Medical myths: how much sleep do we need?

Medical myths: how much sleep do we need?

In this special article, we will clear up some myths about sleep duration. Among other things, we ask if anyone can really get 5 hours of sleep every night. We are also looking into whether sleep deprivation can be fatal.

While we all know that sleep is vital to maintaining good health, many questions remain unanswered. And over the millennia, various myths and half-truths have arisen and entrenched.

This feature is the second and final part of our series on sleep myths.

This time we'll focus on the myths about how much sleep the average person needs. We also discuss sleep, the effects of too little or too much sleep, and sleep in the animal kingdom.

1. Everyone needs 8 hours

As with many aspects of human biology, there is no universal approach to sleep. In general, research shows that for healthy young people and adults with normal sleep, 7-9 hours is a good time.

However, the story gets a little more complicated. The amount of sleep we need every day varies depending on our lifestyle:

  • newborns need 14-17 hours
  • babies need 12-15 hours
  • babies need 11-14 hours
  • preschoolers need 10-13 hours
  • school-age children need 9–11 hours
  • teenagers need 8-10 hours
  • adults need 7–9 hours
  • older people need 7-8 hours

You can teach your body to sleep less

There is a widespread rumor that you can train your body to sleep less than 7-9 hours. Unfortunately, this is a myth.

According to experts, anyone needs less than 6 hours of sleep to function properly. While some people may argue that they feel good with limited sleep, scientists believe that it is more likely that they are used to the negative effects of sleep deprivation.

People who sleep 6 hours or less each night get used to the effects of sleep deprivation, but that doesn't mean their bodies need less sleep. Cynthia LaJambe, sleep expert at the Pennsylvania Transportation Institute at Wingate, explains:

“Some people think they are more adaptable to being awake, but are actually working at a lower level. They don't realize it because functional decline happens so gradually."

“At the end of the day, the effects of sleep deprivation cannot be denied. And accustoming the body to sleep less is not the best option.”

— Cynthia LaJambe

However, it's worth noting that some rare people seem to actually function normally, getting less than 6,5 hours of sleep each night. There's evidence that it could be due to a rare genetic mutation, so it's probably not something to learn from.

2. Daytime sleep is bad for health.

As a general rule, experts recommend that people avoid daytime naps in order to get a better night's sleep. However, if someone missed sleep during previous nights, tactical sleep can help pay off some of the accumulated sleep deprivation.

A good sleep duration is about 20 minutes. This gives the body enough time to recharge. People who sleep much longer than this time may mean that they are falling into a deep sleep, and when they wake up they feel lethargic.

Daytime naps are relatively common in the United States, but "siesta" is the norm in some countries. Naturally, our bodies tend to lose energy at the beginning of the day, so perhaps taking a nap at this time is more natural than avoiding sleep until night.

Do not miss:  How to Stop Bad Habits: 9 Scientifically Proven Methods

After all, the vast majority of mammals are polyphasic sleepers, which means they sleep for short periods of time during the day.

In a larger discussion regarding the effects of daytime sleep, the authors explain that daytime naps in people who are not sleep deprived can lead to "subjective and behavioral improvements" and improvements in "mood and subjective levels of sleepiness and fatigue." They found that people who sleep had improved performance on tasks such as "addition, logical reasoning, reaction time, and character recognition."

However, not all naps are the same. There are many options, such as the time of day, the length and frequency of naps. One author explains:

"Epidemiological studies show a reduction in the risk of cardiovascular and cognitive dysfunction through the practice of short sleep several times a week."

The author also acknowledges that more research is needed to understand how nap-related factors affect health outcomes. 

It is also important to note that if a person experiences extreme fatigue during the day, this may be a sign of a sleep disorder, such as sleep apnea.

Scientists will need to do more research before they can finally dispel all the myths and mysteries about naps.

3. All animals sleep.

Since humans sleep and our companion animals seem to sleep, many people assume that all animals do the same. It is not true. The authors of the article "All do the animals sleep? »explain:

“Some animals never exhibit a state that fits the behavioral definition of sleep. Others suspend or significantly reduce sleep patterns for many weeks postpartum or during seasonal migrations without any subsequent sleep deprivation.”

They also explain that some marine animals, reptiles, fish and insects do not enter REM sleep.

Since sleep is not just an absence of consciousness, but a rhythmic cycle of various neural patterns, it is difficult to determine whether an animal is sleeping or resting.

“More than 50 of nearly 60 vertebrate species have been tested across all criteria that define sleep,” the authors explain. “Of these, some do not meet the criteria for sleep at any time in their lives, and others appear to be able to significantly reduce sleepiness or go without sleep for long periods of time.”

4. More sleep is always better

While many people find it difficult to get enough sleep to feel rested, some regularly sleep longer than their body needs. You might think that this might endow these people with superpowers.

However, researchers are establishing a link between sleep duration and poor health. For example, one scientist who followed 276 adults for 6 years concluded:

"The risk of developing obesity was increased in those who slept short and long hours compared to those who slept moderately, with an increase in risk of 27% and 21%, respectively."

This finding persisted even when the scientists controlled for analysis of age, sex, and baseline body mass index. According to some researchers, sleep duration may also affect mortality.

In a meta-analysis published in the journal Sleep concluded: "Both short and long sleep durations are important predictors of death in prospective population-based studies."

5. Lack of sleep can be fatal.

Not a single person has been recorded dying from lack of sleep. It is theoretically possible, but as far as scientists can ascertain, this is unlikely.

Do not miss:  What are the ways to restore the nervous system

However, it is understandable why this myth could take root. Sleep deprivation, as many people can attest, can be terrifying. However, the case of Randy Gardner shows that extreme sleep deprivation is not fatal.

In 1965, when Gardner was only 16 years old, he participated in a sleep deprivation experiment. In total, he did not sleep for 11 days and 24 minutes, which equals 264,4 hours.

All this time, he was closely watched by fellow students and scientists dealing with sleep issues. As the days passed, the sleep deprivation symptoms worsened, but he survived. So why has this myth persisted?

The belief that sleep deprivation kills may have its roots in the 1980s. Rechtshaffen and colleagues found that if they deprive rats of sleep using a certain experimental method, they die in 2–3 weeks.

In their experiments, the researchers placed rats on a disc suspended above water. They constantly measured their brain activity. When the animal fell asleep, the disc moved automatically, and the rat had to act to avoid falling into the water.

Despite the loss of life in Rechtshaffen's experiments, later studies have shown that this is not the norm. Rats deprived of sleep in various ways do not die. In addition, other researchers who have used the disk method on pigeons have found that it was not fatal to these creatures.

However, sleep deprivation is not painless for a person. As early as 1965, Gardner's parents were worried about their son. They asked Lieutenant Commander John J. Ross of the U.S. Naval Medical Neuropsychiatric Research Unit in San Diego to observe him. It describes a steady decline in function.

For example, by the second day, it became harder for Gardner to focus his eyes. By day 4, he struggled to focus, became irritable and uncooperative. On day 4, he also reported his first hallucination and megalomania.

On day 6, Gardner's speech became slower, and on day 7 he became slurred as his memory deteriorated. Paranoia broke out on the 10th day, and on the 11th day his expression and tone of voice became expressionless. His attention and memory were greatly reduced.

However, he did not die and does not appear to have experienced any major health problems.

Another reason the myth persists that sleep deprivation can be fatal may be due to a condition called fatal familial insomnia. People with this rare genetic disorder cannot sleep. However, when people with the condition die, it is due to accompanying neurodegeneration, not lack of sleep.

While sleep deprivation probably won't kill you outright, it's worth adding a warning: overwork increases the risk of accidents. According to the National Highway Traffic Safety Administration, "sleepy driving kills - it claimed 2017 lives in 795."

Similarly, the consideration in a report published in 2013: "Approximately 13% of work-related injuries may be related to sleep problems." So, while sleep deprivation is not literally fatal, it can be fatal.

In addition, if we continually deprive our bodies of sleep for months or years, it increases the risk of developing several conditions, including cardiovascular disease, hypertension, obesity, type 2 diabetes, and some forms of cancer.

In conclusion

In general, we should try to get 7-9 hours of sleep each night. Sounds simple, but in our neon, noisy, noisy life, it's harder than we'd like. All we can do is keep trying to give sleep the space it needs.

Only through constant research will we eventually unravel all the mysteries of sleep.

Please rate the article
Translate »