'The earlier you sleep, the earlier you die', is there any scientific basis? Oxford University research has the answer

The 38-year-old Mr. Chen often worked overtime before and suffered from severe lack of sleep. One day, he suddenly fell on the post. The emergency doctor arrived and diagnosed sudden cardiac death. Fortunately, the rescue was timely and his life was saved. Since then, Mr. Chen has quit his previous job and changed to a new job that is much more relaxed, and his sleep requirements have become very high.

In order to meet the standard of sleep time, Mr. Chen starts to prepare for bed at 7:30 after returning home from work every day, and does not wake up until 6:00 the next morning . Once he sleeps less than 8 hours due to insomnia, he will feel tired, have difficulty concentrating, and become irritable and irritable .

In order to solve this problem, Mr. Chen specially went to the hospital to hang up a number, hoping to seek the assistance of professional doctors. After a series of examinations and doctor's consultations, Mr. Chen was diagnosed with "perfect sleep disorder", which means that excessive attention and attempts to improve sleep data worsen sleep problems.

In the eyes of many people, "early to bed and early to rise" means a healthy life and rest. Some people may even go to bed early at 8 or 9, and get up at 6 or 7 the next day. They must sleep for 8 hours a day. Is this routine really healthy?

1. The earlier you sleep, the earlier you die?

"Early to bed and early to rise for good health" is a daily routine that many people have been following, but in recent years, research results have found that going to bed early will increase the risk of death .

In April 2021, an epidemiological prospective study involving 110,000 people in 21 countries in the journal Sleep Medicine found that early going to bed (before 10 pm) or late going to bed (after 12 midnight or later) Both increase the risk of major cardiovascular events and the risk of all-cause mortality.

Among them, those who went to bed early had a 29% increased risk, and those who went to bed late increased the risk by 11%.

However, this study has certain limitations. First, the findings only found a prior association between bedtime and major cardiovascular events and mortality, but did not imply that early or late bedtime was associated with cardiovascular events or death .

Secondly, the risk of morbidity and mortality of cardiovascular disease will be affected by a variety of factors, including the patient's disease history (such as whether there is a chronic disease), lifestyle behavior, etc. The combined value increase in risk decreased from 29% to 9% .

Coincidentally, in the same year, another research team from Oxford University in the United Kingdom found that there are health risks in going to bed early and going to bed late. The study was published in the European Heart Journal Digital Health.

The study recruited 88,026 participants from the UK Biobank between 2006 and 2010, with an average age of 61 (43-79) and 58% women.

They wore wrist devices to collect data on sleep onset and wake times over 7 days, and completed assessments and questionnaires on physical fitness, lifestyle, etc., as well as cardiovascular disease (including heart attack, chronic haemorrhagic heart disease, heart failure, stroke, and transient ischemic attack) were diagnosed.

During an average follow-up period of 5.7 years, a total of 3172 people developed cardiovascular disease. Among them, those who fell asleep at midnight or later had the highest incidence, and those who fell asleep at 10-11 p.m. had the lowest incidence .

After adjusting for factors such as age, gender, weight, and blood pressure, the researchers found that compared with those who fell asleep at 10-11 pm:

• People who went to bed at midnight or later had a 25% increased risk of cardiovascular disease;
• People who fell asleep at 11-12pm had a 12% increased risk of cardiovascular disease;
• People who fell asleep before 10 p.m. had a 24 percent increased risk of cardiovascular disease.

That said, the healthiest time to sleep is between 10-11pm.

This study, the most extensive study to date to assess the relationship between sleep duration and cardiovascular disease, clearly demonstrated an association between sleep duration and cardiovascular disease, and the association was stronger in women. Time to sleep has emerged as an independent risk factor for cardiovascular disease risk.

2. Sleeping late VS not getting enough sleep, which is more harmful?

Some people's work may require night shifts, and they may sleep late, but can make up for sleep during the day; some people stay up late, but get up early the next day to go to work or school, which leads to lack of sleep... Late night or not enough sleep, which is more dangerous?

Every life on Earth has a biological mechanism called a "biological clock", and humans are no exception. The biological clock is an invisible clock that basically aligns with the 24-hour cycle of light and dark on Earth.

The human body's biological clock is dominated by the suprachiasmatic nucleus of the brain's hypothalamus, which controls many aspects of life, including eating and sleeping times, the ability to run fast, focus, etc. Even the immune system is in the biological clock. run under the guidance .

When the sleep time violates the laws of the biological clock, people will feel tired and uncomfortable, and in the long run, it will bring serious harm to physical and mental health . Therefore, sleeping late and not getting enough sleep are both harmful to the body.

If you go to bed too late or not enough sleep for a long time, you may face the following consequences:

1. to make people stupid

Long-term staying up late or lack of sleep can cause symptoms such as fatigue, lack of energy, inattention and memory loss, resulting in problems such as frequent dreams, poor sleep quality and neurasthenia, and even depression and anxiety in severe cases. health problems.

2. Induce high blood pressure

When staying up late or lack of sleep, people will be in a state of tension, blood pressure will be higher than normal, and it is easy to induce high blood pressure.

In recent years, the incidence of cardiovascular and cerebrovascular diseases has shown a trend of increasing year by year and getting younger. One of the important reasons is that modern young people like to stay up late.

3. Get fat, get ugly

Long-term staying up late or lack of sleep will affect the body's secretion of "leptin", which will lead to the accumulation of fat in the body, and people will gradually gain weight.

In addition, staying up late or lack of sleep can also cause the skin cells to fail to obtain adequate nutritional supply, thereby accelerating the aging of the skin and making the skin pale and dull.

4. Affect vision

Long-term staying up late or lack of sleep will not only damage the surface of the eyes, but also cause symptoms such as dark circles and bags under the eyes. Long-term overload use of the eyes can also lead to functional loss of vision, and in severe cases, cataracts and even blindness .

It should be noted that if you often stay up late, even if you make up for sleep during the day, you may not be able to make up for it .

Because staying up late for a long time will disturb the normal biological clock of the human body and the repair of the cerebral cortex, which will affect the function of various organs and tissues in the body, and even sleep supplementation cannot fundamentally solve these problems.

3. Always wake up in the middle of the night, what does it imply?

Have you ever tried to wake up suddenly at three or four in the middle of the night, and then have a hard time falling back asleep? The reason for waking up in the middle of the night may be related to incorrect sleeping methods, such as sleeping too early, taking a long nap, room too hot, looking at mobile phones before going to bed, drinking alcohol before going to bed, etc.

However, if you frequently wake up in the middle of the night, be aware of the possibility of illness, especially mild depression, breathing problems (such as colds, seasonal allergies, enlarged tonsils, etc.), sleep apnea, gastroesophageal reflux and Thyroid problems (overactive or underactive thyroid), etc.

So how can we improve the quality of sleep every day? Xiaojiu shares 4 suggestions with you:

• Before going to bed, turn off electronic products such as mobile phones and tablet computers to prevent blue light in the bedroom. Sleeping pillows should be comfortable, of moderate height and firmness;
• Don't overeat at dinner, and don't eat 1 hour before bed. Drink less water before going to bed, don't drink alcohol, you can drink some hot milk in moderation to help you fall asleep;
• Pay attention to the right amount of exercise before going to bed, do not do strenuous exercise within 4 hours before going to bed, you can do some low-intensity activities, such as Tai Chi, yoga, etc.;
• Avoid smoking within 4 hours of bedtime, as the nicotine in cigarettes can make you high. In addition, sleeping pills should be used with caution, and do not rely on medication to aid sleep.

Adequate sleep and a circadian schedule are essential to keep your mind and body functioning properly. Going to bed too early, too late, or not getting enough sleep can damage our physical and mental health in the long run.

Therefore, it is recommended that you stay up late as little as possible, go to bed at 10-11 o'clock every night, and ensure that you have 7-8 hours of sleep every night.

References:

[1]Wang， C.， Hu， B.， Rangarajan， S.， Bangdiwala， S. I.， Lear， S. A.， Mohan， V.， . . . Yusuf， S. (2021). Association of bedtime with mortality and major cardiovascular events： An analysis of 112，198 individuals from 21 countries in the Pure Study. Sleep Medicine， 80， 265-272. doi：10.1016/j.sleep.2021.01.057

[2]Nikbakhtian， S.， Reed， A. B.， Obika， B. D.， Morelli， D.， Cunningham， A. C.， Aral， M.， & Plans， D. (2021). Accelerometer-derived sleep onset timing and cardiovascular disease incidence： A UK biobank cohort study. European Heart Journal - Digital Health， 2(4)， 658-666. doi：10.1093/ehjdh/ztab088

[3] 14 reasons for waking up in the middle of the night [J]. Family Medicine. Happy Health, 2020(04): 3.

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