“I’m convinced we’re sleep-walking into a sleep crisis. So many of us are waking up feeling ghastly in the morning,” says Dr Michael Mosley, who knows first-hand just how bad not getting enough sleep can be: he battled insomnia for more than 20 years.
It wasn’t always the way. When he appeared on Insight’s Sleep Hacks episode last year, he confessed that in his younger, wilder days he slept in a bath, a telephone booth and graveyard!
But then life happened – medical training, children, a busy job – and good sleep disappeared. His decades of searching for better sleep led Mosley to write a book, Fast Asleep, and make a documentary called Truth about Sleep, in which he explores what sleep is, what happens when we don't get enough, and what might help us sleep better.
Mosley is not alone in his battle for good sleep. Research by Australia’s Sleep Health Foundation in 2019 found more than half of all Australian adults are regularly suffering from sleep problems such as trouble falling asleep or waking up in the middle of the night.
One of the things that experts tell us can make a big difference to sleep quantity and quality is our pre-sleep routine. On the list are getting to bed at the same time each night, avoiding alcohol and caffeine, not eating too close to bed, and avoiding activities that are stimulating in the hour or so before sleep. So does that mean no social media, no computers, no reading on a tablet, no TV?
Not exactly. While many of us will have heard that staring at bright screens too close to bedtime can affect our sleep, because of the effect of the light, it turns out that what we are watching, reading or playing may be just as important. It can tempt us to stay up too late, or leave us too unsettled to sleep.
“Firstly there is the content of what we see on the screen. The content is usually engaging and so this encourages us to continue watching. Sleep is displaced by screen viewing. Secondly, the content can be engaged in a negative way. Negative content can make us fearful, frightened, scared, anxious and worse,” says South Australia’s Professor Sarah Blunden, a Professor of Clinical Psychology and sleep researcher with CQUniversity who also runs a clinic specialising in children’s sleep problems. "As we lie in bed waiting for sleep, when our minds are otherwise disengaged there is more room for these negative feelings, emotions, and images to overwhelm us … so avoiding what triggers them is a good idea.”
It’s not all bad news – Australia's Sleep Health Foundation says that while phones and electronic games might be too stimulating, watching a pleasant TV program might help (perhaps something like the chilled-out documentary series A World of Calm?). And Professor Blunden is a realist – screens are part of our lives, she says; it’s how and when we use them that matters when it comes to sleep.
We’ll come back to how screens and sleep, but first, why does sleep matter so much?
We all need sleep
Not getting enough sleep can cause more just tiredness. It affects mood, decision making, even how hungry we are. If you’ve ever had a few nights of bad sleep and found yourself wanting sugary carbs, you’re not imaging that effect.
“We know that it [being sleep deprived] alters your appetite hormones, so it makes you more likely to feel hungry. You’re less likely to feel full. We also know that the people crave very sweet, very high carbohydrate content foods,” explains one of the experts Mosley meets in Truth About Sleep, Dr Eleanor Scott. “Also, if you’re awake when you’re not meant to be, when that’s actually quite stressful to our bodies. And we know that you produce more of the stress hormone cortisol and that can influence your glucose levels as well, the next day,” says the Leeds University professor.
A ongoing lack of sleep can also increase our risk of obesity, diabetes and cardiovascular disease.
If you're wondering if you're getting enough sleep, you can try the spoon test.
What should happen when we sleep?
Good sleep isn’t just about getting enough – the quality of our sleep matters too,
Sleep happens in cycles of around 90 minutes. In each cycle, we experience three main types of sleep: light sleep, an extended period of deep sleep, also known as slow-wave sleep, when we’re very hard to wake (but our body is hard at work doing important repair work, and our brains are getting a bit of a clean-up and working on memory storage) and REM sleep. REM stands for rapid eye movement, and in this stage your eyes are often flickering side to side; there’s more memory sorting happening and it’s also the stage where we have our most vivid dreams.
We usually get more deep sleep before midnight, which is partly why staying up too late can affect our sleep quality and how we feel when we wake up.
Why can’t I sleep?
We’ve heard a lot about the obvious things that can affect sleep – stress, too much caffeine, a body clock that’s out of whack. But apparently, science suggests our genes play a role too. In Truth About Sleep, Mosley discovers there’s been research into genetic markers that affect sleep. Sleep researcher Professor Simon Archer tells Mosley DNA analysis of his blood suggests he’s more likely to be a morning person, that he might need more sleep than the average person (“Yep, I get really really grumpy when my sleep is cut,” comments Mosley. Many of us can probably relate…) and that he could be especially prone to insomnia when stressed. He might also be more sensitive to the effects of caffeine than he thought.
“Even without knowing what your own genes are telling you, caffeine really isn’t a good idea if you struggle with sleep," Mosley says. "And there’s another drink that isn’t great either. Alcohol. Many people use alcohol to help them get off into the land of nod, but the truth is, it can cause interrupted sleep and sleep quality will be poor.”
According to Australia’s Sleep Foundation, factors that often negatively affect sleep include shift work, eating and drinking too close to bed, stress, not winding down properly before bed, pregnancy, the side effects of various drugs, sleep medications and yes, technology and bright screens.
The tech effect
Our pre-bed screen habits can affect our sleep in three main ways: the bright light can make us more alert (the Sleep Health Foundation notes research suggesting there’s less of an impact if computer and phone time is kept to an hour or less in the evening); the content can be stimulating or upsetting; or we can be tempted to stay up later, cutting into our sleep time.
On the other hand, some people may find watching television helps them wind down.
To make your screen your friend, opt for passive rather than interactive, and calming rather than upsetting.
“There is a difference between interactive screen use such as games or social media and just watching something passively. One of the main aims in the development of interactive games is to keep people engaged so that is very hard to stop. Indeed many games have reward systems in place that tap into the same neural circuitry that encourages us to gamble. So they can be very addictive,” says Professor Blunden.
“We need to ask ourselves what our priorities are. If we find ourselves thinking we are engaging too much on screens, the next question might be, is it necessary? And if so, how necessary ? If we are feeling tired in the morning, can we gain an extra 15- 20 minutes sleep?
“We have a choice to disengage from our screens in varying degrees. I find some mindfulness, and consciously setting aside time to be without my screen, or do something else, is something I have to do because in busy lives we can always justify needing to be on line all the time.”
“Sleep has historically always been displaced for other things we do which we deem more important. Sleep is the foundation of good mental and physical health. Screens need to be part of our lives, and like everything in our lives can be structured and have a timetable and balanced so that sleep is not displaced by screens.”
Mosley's advice on the tech front is to take technology out of the bedroom, and ditch emails and social media well before bedtime. "At least an hour before bed, switch off all social media. That way, by the time you go to bed, you’ll be ready for sleep."
Searching for better sleep? Watch Michael Mosley: Truth About Sleep 8.30pm Thursday 4 February on SBS and then on SBS On Demand. The Sleep Health Foundation has a wide range of Fact Sheets on various aspects of improving sleep.
Or watch Sleep Hacks, now streaming at SBS On Demand: