Two nights of broken sleep can make people feel years older, finds study

Two nights of broken sleep are enough to make people feel years older, according to researchers, who said consistent, restful slumber was a key factor in helping to stave off feeling one's true age. Psychologists in Sweden found that, on average, volunteers felt more than four years older when they were restricted to only four hours of sleep for two consecutive nights, with some claiming the sleepiness made them feel decades older. "Sleep has a major impact on how old you feel and it's not only your long-term sleep patterns," said Dr Leonie Balter, a psychoneuroimmunologist at the Karolinska Institute in Stockholm and first author on the study. For each day of poor sleep the volunteers felt on average three months older, the scientists found, while those who reported no bad nights in the preceding month felt on average nearly six years younger than their true age. In the second study, the researchers quizzed 186 volunteers aged 18 to 46 on how old they felt after two nights of plentiful sleep, in which they stayed in bed for nine hours each night, and two nights when they slept for only four hours a night. After two nights of restricted sleep, the participants felt on average 4.44 years older than when they had ample sleep. "This study tells us that a bad night of sleep can impact how we feel the day after, but what are the cumulative effects of bad sleep for months and years?".