People sleep three times, and their lives are thinner than paper! Study of 3 million people: Sleeping more than 8 hours increases the risk of death
"Use the most expensive eye cream to stay up late at night." This sentence describes the sleep conditions of many Chinese people.
According to the "2022 Chinese National Healthy Sleep White Paper" jointly released by the China Sleep Research Association and other institutions, 44% of young people aged 19-25 stay up late until after midnight, and poor sleep has gradually become a common pain point for young people.
How many people have experienced this situation?
Every day when I wake up in pain, I cry out in my heart, "I must go to bed early tonight!!"
As a result, after lying in bed at night, there are all kinds of "true fragrances":
"I will sleep when I finish this video"
"I fell asleep after playing this game"
In the end, by the time he recovered, it was already one or two in the morning.
Sleep is closely related to human health and longevity . How to sleep and how long to sleep are all important.
1. You may be fooled by the "8-hour sleep theory"
According to data released by the World Health Organization, about 27% of the world's people have sleep disorders . Long-term lack of sleep can damage blood vessels and brain health, affect normal life, and easily cause or aggravate cardiovascular and cerebrovascular diseases, diabetes, obesity, depression, Alzheimer's disease and other diseases.
In the past, many experts have been advocating the "8-hour sleep theory", believing that it takes 8 hours of sleep every night to be healthy. This theory has also been widely recognized by people.
So how many hours of sleep do you need to sleep every night for your health? In response to this question, a study published in the Journal of the American Medical Association (JAMA) in 2021 gave the answer.
Researchers at the National Cancer Center in Japan selected 322,721 people from Japan, China, Singapore and South Korea, with an average age of 54.5 years, and 55.3% (178,542) of women.
Participants were divided into 6 groups based on the amount of sleep each day, 5 hours or less, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours or more. During the follow-up period, there were 19,419 deaths in men and 13,768 deaths in women.
It was found that the number of women who slept for 7 hours was the largest, accounting for 33.8%, while the number of men who slept for 8 hours was the largest, accounting for 35.1%. Seven hours of sleep was the lowest for all-cause mortality, cardiovascular disease mortality, and other-cause mortality in both men and women .
Simply put, people who slept 7 hours a day had the lowest risk of death from all causes, while sleeping too little (<5 hours) or sleeping too much (>10 hours) significantly increased the risk of death .
Sleep experts point out that for different groups of people, the sleep time is also different: it is best for teenagers to sleep 9 hours a day, adults 18-64 years old need about 7-8 hours of sleep , and people over 65 years old need 6.5-7.5 hours of sleep hours or so.
When is the healthiest time to sleep?
A prospective cohort study published in the European Heart Journal by a research team from the University of Exeter in the United Kingdom found that the prime time to fall asleep is between 10-11 o'clock , because of cardiovascular disease at this time. Lowest risk.
2. People sleep three times, and their lives are thinner than paper!
In addition to the length of sleep affecting health, some bad sleep habits also endanger human health.
1. Sleep late
The results of a cohort study published in the American Journal of Cardiology by a research team from Keele University in the United Kingdom showed that too much sleep is associated with increased cardiovascular disease morbidity and all-cause mortality.
The researchers reviewed 74 cohort studies, including 3,340,684 participants, and found that the association between sleep duration and risk of cardiovascular disease and risk of all-cause mortality showed a J-shaped curve. The risk of vascular events and all-cause mortality was higher .
Among them, 9 hours of sleep per night was associated with a 14% increased risk of all-cause mortality; 10 hours of sleep was associated with a 30% increased risk of all-cause mortality; and 11 hours of sleep was associated with a 47% increased risk of all-cause mortality .
2. Inversion sense
Zhao Wei, deputy chief physician of Tianjin University Teda Hospital, said that early, delayed or reversed sleep time is a circadian rhythm disorder.
Common manifestations are difficulty falling asleep, difficulty maintaining sleep, and increased daytime sleep time, which can easily induce cardiovascular, gastrointestinal, metabolic, cognitive, and emotional diseases , leading to impaired learning, work, and other functions.
3. Emotional sense
A study in the Journal of Neuroscience shows that falling asleep with an angry mood exacerbates negative emotions because sleep strengthens memory , especially emotional memory.
So, don't go to bed immediately when you are angry, otherwise the angry mood will recover more slowly.
3. Is "turning back to sleep" a sign of good sleep quality?
Most sleep disorders are manifested as insomnia and difficulty falling asleep. Some people lie in bed and fall asleep within five minutes. Does it mean that the quality of sleep is high?
Li Taoping, director of the respiratory and sleep center at Southern Hospital , said that most people who fall asleep quickly may be at risk of developing sleep apnea syndrome (SAS).
If the time from lying in bed to falling asleep is less than 5 minutes, it is considered that the sleep latency is too short , indicating that the person is in a state of drowsiness and lethargy, which is one of the common symptoms of sleep apnea syndrome (SAS). So, it doesn't mean that falling asleep quickly means good sleep quality.
What should I do to improve sleep quality?
1. Do not eat or exercise 2-3 hours before bedtime
Eating too much dinner or eating before going to bed will increase the secretion of gastric acid and increase the burden on the stomach. And exercise will make the brain in a state of excitement, which in turn affects the quality of sleep.
2. Take a shower or soak your feet 1-2 hours before going to bed
Taking a bath 1-2 hours before going to bed can raise your body temperature and relax your muscles. When you go to bed, your body temperature just drops, which can help you fall asleep. Before going to bed, soaking your feet with warm water at 40°C-42°C can promote blood circulation, accelerate metabolism, and help improve sleep quality.
3. Choose comfortable bedding
Bedding made of synthetic satin, polyester and other materials cannot expel moisture and will make people hotter as they sleep. It is recommended that the product should be made of perspiration-wicking and breathable materials such as pure cotton and wool .
If you are allergic to dust or mold, it is recommended to use anti-allergen mattresses and bed covers, and to wash them frequently.
4. Keep your sleeping environment dark
Exposure to light before and during sleep can inhibit the secretion of melatonin, which in turn affects sleep quality.
If the window of the rest space leaks light, you can install blackout curtains ; if it is not possible to completely block the light, you can also wear a blackout eye mask when sleeping.
Sleep plays an important role in human health. Sleeping too long or too short can harm your health. In addition to sleep time, pay attention to sleep time, sleep habits, and sleep quality.
References:
[1]Svensson， T.， Saito， E.， Svensson，A. K.，et al. (2021). Association of sleep duration with all-and major-cause mortality among adults in Japan， China， Singapore， and Korea. JAMA network open，4(9)，e2122837-e2122837.
[2] "When a person sleeps three times, his life is thinner than paper"? What are the three senses? These kinds of abnormalities may be because the body is "calling for help"... Popular Science China, 2022-04-06
[3] Take 1 minute to measure your sleep quality, 12 ways to save all kinds of "bad sleep". Life Times, 2019-05-29
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