. A lack of sleep can increase the risk of mental illness
A lack of sleep can lead to excessive sensitivity to pain, and increased levels of anxiety. Chronic fatigue reduces the neurotransmitters in the brain that are responsible for our moods. This can lead to low moods or even depression. Fewer than six hours sleep can affect our attention span and memory.
*All factual information has been taken from the article ‘Everything you need to know about sleep’ pg 29-32