On average, the French sleep 6h42 per night during the week and 7:26 hours at rest according to a Public Health France Barometer dating from 2017. Many people therefore mostly sleep less than the recommended 7 hours and 45% of 25-45 year olds believe that they sleep less than they need according to Inserm. Indeed, a good sleep schedule is essential for physical and mental health. Santé Publique France reminds that sleep affects the risk of diabetescardiovascular diseases, accidents, that it contributes to the regulation of blood circulation, hormone production, the immune system, that it eliminates toxins from the brain which allows slow down your agingand he plays on stress managementmemory, or even on the regulation of moods.
Does sleep have an impact on the perception of age?
But sleep also acts on subjective aging according to researchers from Stockholm University (Sweden), who published, on March 27, 2024, a double study in the newspaper Proceedings of the Royal Society B. The goal ? Examine the impact of lack of sleep and the sleepiness on the subjective experience of age. As a reminder, drowsiness corresponds to a state between wakefulness and sleep, unwanted and sometimes uncontrollable. “Since sleep is essential for brain function and overall well-being, we decided to see if it holds any secrets to maintaining a youthful feeling”Leonie Balter, one of the authors of the study, said in a statement.
For their research, the scientists conducted two studies: the first to ask 429 people aged 18 to 70 their subjective age, the number of days they had lacked sleep in the previous month, and how much they were sleepy, then a second experimental study of sleep restriction with 186 participants, aged 18 to 46 years.
Sleep: Suffering from sleepiness can significantly increase subjective age according to researchers
At the end of this work, the researchers noted that for each night of insufficient sleep in the previous month, the participants felt on average 0.23 years older. After a sleep restriction induced for the study, the latter estimated themselves on average 4.4 years older than when they had gotten enough sleep. For scientists, these effects of sleep on perceived age seem to be linked to the degree of sleepiness : they observed that a state of alert was associated with the feeling of being 4 years younger than one’s real age, whileextreme sleepiness was linked to the feeling of being 6 years older than one’s real age. “It means that going from a state of alertness to a state of drowsiness adds around ten years to the perceived age“, explained Leonie Balter.
In terms of chronotypes, morning people were associated with feeling subjectively younger when they slept more, but at a higher subjective age when exposed to sleep restriction, compared to evening people, and those of intermediate types.
Sleep and subjective age: discoveries likely to act effectively on aging according to scientists
Furthermore, the researchers recall the results of previous studies, which demonstrated that feeling younger than one’s actual age was associated with a longer, healthier life. They add that subjective age has also been shown to predict actual brain age, because people who feel younger have younger brains.
According to the scientists of the study, this should encourage you to take care of your sleep schedule. “It is essential to preserve our sleep to maintain a feeling of youth”, insists Leonie Balter. She concludes that “this can in turn promote a more active lifestyle and encourage health-promoting behaviors, as feeling young and alert is important for our motivation to be active”.
Sources :
- Sleep and subjective age: protect your sleep if you want to feel young – Proceedings of the Royal Society B – 27 mars 2024
- Want to feel young? Protect your sleep – EurekAlert! – 27 mars 2024
- Sleep, Shedding light on our nocturnal activity – Inserm
- Sleep – Public Health France
