Want to Feel Young? Take Care of Your Sleep

Researchers at Stockholm University have found that sleep quality affects how you age. This study was published in the journal Proceedings of the Royal Society B, on Wednesday (27/3/2024).

Previous research shows that feeling younger than one's actual age is associated with longer and healthier lives. Even, there is support for subjective age to predict actual brain age, where those who feel younger have a younger brain.

"Considering that sleep is very important for brain function and overall well-being, we decided to test whether sleep holds the secret to maintaining a youthful appearance," said Leonie Balter, a researcher in the Department of Psychology at Stockholm University, who wrote this study together with John Axelsson, a neuroscience expert from the Karolinska Institute.

Also read: Sleeping too much can harm your health

In the first stage of this study, 429 individuals aged 18 to 70 were asked about their age, how many days in the last month they had insufficient sleep, and how sleepy they felt. It turns out that after every night of insufficient sleep in the past month, participants felt on average 0.23 years older.

In the second phase of the study, researchers tested whether lack of sleep does indeed make participants feel older. For this reason, they conducted an experimental study of sleep restriction involving 186 participants aged 18 to 46 years.

Participants were asked to reduce their sleep time for two nights, only sleeping for four hours in bed each night, and to sleep enough at other times for two nights, with nine hours in bed each night.

After sleep restriction, participants felt an average of 4.4 years older than when they had sufficient sleep. The effect of sleep on subjective age seems to be related to how sleepy individuals are.

Feeling very energetic due to getting enough sleep is correlated with feeling four years younger than one's actual age. Meanwhile, extreme drowsiness is associated with feeling six years older than one's actual age.

“This means that going from feeling fit to feeling sleepy adds 10 years to a person's life,” says Leonie Balter.

Also read: Sleeping less than five hours increases the risk of chronic disease

From these findings, according to Balter, the implications for our daily lives are clear, which is that maintaining the quality of our sleep is very important in keeping our youthful feelings.

"This, in turn, can encourage a more active lifestyle and behaviors that enhance health. Because a feeling of youthfulness and fitness is important to motivate us to be active," he said.

Insomnia disorder

Several other studies have also found that poor sleep habits are strongly associated with long-term chronic health conditions.

For example, a study by Soomi Lee from The Pennsylvania State University and a team in the journal Psychosomatic Medicine in February 2024 found that insomnia sufferers over a 10-year period were at higher risk of developing chronic health conditions, including cardiovascular disease, diabetes, and depression.

The change from feeling fit to feeling sleepy adds 10 years to a person's age.

A study by Xiao Tan from Zhejiang University, China, in the journal Age and Aging in September 2023 stated that insomnia and short sleep duration in middle age increase the risk of dementia.

In this study, researchers used data from 22,078 participants in the Swedish National March Cohort, who were initially free from dementia and stroke. The incidence of dementia during a follow-up period averaging 19.2 years was determined through national records.

Researchers have found that compared to participants without insomnia, those who reported symptoms of insomnia experienced a greater incidence of dementia during the follow-up period.

Difficulty initiating sleep is also a risk that increases the risk of dementia. However, difficulty maintaining sleep or waking up in the morning is not associated with an increased risk of dementia.

Short sleep duration is also linked to an increased risk of dementia. Insomnia symptoms increase the risk of dementia in participants who slept at least seven hours compared to those who did not experience insomnia, but this did not occur in participants who slept short (less than seven hours).

Among those with insomnia, short sleep duration did not increase the risk of dementia.

The American Academy of Sleep Medicine and the Sleep Research Society set a minimum of seven hours of sleep per night. The problem, according to a Yougov Survey in 17 international markets in December 2023, is that more than half the population in these 17 countries sleeps for seven hours or more every night.

Also read: Short naps have many benefits, but over time they are actually dangerous

In Indonesia, according to this survey, as many as 51 percent of adults sleep less than seven hours per day. In fact, 24 percent of them sleep less than five hours per day. This means that only 48 percent of the population sleep according to the standard or more.

The key is regular exercise

The latest study written by Erla Bjornsdottir, a psychologist from Reykjavik University, Iceland, and a team at BMJ Open on Tuesday (26/3/2024) provides a recipe for reducing the risk of insomnia.

According to this study, consistent exercise 2-3 times a week in the long run is associated with a decreased risk of current insomnia and the ability to sleep for the recommended 6-9 hours per night.

Regular exercise is associated with better overall health. Several studies suggest that physical activity improves sleep quality and alleviates chronic insomnia symptoms, according to researchers.

In this study, researchers assessed the frequency, duration, and intensity of weekly physical activity as well as insomnia symptoms, nighttime sleep, and daytime sleepiness among middle-aged adults from 21 centers in nine European countries.

A total of 4,399 study participants (2,085 men and 2,254 women) were drawn from the European Community Respiratory Health Survey.

After adjusting for age, gender, body weight (BMI), smoking history, and other conditions, researchers found that those who remain physically active are less likely to experience sleeping difficulties and insomnia symptoms.

Those who remain active significantly (55 percent) are more likely to have normal sleep, significantly less likely (29 percent) to have short sleep (six hours or less), and 52 percent less likely to have long sleep (nine hours or more).

Those who became active were 21 percent more likely to sleep normally than those who were constantly inactive.

Researchers acknowledge that they cannot objectively assess the changes in physical activity levels between two points in time and that all elements depend on subjective assessments through questionnaires.

The results of this research are in line with previous research showing the beneficial effects of physical activity on insomnia symptoms.

So, if you want to feel young, then get enough sleep, at least seven hours a day. In order to get enough sleep, the body needs sufficient and regular physical activity.