The current situation of sleep among contemporary young people: they don't want to sleep except for the time they go to bed, and they want to sleep the rest of the time.
Staying up late seems to have become people's daily routine, after a busy day of study and work, they are always reluctant to fall asleep early, but want to play for a while, and play a little more, as if this can make up for the entertainment time during the day, this way of staying up late is also nicknamed "revenge staying up late" by netizens.
Of course, it is not okay to lack sleep for a long time, and many people choose to catch up on sleep on weekends, trying to make up for the nights they stay up for a week in two days on weekends.
But is it really good for the body to catch up on sleep on the weekend?
Not sleeping enough and sleeping irregularly are considered staying up late.
A good night's sleep consists of two elements, one is to sleep regularly, and the other is to get enough sleep. If you don't sleep regularly, it can lead to endocrine disruptionsIf you don't get enough sleep, you will feel tired. Therefore, not only is it considered to stay up late if you don't sleep enough, but you also stay up late if you sleep irregularly.
How serious is the situation of people not getting enough sleep today?
According to the "China Sleep Research Report (2023)", the sleep index of Chinese residents in 2022 will be 678 points, the average sleep duration of respondents per night was 74 hours, nearly half of the respondents slept less than 8 hours per night on average, 1679% of the respondents slept less than 7 hours per night on average, and young respondents aged 17-26 had the worst self-rated sleep quality.
Source: News** screenshot.
And sleep-deprived staying up late has an impact on people in all aspects.
First of all, staying up late is likely to lead to obesity. Studies have shown that sleep deprivation is associated with a growth hormone-releasing peptide-leptin ratio. Two-night sleep restriction (4 hours per night) resulted in an 18% decrease in leptin levels, a 28% increase in growth hormone releasing peptide levels, a 24% increase in hunger, and a 23% increase in appetite. That is, sleep deprivation increases appetite and promotes energy intake and storage of fat cells by inhibiting leptin and stimulating growth hormone-releasing peptide.
Staying up late can cause irreversible damage to the human brain. A study in the United States proved that children who slept less than 9 hours a night had smaller brain regions responsible for memory, intelligence, and well-being than children who slept healthy. And, after two years, this difference is still there, which illustrates the long-term damage to the brains of sleep-deprived people.
Staying up late can also affect your condition. A UK study showed that people who slept less than five hours were on average 20 percent more likely to be diagnosed with chronic diseases such as heart disease, cancer and diabetes within 25 years, compared to those who slept seven hours. In addition, people who sleep less than 5 hours have a 30% increased risk by age 50, by 32% at age 60, and by age 70, the risk rises to 40%. The study also found that people who slept less than 5 hours had a 25% higher risk of dying prematurely than those who slept normally.
Source: Reference [10].
Not getting enough sleep is enough to destroy your health, but studies have shown that irregular sleep has as much impact on your health as not getting enough sleep.
Researchers from Augusta University in the United States and City University of Hong Kong in China studied 6,052 adult subjects with an average age of 50 years and found that regular sleep habits helped slow down the aging process. The biological age of the subjects with irregular sleep was about 9 months older than that of the subjects with regular sleep.
Specifically, the biological age of subjects with unstable sleep duration, more catch-up sleep, greater variation in sleep onset time, and large differences in sleep on weekdays and weekends was 063 years, 052 years, 074 years and 0Around 77 years.
Source: Reference [12].
After further adjusting the sleep duration, efficiency and other factors, more catch-up sleep, large changes in sleep onset time, and large differences in sleep on weekdays and weekends were still significantly correlated with biological age.
A study conducted by Monash University in Australia and Harvard University in the United States has a similar conclusion.
The study surveyed 88,094 people and collected 480 cases of dementia, which were then rated for their sleep patterns. The average sleep regularity score of the participants was 60 points, with the top 5% of those who scored from childhood to adulthood having the most irregular sleep with an average score of 41, and those who scored in the bottom 5% had the most regular sleep with an average score of 71.
The results of the study showed that subjects with irregular sleep had a higher risk of developing dementia. Subjects with the lowest sleep regularity scores had a 53% higher risk of dementia compared to those with a general sleep pattern.
Source: Reference [13].
All kinds of studies are warning us that no matter what type of staying up late, it is almost harmful to the human body, and it is no wonder that the International Agency for Research on Cancer of the World Health Organization wants to list staying up late as a category 2A carcinogen!
Therefore, in order to minimize the harm caused by staying up late, many people choose to "tear down the east wall and make up the west wall" and adopt a "punk health" attitude
Staying up late on weekdays and sleeping less?Then make up for it on the weekend, and the total sleep time is enough!
But in fact, catching up on sleep on the weekend does not necessarily restore the body to a normal state, but may further harm the body's health.
Catching up on sleep hurts the body?
The first thing to point out is that weekend sleep is not useless, if it's just a cycle, i.e., only a week of staying up late on weekdays and catching up on weekends, then it's still useful.
Pjovic et al. at Pennsylvania State University in the United States conducted an experiment in which they asked the subjects to sleep only 6 hours for 4 consecutive nights, and 10 hours for the next two nights, and then studied the removal of toxins from the participants' brains.
The researchers found that the participants had a significant increase in drowsiness after the restriction of sleep time, and also returned to normal levels after sleep recovery. At the same time, levels of interleukin-6, a marker of inflammation, were also significantly elevated after sleep restriction, and the inflammatory response returned to normal after sleep recovery.
That said, catch-up sleep is still useful.
However, the participants' concentration decreased significantly after sleep time was restricted, and even when sleep time was restored, the participants' concentration did not improve completely. Therefore, short-term weekend catch-up sleep can solve some of the sleep problems, but by no means the whole story.
A study by the Sleep and Time Biology Laboratory at the University of Colorado in the United States has proved that catching up on sleep on weekends cannot compensate for the damage caused by staying up late, and even exacerbates the damage.
The researchers found that sleep deprivation led to a decrease in systemic insulin sensitivity, and it is worth noting that while insulin sensitivity decreased for all subjects, it decreased by only 13% for those who did not catch up on the weekends and 27% for those who made up sleep on the weekends, which means that weekend sleep not only did not prevent the reduction in insulin sensitivity associated with sleep deprivation, but also worsened the situation.
Source: Ref. [11].
The study also found that catching up on sleep on weekends disrupts circadian rhythms and imbalances melatonin secretion.
After catch-up sleep over the weekend, there was a loss of consistency between the time of melatonin change and the time of sleep. Originally, the secretion of melatonin changes with day and night. Generally, it begins to secrete around 8 p.m. and rises rapidly at 11 p.m. to promote the human body to enter deep sleep. It gradually drops from 2 to 3 a.m. and reaches its lowest point at 8 a.m., reminding people that it's time to get up. On Monday morning, the second working week of the experiment, the melatonin drop was significantly delayed.
This may explain why everyone was so sleepy on Monday morning, because melatonin hadn't dropped to its lowest ......
Source: Ref. [11].
Similarly, long-term sleep deprivation has been shown to have a lasting adverse effect on hematopoietic stem cells that cannot be eliminated by restoring sleep.
Specifically, chronic sleep deprivation led to significant changes in the number of immune cells in all subjects, i.e., an increase in the number of immune cells, and changes in the genetic structure of the cells, which limited the differentiation of hematopoietic stem cells into lymphocytes and drove them to differentiate into myeloid cells. Over time, the clonal diversity of hematopoietic stem cells in the human body decreases. Even after sleep returns, hematopoietic stem cells retain this genetic structure.
Cameron McAlpine, Ph.D., co-corresponding author of the study, believes that the reduction in the overall diversity of the hematopoietic stem cell population and aging are important factors in inflammatory and cardiovascular diseases.
In this way, it is okay to rely on weekend sleep once or twice once in a while to recover your body, but in the long run, you may still hurt yourself. Let's have a regular schedule and sleep every day, after all, the body is the capital of the revolution.
References: 1] Cameron McAlpine et al sleep exerts lasting effects on hematopoietic stem cell function and diversity，journal of experimental medicine 2022，doi:10.1084/jem.20220081.
2]faust l，feldman k，mattingly sm，et al. deviations from normal bedtimes are associated with short-term increases in resting heart rate. npj digit med. 2020 mar 23;3:39. doi: 10.1038/s41746-020-0250-6. pmid: 32219180; pmcid: pmc7090013.
3]how sleep helps to process emotions. retrieved may 16th，2022 from
4] John Spyckman, Lina Zhang. (2014).The physiology of weekend catch-up sleep. Science World (01), 108-109
5] Peng Zhilin, Zheng Ruoying, Hu Xiaoqing, Zhang Dandan. The memory consolidation effect of sleep on infant and toddler learning. Advances in Psychological Science.
6] Wang Xunqiang, Wang Chengmin, Xiong Ying. (2022).Research progress on the effect of adult sleep on obesity. Preventive Medicine (09), 898-901doi:10.19485/j.cnki.issn2096-5087.2022.09.007.
7] Yang Yan. (2023).Effect of Supplemental Sleep on Cognitive Impairment Associated with Acute Sleep Deprivation (M.S.**, Shandong University).
8] Zhong Xuemei. (2022).Study on the Effect of Sleep on Attention and Psychomotor Speed, Executive Function, and Memory in Young Students (M.S.**, Southwest Medical University).
9] Survey, analysis and research on the situation of college students sleeping late[J].SUN Fengmei;Julie;Hu Caihong;Chen Xiao. Science and Education Collection, 2016(12).
10]sabia s， dugr**ot a et al. (2022) association of sleep duration at age 50， 60， and 70 years with risk of multimorbidity in the uk: 25-year follow-up of the whitehall ii cohort study. plos medicine 19(10): e1004109.
11]depner cm，melanson el，eckel rh，et al. ad libitum weekend recovery sleep fails to prevent metabolic dysregulation during a repeating pattern of insufficient sleep and weekend recovery sleep. curr biol. 2019 mar 18;29(6):957-967.e4. doi: 10.1016/j.cub.2019.01.069. epub 2019 feb 28. pmid: 30827911.
12]xiaoling wan et al. day-to-day deviations in sleep parameters and biological aging：findings from the nhanes 2011-2014. sleep health. volume 9, issue 6, december 2023, pages 940-946.
13]stephanie r. yiallourou et al. association of the sleep regularity index with incident dementia and brain volume. neurology jounals. january 23, 2024 issue 102 (2).
Author: Min Min Luren.
*: China News Weekly.