(STUDY FINDS) — We’ve all heard the adage “you’re only as old as you feel,” but what if your actual age and perceived age don’t quite match up? It turns out that this concept, known as subjective age, can have profound implications for your health and well-being. According to a new study by researchers at Stockholm University, one of the key factors influencing how old you feel might be something you do every night: sleep.
The study, published in the journal Proceedings of the Royal Society B, included two parts: a cross-sectional survey of 429 adults between 18 and 70 and an experimental sleep study involving 186 participants. Both investigations aimed to uncover how sleep habits and sleepiness affect subjective age.
In the survey, participants were asked how many days in the past month they felt they hadn’t gotten enough sleep. They also rated their current level of sleepiness on a scale from 1 (extremely alert) to 9 (extremely sleepy). The results were striking: for each additional day of insufficient sleep, participants felt 0.23 years older on average. Moving from the most alert to the most sleepy rating was associated with feeling a whole decade older.