Two things are necessary for a good night’s rest: switch off all screens in good time beforehand – at a minimum your phone and your computer – and make sure you allow yourself eight hours’ sleep. Adults require between seven and nine hours of sleep.
For a long time, people believed that it was the blue light of screen exposure that disrupted production of the melatonin sleep hormone. Things actually appear to be more complicated than that: it depends on what are you doing on-screen. Stimulation from your email, apps and social media can keep you awake, while a relaxing TV program can send you right to sleep.
Good night’s rest is vital
Research involving nearly 400,000 people in the UK, found at the end of 2019 24 that people who sleep well have a lower body mass index (BMI), smoke less and exercise more. Sleeping well keeps you fit.
The Trimbos-institute prescribes seven to nine hours of sleep per night. Less is not good, but neither is more: sleeping too much or too little is related to obesity, diabetes, cancer, strokes and depression. According to Trimbos it is mainly women, young people, people with an immigrant background and the elderly who sleep poorly. For older people there is a proven cause: as you get older, your biological clock works less efficiently which means among other things, you sleep less well.
Is blue light the bad guy?
Blue light was also regarded for a long time as an important cause of sleep problems. The glow from mobile phones and tablets was said to disrupt the production of melatonin, the hormone that takes care of your sleep-wake cycle. Anyone who sits looking at their phone until late at night can expect to fall asleep less quickly.
However, closer research by the Netherlands National Institute for Public Health and the Environment (RIVM) has shown that the finger was pointed too quickly at blue light as the bad guy. Sleep problems are generally not caused by the blue light – which normally is not bright enough to wreak havoc on hormone management – but rather by the information that is relayed on the screens which the RIVM refers to as ”cognitive load”.
Your brain just needs a little time to relax after all the stimulation that you receive if you are sitting interacting with your phone.
Another reason that the use of phones can lead to a lack of sleep is ”time displacement”: the screens are so addictive that you blindly spend longer sitting staring at your phone than you really meant to, which means you go to sleep later.
For TV viewers, the researchers found that the opposite was true: anyone watching TV just before going to bed actually seemed to get a better night’s sleep. Watching TV, they suspect, is just much more relaxing than apps – but don’t go and binge watch a cliffhanger series.