By: Nicola Davis of The Guardian
Many people complain they do not get enough sleep, and it seems they are right to be concerned. Researchers have found that adults under the age of 65 who get five or fewer hours of sleep for seven days a week have a higher risk of death than those who consistently get six or seven hours’ shut-eye.
However the effect of short sleeps over a few days may be countered by a later lie-in. The research found that individuals who managed just a few hours’ sleep each day during the week but then had a long snooze at weekends had no raised mortality risk, compared with those who consistently stuck to six or seven hours a night.
“Sleep duration is important for longevity,” said Torbjörn Åkerstedt, first author of the study, at the Stress Research Institute, Stockholm University, and Karolinska Institute, also in the Swedish capital.
The study, published in the Journal of Sleep Research, is based on data from more than 38,000 adults, collected during a lifestyle and medical survey conducted throughout Sweden in 1997. The fate of participants was followed for up to 13 years, using a national death register.
Åkerstedt said researchers had previously looked at links between sleep duration and mortality but had focused on sleep during the working week. “I suspected there might be some modification if you included also weekend sleep, or day-off sleep.”
Once factors such as gender, body mass index, smoking, physical activity and shift work, were taken into account, the results revealed that those under the age of 65 who got five hours of sleep or under that amount seven days a week had a 65% higher mortality rate than those getting six or seven hours’ sleep every day. But there was no increased risk of death for those who slept five or fewer hours during the week but then managed eight or more hours’ sleep on weekend days.