Why Does Sleep Really Matter?

By Dr Magdy Badran

Sleep is the single most effective thing you can do to reset the health of your brain and body. This is true for adults, teenagers and children alike.

Sleep is as important as food for keeping us alive; without it, rats will die within two or three weeks – the same amount of time that it takes to die from starvation.

Sleep is common to mammals, birds, reptiles, and amphibians. It has been conserved through evolution, even though it prevents us from performing other useful tasks, such as eating, reproducing and raising young.

It affects almost every type of tissue and system in the body, from the brain, heart, lungs, metabolism, immune function and mood.

When we sleep, our bodies rest, conserving energy and decreasing blood pressure, heart rate, breathing and body temperature. At the same time, our brains remain active, laying down memory, restoring daytime mental functioning and carrying out processes that lead to physical growth.

Humans spend about one-third of their lives asleep. How much sleep we need depends on inpidual requirements, including the age. The amount of sleep a person needs will depend on how they feel and their productivity.

Sleeping fewer than 7 hours in every 24 hours is classified as short sleep duration. Many people are not getting enough sleep. This has been linked to factors such as shift-work and other multiple jobs, spending time watching television and using the Internet.

There are 5 stages of sleep. When you sleep you move through various stages that help to restore and regulate physical and mental health. Most of us should experience around 4-5 sleep cycles a night, and, during these cycles, your body will move through different stages of NREM (Non-Rapid Eye Movement) and REM (Rapid Eye Movement) sleep.

The first stage of sleep is known as ‘NREM 1’ or the ‘transitional stage’. During this stage, you will be feeling drowsy. It’s also the stage of sleep where you experience muscle twitches. You’re only supposed to spend 5% of your total sleep time in stage one, if you suffer from insomnia or stress, you may spend longer in this phase.

In the second stage of sleep, your breathing and heart rate will gently start to slow down and your body temperature will decrease. Eye movement will stop, and your brain waves will slow down, preparing you for deep sleep. You will spend around 50% of your time sleeping in this second stage.

Too little sleep in NREM2 could impact your ability to learn and retain knowledge. Sleep spindles are brief bursts of activity and recent research has even indicated that sleep spindles could be related to your ability to learn, intellectual ability and memory consolidation. They’re called “spindles” for the shape they create when monitored using an EEG.

Recent evidence suggests the spindle is highly correlated with tests of intellectual ability and may serve as a physiological index of intelligence. Further, spindles increase in number and the duration of sleep following new learning and are correlated with performance improvements.

Sleep also prepares your brain, almost like a dry sponge, getting it ready to soak up and learn new information the next day.

Without sleep, you can’t form or maintain the pathways in your brain that let you learn and create new memories, and it’s harder to concentrate and respond quickly.

During stages 3 & 4 your blood pressure will slowly drop. It’s very difficult to rouse someone from a deep sleep. This is the sleep stage where your body will repair itself and it can last for up to an hour; during these stage hormones such as Human Growth Hormone are released and the blood supply to your muscles will increase. This stage of sleep is also extremely important for the immune system.

Sleep is a nocturnal gift to boost your immune system. Deep sleep boosts immunological memory. Human immune system and sleep are both associated and influenced by each other. Sleep deprivation could suppress immune system function, makes a living body susceptible to many infectious agents and even makes the flu vaccine less effective.

Without sufficient sleep, your body makes fewer cytokines, a type of protein that targets infection and inflammation, effectively creating an immune response. Cytokines are both produced and released during sleep.

Stage Five – REM sleep is sometimes referred to as ‘dream sleep’ and it the stage where you will start to dream. Your brain activity will start to increase, as will your heart rate and blood pressure. It’s an incredibly important stage of sleep for your memory and emotional health.

Children and young adults are most vulnerable to the negative effects of sleep deprivation. Sleep deprivation is associated with higher mortality risk and the loss of productivity at work. A chronic lack of sleep, or getting poor quality sleep, increases the risk of disorders including high blood pressure, fatigue, cardiovascular disease, diabetes, and depression.\

Sleep deprivation has been linked to a higher risk of premature death. Lack of sleep has been implicated as playing a significant role in tragic accidents involving airplanes, ships, trains, automobiles, and nuclear power plants.

There are about 100 sleep disorders. Examples include excessive daytime sleepiness, difficulty getting to sleep or staying asleep, abnormal movements, behaviors or sensations during sleep and sleep paralysis.

Tips for a good night's sleep include having the right pillow, mattress, and covers, keeping to the same sleeping and waking times, including at weekends, listening to relaxing music, using nasal strips to reduce snoring and drinking chamomile tea.

Use your bed only for sleep. Avoid daytime naps that reduce bedtime sleepiness. Avoid watching screens, browsing the internet, and so on, before bedtime and do not do these activities in bed. Keep the bedroom quiet and dark, with comfortable bedclothes.

Avoid alcohol, caffeine, tobacco smoking, and heavy meals before bedtime. Try to avoid tension before sleeping. Exercise may be beneficial for sleep. Do vigorous exercise during the day and relaxing exercise, such as yoga, before bedtime.

Melatonin is a natural hormone made by the pineal gland. This is a pea-sized gland located just above the middle of the brain. During the day the pineal is inactive. When the sun goes down, the pineal is "turned on" and begins to actively produce melatonin. As a result, melatonin levels in the blood rise sharply and you begin to feel less alert.

Sleep becomes more inviting. Melatonin levels in the blood stay elevated for about 12 hours - all through the night - before the light of a new day when they fall back to low daytime levels by about 9 am.

Bright light inhibits the release of melatonin. That is why melatonin is sometimes called the "Dracula of hormones" as it only comes out in the dark.

Sleep hygiene practices may help the body to regulate melatonin synthesis properly. Use of artificial light, including the light emitted by televisions, phones, and computers, can trick the brain into thinking it is still daylight. This may inhibit melatonin synthesis and delay sleep.