We already know what constitutes recommended levels for body mass index, cholesterol, blood glucose, and other measures of human health. Now, for the first time, we know the consensus on the recommended amount of sleep for a healthy adult (aged 18 to 60).
David F. Dinges, PhD, director of the Unit for Experimental Psychiatry and chief of the division of sleep and chronobiology, and Michael Grandner, PhD, an instructor in Psychiatry and member of the Center for Sleep and Circadian Neurobiology, were part of a committee of experts brought together by the American Academy of Sleep Medicine (AASM) and Sleep Research Society (SRS) who evaluated the current scientific literature and found that seven hours of sleep per night, on a regular basis, is the recommended amount of sleep required to promote optimal health in healthy adults. The panel shared the findings at SLEEP 2015.
The group reported this month that regularly sleeping less than seven hours per night has been found to be associated with health problems, including weight gain and obesity, hypertension, depression, and decreased longevity. Those experiencing less than seven hours also risk impaired immune function, impaired performance, increased errors, and greater risk of accidents behind the wheel, on the job, and other important aspects of daytime life.
Using the RAND Appropriateness Method, which included multiple rounds of review, discussion, and voting, the committee brought together by the AASM and SRS conducted a comprehensive, 12-month review of 5,314 published articles on scientific sleep research to find this threshold.
The recommendation serves as a critical public health message, but the panel also makes it clear that behavioral, health, environmental, and genetic factors may affect how much sleep a specific individual may need.
The team did not set a maximum number of hours of sleep per night, as the committee determined that there was not enough of a consistent documented risk associated with longer sleep.
Although many experts in the sleep research community and governmental organizations applauded the committee for producing this critical public health message, the panel also reaffirmed that healthy sleep needs include sufficient sleep duration, adequate sleep quality, timing, and regularity, and the absence of sleep disorders.
“There are caveats in the statement that say if you’re concerned at all, you should see your doctor, but if you’re otherwise healthy and you’re sleeping well now, you’re not falling asleep driving, you’re not having other problems, then arguably, you don’t need to be as concerned,” said Dinges. “When the amounts go below six, the evidence is very strong that the risk of many health-related problems increase.”
These population studies and laboratory studies offer the best advice available on the subject, but recommendations at the population level are difficult to apply every individual.
“This is the recommended amount of sleep for a healthy adult,” said Dinges. “The recommendation does not necessarily apply to sleep need in people with disorders, diseases, and pathologies that can affect sleep.”
Support for the project came from the AASM, SRS and the Centers for Disease Control (1U50DP004930-01) and Prevention and the full report is scheduled to be published in the August issue of the journal SLEEP.
“This is the first time representatives from the leading scientific sleep organizations have all come together to make a public health statement, but hopefully this is not the last time,” said Grandner. “This is just the beginning of this conversation. Public interest in sleep is growing, and information like this, from an authoritative and unbiased source, could potentially help move the conversation forward.”