When it comes to sleep, you’ve probably heard a lot about blue light from screens having a disruptive effect. But you shouldn’t get the idea that all light is bad for sleep.
A lot of it has to do with a hormone called melatonin. Melatonin is what tells your mind and body that it’s time to sleep, and light exposure is an important way you regulate production.
The melatonin maker
The part of your brain that triggers melatonin production is called the suprachiasmatic nucleus. It sits right above where your optic nerves - the ones that carry information from our eyes - cross. Before the days of artificial lighting, the only information it would have to go on is natural light, and and the cue for the melatonin machine to start up is when that natural light starts to dim. So it kicks into gear from late afternoon and spikes around 8-9pm.
Of course, you no longer bed down as the sun sets or rise with the dawn. Lots of artificial light can make your brain act like it’s still daytime long into the evening. This is particularly true when you’re exposed to lots of the blue part of the light spectrum, which you get in spades from screens and devices. All of this combined can stop you producing the amount of melatonin you should.
There are ways to combat it though. Using ‘night shift’ settings, popping blue light filters on your devices and switching to amber-coloured mood lighting of an evening will all help. And if you can occasionally swap Netflix and Instagram for an old-school printed book, you’ll probably feel the benefit. No judgement, though.
Setting your body clock
Having said all that, it might seem like you need to avoid bright light at all times. Quite the contrary! Getting plenty of bright outdoor light when you’re supposed to - throughout the morning and early afternoon - can actually help regulate your body clock. So take your lunch break and get outside; you’ll benefit from the exercise and set yourself up for better sleep.
You can also help support your body’s production of melatonin by eating some sleep-friendly foods. Sour cherry and pomegranate juices both naturally contain melatonin and you get some handy antioxidants too. Other foods you might have heard being recommended contain an amino acid called tryptophan, which is part of the melatonin production process. That’s the list that includes turkey and chicken, seafood, dairy, eggs and pulses. And if you’ve heard of the happiness hormone serotonin, well, that actually gets turned into melatonin. So eating foods that contain it, like kiwis, could help provide a boost.