The optimal sleep duration is not 8 hours?


Many people have heard that "you need to sleep for 8 hours" to get the best sleep. Not getting enough sleep for 8 hours in the long term will affect your health. However, many people have little sleep time, and no matter how much they sleep, they never get enough 8 hours of sleep; some people even feel dizzy and uncomfortable after getting enough 8 hours of sleep.

Is the optimal sleep duration really 8 hours? More and more studies have found that this may be a cognitive misunderstanding!

In 2021, a study covering more than 320,000 Asian adults, "The Relationship Between Sleep Time and Mortality in East Asian Populations," was published in a sub-issue of the Journal of the American Medical Association. The results showed that sleeping 7 hours a night is "Optimal sleep" means that if you sleep for 7 hours a day, all-cause mortality, cardiovascular disease, and other mortality rates will be reduced to the lowest point! But when you sleep for 8 hours, it will increase the risk of death from some diseases!

Unlike most previous European and American studies, this study mainly focused on Asian populations. Researchers collected 320,000 people and found in nearly 14 years of follow-up that there is a "J-shaped association" between sleep time and all-cause mortality - 7 hours of sleep is associated with all-cause mortality, cardiovascular disease and other diseases. Cause death related nadir. in particular:

Male population: Compared with 7 hours of sleep, sleeping more than this value per night, such as 8, 9, and 10 hours, will increase all-cause mortality by 9%, 18%, and 43% respectively; while sleeping less than 5 hours, Participants also had a 16% increase in all-cause mortality.

Female population: Compared with 7 hours of sleep per night, sleeping 1 hour more or less than 1 hour will increase all-cause mortality.

In addition to the risk of all-cause mortality, there was an almost similar association between sleep duration and the risk of death from cardiovascular disease, cancer, and other causes, with a nadir at 7 hours.

Why do some people sleep more and others less? Isn’t it necessary to sleep for 8 hours? In 2009, Dr. Ying-Hui Fu, a Chinese neuroscientist at the Weill Institute of the University of California, San Francisco, who is engaged in sleep-related research, published an article in the top journal "Science" that she and her team " A mutated gene called "DEC2" was found in the mother and daughter of short sleepers. The study found that people who carry the "DEC2 gene" have an average sleep time of 6.25 hours/day, which is much shorter than people in the same family who do not carry this mutation (an average of 8.06 hours/day). Scientists have confirmed that these "natural short sleepers" are not forced to sleep less because of work or other reasons. They sleep less and have more energy than ordinary people.

Not only that, in 2019, Professor Fu's research team discovered two more genes "ADRB1" and "NPSR1" that affect the length of human sleep after first discovering the "short sleep gene". These will cause different people to have different sleep lengths. . Therefore, if you are also a person who sleeps less, don’t be anxious, you may really be a “gifted” person!

"Sleeping more does not mean sleeping better." Jin Ling, chief physician of the Sleep Medicine Center of Nanjing Brain Hospital of Jiangsu Province, said in an interview with Xinhua Daily in March 2022 that there are large individual differences in sleep duration. , any indicator (such as sleep duration, number of times you wake up, time to fall asleep, etc.) is relative. You should judge whether your sleep is good based on your state after getting up the next day. If you feel well rested and energetic when you wake up, and you are not obviously tired from working and studying during the day, you can be considered to have gotten enough sleep at night.

Therefore, don’t worry about whether you should sleep enough for 8 hours. There is only one criterion for judging good sleep - how you feel. If you wake up the next day and feel like you slept well, are full of energy, and don't feel sleepy during the day, you've had a good night's sleep.

Therefore, the criteria for good sleep seem very simple, but in order to have good sleep, the key is to do these 6 points:

  1. Maintain a regular bedtime routine
  2. Many people have irregular schedules due to work or personal habits, and do not go to bed at a fixed time. Over time, the biological clock is disrupted, the schedule is irregular, and the quality of sleep will be reduced.

  3. Don’t do these things before going to sleep
  4. It is not recommended to drink too much water before going to bed, in case you suddenly want to go to the bathroom in the middle of the night; do not bring your mobile phone or computer into the bedroom, as it will become an obstacle to sleep; dinner should be eaten 3 hours before going to bed, and try not to eat it again after that Eat.

  5. Maintain a good sleeping environment
  6. The intensity of light affects the body's circadian rhythm. If you dim the room lights before going to bed and place your body in a darker place, it will be easier for you to fall asleep naturally. In addition, the height of the pillow is not appropriate and the thickness of the quilt is unreasonable, which will indirectly affect the quality of sleep.

  7. Do less exciting things before going to bed
  8. You should do less things that are not conducive to improving sleep quality. Some people watch scary or exciting movies or exercise strenuously before going to bed. These behaviors will excite the cerebral cortex and put the nerves in an over-excited state, which will significantly affect the quality of sleep. decline. Also be careful not to overuse your brain before going to bed. If you have the habit of working or studying at night, you should finish the more troublesome things in advance and do something easier before going to bed to relax your brain and make it easier to fall asleep.

  9. Drink tea and coffee in moderation during the day
  10. Many people want to use coffee to overcome daytime sleepiness, but this method is unsustainable. The intake of coffee, tea, and alcohol will cause sympathetic nerve excitement at night, thereby reducing sleep quality.

  11. Proper exercise to reduce fatigue
  12. If you have a lot of activity during the day, you will naturally feel tired at night. If you fall asleep in time after feeling sleepy, your sleep quality will also improve. Otherwise, it will be difficult to have high-quality sleep without your body feeling tired at all.