The glow of your smartphone, tablet or laptop may be getting in the way of a good night’s sleep. Melatonin is the hormone responsible for telling your body it’s time to sleep. But, that blue-ish glow from your electronics inhibits the release of melatonin.
Under normal circumstances, the pineal gland, a pea-size organ in your brain, begins to release melatonin a few hours before your bedtime. Its job is not to put you to sleep, but it reduces alertness and puts your body in a state of readiness for sleep. Light of any kind, but particularly the blue light emitted from electronic devices, interferes with the release of melatonin from the pineal gland. You don’t even have to be looking at the light directly – if your partner is working into the wee hours – the soft glow can be enough to interfere with your sleep as well.
Recent research has found that teenagers in particular are most susceptible to the effects of blue light. During adolescence, the circadian rhythm shifts and teens feel more awake at later hours in the night. Turning on the TV or surfing the net just before bedtime pushes off that sleepy feeling until even later, thanks to the blue light. Early school start times mean a less than desirable amount of sleep for teens.
In a 2014 poll, the National Sleep Foundation asked parents to estimate the amount of sleep their children were getting. More than half said their 15-to-17-year-olds routinely slept for seven hours or fewer, despite the recommended amount of 8 ½ to 10 hours. Alarmingly, 68 percent of these teens were also said to keep an electronic device (TV, computer, video game, smart phone or tablet) on all night. Sleep quality was better among children aged 6 to 17 who always turned their devices off: 45 percent of them were described as having excellent sleep quality vs. 25 percent of those who sometimes left devices on.
Light researcher Mariana Figueiro of the Rensselaer Polytechnic Institute in Troy, N.Y. studies how light affects human health. Her most recent research focused on determining which electronics emit enough blue light to affect sleep. She first compared the melatonin levels of adults and teenagers after looking at computer screens. When exposed to just one tenth as much light as the adults, the teens suppressed far more melatonin than adults. She then studied iPads. After using iPads at full brightness for two hours, melatonin levels were significantly reduced in both groups.
We have to remember that all light after dusk is “unnatural.” It used to be that people went to bed when the sun set and got up when it rose. In fact, a 2013 study found that people who spent a week camping in the Rocky Mountains, exposed only to natural light and no electronic devices, had their circadian rhythms reset with the rise and fall of the sun. This happened to all of the campers whether they were self-described night owls or early birds. Our bodies and sleep habits are extremely susceptible to light conditions. So, in order to get the best sleep possible, remove electronic devices from the bedroom. This is especially important for children.
Charge your phone in another room so you’re not tempted to check your email “one last time.” Avoid watching TV in the hour or so before going to bed. Making these small adjustments can have a huge impact on the quality of your sleep.