The importance of sleep for the brain and health

Dr Lynda Shaw explains why sleep is so important to our physical and mental wellbeing.
sleep for the brain and health

We often ignore the importance of sleep for the brain and health. Sleep is vital for our physical and mental health and is the time our body repairs itself and the brain forms connections that help you process your day and lay down memories. Good quality sleep is as important as eating a balanced diet, reducing stress and exercise are to our physical and mental health.

Sleep stages

When you sleep, you go through five cycles of sleep that last approximately one and half hours (shorter for children). Disturbed sleep or insufficient hours of sleep will result in fewer cycles. In each sleep cycle, firstly you enter a very light stage of sleep, progressing into stage two, a light sleep known as NREM (non-rapid eye movement) where the brains waves slow down preparing for deep sleep. Stage three and four are deep sleep, where brain waves slow down to delta frequency crucial for repair. Then we enter rapid eye movement (REM) sleep, which is when we dream and is vital for mental and emotional regulation. 

What is good quality sleep?

The average person needs between seven to nine hours of good quality sleep a night. Nearly half (48%) of UK adults report that they don’t get enough sleep. with 23% only having five hours a night. Two thirds (67%) of UK adults regularly experience disrupted sleep.

The importance of good quality sleep

A night or two of poor sleep won’t harm you, but long-term sleep deprivation will lower your quality of life and put you at risk of serious medical conditions, as well as make you feel moody, impair your concentration and problem-solving skills, increase your risk of depression and you may develop relationship and work issues.  

Here are ten reasons on why sleep is so important

  • Look after your physical health by sleeping well: Research shows that ongoing insufficient sleep puts you at risk of serious medical conditions likes heart disease, obesity, cancer and diabetes.  This is because your regulatory hormone levels become off balanced and there is an increase in inflammatory processes. Your immune system will become weakened, so you will also be more susceptible to common colds. It is thought that prolonged awake time can destroy a certain type of brain cell (locus ceruleus), which are key to controlling our awake and alert state and can even lead to irreversible injury to the brain.
  • Look after your mental health by sleeping well: One or two nights of disrupted or inadequate sleep will make you feel short tempered, moody and muddled. Prolonged sleep reduction will put you at serious risk of disorders like depression and anxiety. Studies show that people with depression often have less than six hours sleep per night, meaning they do not have enough deep sleep and REM sleep, which is when the brain is restored. In the brain of a patient with chronic insomnia the neurons are more ‘excitable’ and will make the person feel ‘wired’ which leads to trouble sleeping. In these situations, the brain may need training to let you go to sleep for example using hypnotherapy.
  • Sleep makes you more productive at work: Sleep is essential for brain function as it is when we consolidate information and memories from the day, and improves memory, performance, problem solving and creativity. Forcing your brain to work well into the night at the cost of proper sleep is not conducive to well-being nor career success.  
  • Good quality sleep improves learning: Sleep helps learning by helping you concentrate and learn new information, consolidate memories and establishes stronger communications between brain cells. This means information is transmitted from one part of the brain to another more efficiently, improving your ability to recall the information you’ve learnt. Studies have found that sleep helps us to preserve our greatest memories and downgrade those that are of lesser importance.  Without sufficient sleep, our brains will almost certainly find it more difficult to distinguish between the two.
  • Sleep deprivation is linked to spikes in days off sick: Your immune system relies on sleep to stay healthy.  During sleep your hormones are kept in balance and anti-inflammatory chemicals are released. By not getting enough sleep you are putting yourself at risk of more frequent colds, tummy bugs as well as serious health conditions like high blood pressure.
  • Sleep means putting safety first: Sleep deprivation will decrease your coordination and balance and may make you drowsy putting you at serious risk of accidents and injury whilst driving, at work or doing domestic jobs. Sleep deficiency has been known to impair driving ability with similar responses to those who have had too much alcohol to drink.
  • A bad night’s sleep will make you cranky: Sleep loss will increase the likelihood of mood swings, feeling low, angry or depressed, decrease motivation and reduce resilience to challenging situations which can affect your work, social life and relationships.
  • Sleep is when our bodies do their daily repair jobs: When you sleep your body sends more oxygen to your muscles and repairs any muscle injuries. You are at higher risk of back pain and musculoskeletal injury if you don’t sleep enough.  Also, the flow of cerebrospinal fluid in the brain washes away toxins that have built up during the day, including metabolic by products found in Alzheimer’s Disease (AD) are flushed away which may reduce the risk of AD.
  • Sleep helps manage your weight: Sleep deprivation has been linked to weight gain, risk of obesity and associated health concerns. Studies have shown that in sleep deprived people, the chemical leptin (which makes you feel full) lowers. At the same time, the chemical ghrelin rises which makes you hungry the result of which might mean that you eat more when you haven’t had enough sleep. When tired, it is tempting to eat more as we feel with need extra fuel to get through the day.

Improve your sex drive and fertility by sleeping more: It’s not only mental and physical health which can be improved by sleep, but also sexual health. In men, sleep deprivation lowers testosterone levels leading to lowered sex drive, fertility problems and hair loss. In women, ongoing sleeplessness reduces the secretion of reproductive hormones, lowering their chance of becoming pregnant.

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Last modified: June 10, 2021

Written by 11:48 am Health