So this is why they call it beauty sleep.
Getting inadequate shut-eye can make you feel older than you actually are, according to new research.
The two-part study, published Wednesday in the Proceedings of Royal Society B, found that poor slumber can tack on more than four years to how old people feel, while getting ample rest has the opposite effect, making people feel more rejuvenated and youthful.
Lack of sleep has been associated with adverse health outcomes, such as poor mental health, Type 2 diabetes and heart disease.
“Age is more than just the perception,” study author Leonie Balter, of the Karolinska Institute in Sweden, told New Scientist. “We know those who feel younger than their actual age live healthier and longer.”
In the first part of the study, the researchers surveyed 429 people aged 18 to 70, asking how old they feel and how many days out of the past 30 that they felt they slept poorly.
“The relationship between subjective age and calendar age showed the expected pattern: as individuals’ calendar age increased, they felt progressively younger than one’s actual age,” the study authors wrote.
Those who reported sufficient sleep every night of the previous month also said they felt about five years younger than their actual age, while each additional day of poor slumber shockingly tacked on nearly three months to the volunteers’ subjective age.
For the second part of the sleep study, 186 participants aged 18 to 46 were asked how old they felt after two days with nine hours of shut-eye per night, compared to two days with only four hours of sleep per night.
After restricting their slumber for only two days, the sleepy volunteers reported feeling more than four years older than their calendar age on average — whereas they felt nearly three months younger after a good night’s sleep.
“Sleep has a major impact on how old you feel and it’s not only your long-term sleep patterns,” Balter told The Guardian. “Even when you only sleep less for two nights that has a real impact on how you feel.”
The team of researchers also found that night owls often felt older than their age despite getting ample rest, yet early birds were affected more by lack of sleep.
“It’s important to realize how malleable subjective age is,” Balter added. “If we can make people feel younger, they may be able to have the associated benefits, such as being more willing to take on new experiences and being socially active and physically active.”
