The Many Benefits Of Sleep

Last updated: April 10, 2019

Every one of us can see some of the obvious sleep benefits, such as good mood, attention, easy learning, and freshness. We can also notice how all of these benefits disappear after only one night of sleep deprivation.

Research shows that sleep has even more benefits, like boosting our immune system, balancing hormones, improving physical abilities, keeping heart and brain healthy, weight under control, reduces stress and inflammation and more.

Many people choose to sacrifice their sleep for work, fun, or another reason. Recognizing the power of sleep and caring about sleep hygiene can help prevent many diseases and disorders.

Sleep improves learning and memory

Sleep improves our learning and memory. Not only are we able to absorb new information and recall after a good night’s rest, but we also “review” while sleeping. Numerous studies have shown that people are more likely to remember what they had learned if they take a nap after learning.

Memory is consolidated during sleep, meaning that important memories are strengthened and unimportant ones weakened. This way the brain does the maintenance and “frees up” space for new memories.

All sleep stages play a role in keeping the memory in a good shape – light sleep, REM and deep sleep. They repeat cyclically, but not all sleep cycles are the same. In the first half of the night, we have more deep, and in the second, more REM sleep. It is important to sleep long enough in order to reach all sleep stages.

During our night’s rest, nerve cells become smaller and all the wasteful substances are flushed out easily from the system, rebooting the brain so that it is fresh and ready for new challenges of the following day. When those substances build up in the brain, they act as neurotoxins – their plaque is associated with serious diseases like Alzheimer’s.

Sleep makes you faster in thinking and reacting

Alertness is tightly connected to how much sleep we had. It is extremely important to be well rested if you are planning to go behind the wheel.

If you have slept, but feel strong sleep inertia (grogginess), you’ve probably had non-restorative sleep. Non-restorative sleep consequences are similar to those of not having sleep, so be careful – if you have excessive daytime sleepiness, something is probably wrong with your sleep.

However, after a good night’s sleep, your reaction time is much smaller, attention to detail is high and thinking is fast.

Sleep reduces stress and improves mood

When we don’t have enough sleep or are completely sleep deprived, our cortisol (stress hormone) levels rise. In the case of prolonged sleep deprivation, one could experience an inability to fall asleep easily due to high cortisol which keeps the mind alert.

Sleep lowers blood pressure, manages hormones and relieves the informational burden from the brain. REM sleep seems to be linked to emotional stability – when someone is chronically sleep-deprived, they are likely to suffer from depression, anxiety, mood swings, and stress.

Dopamine and serotonin, chemicals which make us feel good, are present at high levels when we’ve had enough sleep.

Sleep reduces inflammation, boosts the immune system and helps the body heal

Human growth hormone peaks during deep sleep. In children, it promotes growth, but in adults, it helps with tissue repair and cell rejuvenation. Wounds and injuries can heal faster with plenty of sleep.

When there is a high amount of stress hormones (for example, due to sleep deficiency), there is more inflammation. Various types of inflammation are linked to heart diseases, cancer, and even diabetes.

On the other hand, plenty of sleep strengthens the immune system, which reduces inflammation and enhances the response of the body to viruses and bacteria.

Poor sleep can interfere with the immune system by disrupting the cells (T cells) which ensure an appropriate immune response. This may lead to the development of autoimmune diseases, as the body starts attacking its own cells.

Sleep keeps weight under control

We feel less hungry when we sleep well. Poor sleep increases ghrelin, our ‘hungry’ hormone, and decreases leptin, the ‘fullness’ hormone. For this reason, many people have a higher calorie intake on days following the lack of sleep.

Moreover, insulin – our glucose regulator – is disrupted and only one night of sleep deprivation increases insulin resistance so much that it brings people into a prediabetic-like state. With longer sleep restriction, insulin problems persist.

Sleep keeps your heart healthy

Short sleep has been linked to an increased risk of high blood pressure in adults. Prolonged high blood pressure is likely to cause heart diseases.

Having enough good quality sleep relieves the tension of the entire cardiovascular system and preserves a healthy heart.

Too much sleep isn’t good as well – a study showed that women who sleep nine hours or more were at a higher risk of having coronary heart disease than those who slept the recommended 7-8 hours.

Sleep balances hormones

Hormones are very easily disturbed by the lack of sleep. Studies have shown that estrogen and testosterone, the female and male reproductive hormones, drop as a response to sleep deprivation. They are also important for sleep quality, metabolism, and mood – when it comes to hormones, usually one problem directly influences another.

Not enough sleep brings excessive eating and poor metabolism, as hormones which regulate them are lacking or become too high, so poor sleep increases the risks of weight gain and diabetes.

Sleep lowers the stress hormone levels and increases growth hormone. Hormonal balance is one of the refreshing aspects of restorative sleep.

Sleep ensures stomach and bowel health

Sleep defends stomach health by decreasing stomach acid secretion. When sleep-deprived, too much acid impairs stomach lining which makes a good environment for ulcer formation.

Patients with insomnia are three times more likely to develop bowel disorders compared to those who have no sleep disorders.

Sleep might decrease cancer risks

A study has shown that cancer patients are extremely likely to suffer from insomnia and excessive daytime sleepiness. Many correlations between cancer and poor sleep have been found.

For example, too much or too little sleep is linked with colorectal cancer, prostate cancer, and breast cancer.

Melatonin, the hormone which makes us sleepy, is known to prevent tumors from developing through many different ways – it kills cancerous cells, increases levels of a protein (TP53) which suppresses tumors, and it also prevents tumors from growing their own blood vessels.

Staying up late and being exposed to artificial light at night messes up melatonin levels by decreasing it. People who stay up late or are awake all night over a prolonged period of time run a higher risk of developing cancer.

As mentioned before, sleep also reduces inflammation and boosts immunity – both have a positive effect when it comes to our body’s natural cancer defense.

Use the sleep benefits

Those who were sleep-deprived for a prolonged period of time can’t just erase the side-effects of not having enough sleep. Research has shown that even after weeks of recovery sleep, the attention levels don’t return to normal.

In order to make the most out of your sleep, follow these simple rules:

  • Avoid alcohol before bed because it prevents you from reaching deep, restorative sleep.
  • Maintain a regular sleep-wake routine so that your body can follow the schedule. This will also make your sleep cycle better, which means waking up at the right time, well-rested.
  • Expose yourself to daylight and do exercises during the day.
  • Sleep in a dark, cool room.

These are only some of the rules for good sleep hygiene, but they will help you get the quality sleep and start enjoying all the benefits proper sleep brings.

Additional resources

  1. Sleep, Learning, and Memory. Healthy Sleep. Harvard. http://healthysleep.med.harvard.edu/healthy/matters/benefits-of-sleep/learning-memory Accessed March 6, 2019.
  2. Roberts D.S, Restorative Sleep Is Vital to Brain Health. Psychology Today. April 6, 2017. https://www.psychologytoday.com/us/blog/the-resilient-brain/201704/restorative-sleep-is-vital-brain-health Accessed March 6, 2019.
  3. Cappuccio F. P, Cooper D, et al. Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies. European Heart Journal. February 7, 2017. https://www.ncbi.nlm.nih.gov/pubmed/21300732 Accessed March 6, 2019.
  4. Pejovic S, Basta M, et al. Effects of recovery sleep after one work week of mild sleep restriction on interleukin-6 and cortisol secretion and daytime sleepiness and performance. American journal of physiology. Endocrinology and metabolism. October 1, 2013. https://www.ncbi.nlm.nih.gov/pubmed/23941878 Accessed March 6, 2019.

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