Why does getting enough sleep matter?

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By Dorottya Harangi, Health, Medicine & Veterinary Science co-editor

When I was at university, I had friends who pulled all-nighters before every exam. As someone who loves her sleep and would never dream of skipping a night of rest, it was such a foreign concept to me. What are the consequences of being sleep-deprived and what can we do to improve the odds of getting a good night’s sleep?

Young people are more vulnerable to sleep deprivation than older people. Twenty-five percent of Canadian adults between the ages of 18-34 are not getting the recommend 7-9 hours of sleep and 50% of them have difficulty either falling asleep or staying asleep.

Lack of sleep is attributable to either lifestyle or sleep disorders. Shift work, academic demands, and poor sleep hygiene are among the lifestyle factors related to lack of sleep. Insomnia, the inability to fall asleep, stay asleep or go back to sleep, and sleep apnea, when breathing repeatedly stops and starts during sleep, are common sleep disorders.

Effects of Sleep Deprivation

Many university students will stay up late studying and preparing for exams. However, this lack of sleep may actually be hurting their academic performance. Photo: Barney Yau, Unsplash.

What are the impacts of not getting enough sleep, other than being cranky and tired for the next few days? Lack of sleep can impair our cognitive functions, motor skills and memory. Researchers at MIT and Harvard looked at how sleep quality, duration and consistency affected the academic performance of college students. They found a strong correlation between the amount of sleep that the participants got and their academic performance. This correlation is based on the average nightly sleep across the whole semester. There was no correlation between pulling an all-nighter before a test and the test grade. They also found that consistent sleep is important—you cannot compensate for lack of sleep during the week by oversleeping on the weekends.

Working memory is the first cognitive system affected by sleep deprivation. Working memory transfers information between short term and long-term memory. One experiment kept the participants awake for 36 hours. This resulted in increased reaction times and decreased accuracy when the participants were given cognitive tasks.

Lack of sleep can also affect our physical health. Studies show that people who average less than seven hours of sleep per night are at a higher risk for obesity, diabetes, and cardiovascular problems like hypertension. It appears that as the average number of sleep hours decreases, the risk of adverse physical manifestations later in life increases.

Why do some people need more sleep than others?

If you think you need more sleep than the average person to function, you may be right. Researchers used fruit flies to explore a genetic explanation for individual sleep requirements. They segregated flies with very long or very short sleep patterns and found that these sub-populations had genetic mutations that could account for these sleep differences.

The need for extra sleep could also be due to a sleep disorder such as hypersomnia or Kleine-Levin syndrome. Both disorders cause people to sleep much more than average but only affect a very small subset of the population and are not a typical cause for needing more than average sleep.

Non-genetic causes for needing above average sleep time may be linked to depression or a traumatic brain injury. Researchers found a very strong link between depression and disordered sleep, either too much or too little sleep. Most depressed people experience insomnia—trouble falling and staying asleep—but for young adults, hypersomnia—feeling tired after a full night of sleep—is also common. The link between depression and disordered sleep is significant. Even if a person’s other depression symptoms improve, if their disordered sleep symptoms persist, they have a significantly higher chance of relapsing.

People with a traumatic brain injury (TBI) commonly experience an increased need for sleep, as well as feeling tired during the daytime. Roughly 50% of TBI patients experience some form of sleep-wake disturbance, which can adversely affect their quality of life.

A new cause of sleep deprivation

Sleep deprivation has been an issue for years, but COVID has made things worse. An increased number of people are experiencing insomnia as a result of COVID-19—it’s called covid-somnia.

These people are unable to fall asleep or stay asleep because they are afraid of getting COVID, experience heightened concern about loved ones, are anxious about not being able to go to work, and do not have any social contact with others leading to a feeling of isolation. This situation can lead to a misuse of sleep medications.

Canadian sleep research

The Canadian Institutes of Health Research Institute of Circulatory and Respiratory Health (CIHR-ICRH) conducts research on heart, lung, brain, stroke, blood, blood vessels, critical and intensive care and sleep. The CIHR-ICRH stresses the importance of getting adequate rest and warns of the consequences of not doing so. In 2020, the CIHR-ICRH funded nine research studies that focused on the connection between sleep and COVID. These research initiatives covered topics including virtual interventions to help promote good sleep habits for students and determining the effects of COVID on mental health.

In addition to funding sleep research, CIHR-ICRH partners with organization such as the Canadian Sleep Society (CSS) to recognize researchers in the field and put on training events. In 2021, the Distinguished Lecturer in Sleep Sciences award went to Dr. Douglas Bradley, a professor at the University of Toronto and researcher at the University Health Network. His research examines the link between sleep apnea and cardiovascular health problems. He also helped develop an at-home sleep apnea monitoring device.

How you can improve your sleep hygiene

Although many of us use our phones in bed while we wind down for the night, this habit could be making it harder for us to fall asleep. Photo: Nubelson Fernandes, Unsplash.

Getting a good night’s sleep is critical for your mental and physical health. There are some things that you can do to prepare yourself to sleep well. Some things to consider include:

  • Developing and maintaining a consistent bedtime schedule and routine
  • Making your bedroom sleep-friendly—quiet, dark, relaxing, comfortable temperature
  • Avoiding caffeine, alcohol or large meals close to bedtime
  • Avoiding screens—smartphones, computers, TVs—close to bedtime
  • Avoiding napping during the day
  • Exercising regularly

Sleep is crucial to both our short-term and long-term wellbeing. Not regularly getting enough sleep can have cognitive and physical repercussions. This is why it is so important to get those recommended 7-9 hours of sleep each night as consistently as possible.

Feature image: Most people need 7-9 hours of sleep but many Canadians don’t hit that benchmark. What happens to us when we are sleep deprived and what can we do to improve the odds of getting a good night’s sleep? Photo: bruce mars, Unsplash.

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