Sleep problems in teenagers can be improved in just one week by limiting their evening exposure to blue light-emitting screens on phones, tablets, and computers, according to new research.
Recent studies have indicated that exposure to too much evening light, particularly the blue light emitted from screens on smartphones, tablets, and computers, can affect the brain’s circadian clock and the production of the sleep hormone melatonin, resulting in disrupted sleep time and quality.
The lack of sleep doesn’t just cause immediate symptoms of tiredness and poor concentration, but can also increase the risk of more serious long-term health issues such as obesity, diabetes and heart disease.
Other studies have suggested that sleep deprivation related to screen time may affect children and adolescents more than adults. But no studies have fully investigated how real-life exposure is affecting sleep in adolescents at home and whether it can be reversed, according to researchers at the Netherlands Institute of Neuroscience, the Amsterdam UMC and the Dutch National Institute for Public Health and the Environment.
For their study, the researchers investigated the effects of blue light exposure on adolescents at home.
They found that those who had more than four hours a day of screen time had, on average, 30 minutes later sleep onset and wake up times than those who recorded less than one hour a day of screen time.
The researchers then conducted a randomized controlled trial to assess the effects of blocking blue light with glasses and no screen time during the evening on the sleep pattern of 25 frequent screen users.
Both blocking blue light with glasses and screen abstinence resulted in sleep onset and wake up times occurring 20 minutes earlier, and a reduction in reported symptoms of sleep loss in participants, after just one week, the researchers reported.
“Adolescents increasingly spend more time on devices with screens and sleep complaints are frequent in this age group,” said Dr. Dirk Jan Stenvers from the department of Endocrinology and Metabolism of the Amsterdam UMC.
“Here we show very simply that these sleep complaints can be easily reversed by minimizing evening screen use or exposure to blue light. Based on our data, it is likely that adolescent sleep complaints and delayed sleep onset are at least partly mediated by blue light from screens.”
Stenvers said that the researchers are now interested in whether the relationship between reduced screen time and improved sleep has longer lasting effects, and whether the same effects can be detected in adults.
“Sleep disturbances start with minor symptoms of tiredness and poor concentration, but in the long-term we know that sleep loss is associated with increased risk of obesity, diabetes and heart disease,” he said.
“If we can introduce simple measures now to tackle this issue, we can avoid greater health problems in years to come.”