Smartphones in bed can lead to bad sleep, but it’s not because of the blue light, says Dr Michael Mosley. Photo / Getty Images
Smartphones in bed can lead to bad sleep, but it’s not because of the blue light, says Dr Michael Mosley. Photo / Getty Images
This summer we’re revisiting some of the most-listened to podcasts from across the NZ Herald network in 2024.
In April, ahead of the Daylight Saving Time changeover, The Little Things, hosted by Francesca Rudkin and Louise Ayrey, spoke to Dr Michael Mosley, author of 4 Weeks To Better Sleep about what causes insomnia, how to sleep better, and why we should get phones out of the bedroom.
This interview was recorded and published prior to Michael Mosley’s death in June 2024.
Can’t sleep? It’s a common issue that plagues many Kiwis. And the more we worry, the worse it gets.
It can get harder as we get age. “Sadly as we get older we seem to get less deep sleep,” says Dr Michael Mosley.
There are different stages to sleep, and we all go through them; deep wave sleep is when most of the important rejuvenating processes happen, particularly for your brain, he explains.
Getting that famous eight hours of deep unbroken sleep is a rarity for many Kiwis.
“Hardly anyone manages that these days,” says Mosley. “The interesting thing about sleep is there doesn’t seem to be an absolute definitive number for different people. For most of us, it’s seven to eight hours, but some people get by on much less.”
He also challenges the concept of habits changing as we get older. “There’s the idea that older people don’t need as much sleep, but the reality is that they don’t get as much sleep.”
Dr Michael Mosley is the author of 4 Weeks To Better Sleep.
Waking in the middle of the night, and starting to worry about life, is the most common form of insomnia.
If there is no definitive amount of sleep you need, how do you know if you are getting enough? The best indicator of whether you’re getting enough sleep is, he says, whether you feel refreshed when you wake up.
If you feel sleepy during the day or fall asleep on the sofa watching television, take that as a warning sign. “If you fall asleep regularly during the day and you don’t intend to, then that’s an indication that you’re simply not getting enough sleep.”
A brain cleaning happens when we sleep, which flushes toxins and helps secure our memories, and there are processes the body also goes through to maintain balance.
Poor sleep can impact everything from cortisol and libido to blood sugar. Why does that happen? “We don’t really know,” admits Mosley. “What we do know is that poor sleep has an impact on pretty much every organ in your body.”
A bad night’s sleep can make us irritable, and this is where REM sleep comes into play, in addition to that vital deep sleep. “There’s lots of evidence now that REM sleep is important for emotional regulation,” Mosley says, explaining that dreams are almost like a form of psychotherapy. “If you don’t get enough REM sleep you’re very grumpy and prone to anxiety and depression.”
Can sleep trackers help or is it better to not know? “They’re not bad and they’re getting better,” he says of a device such as a Fitbit or Apple Watch. “As long as it’s measuring your heart rate it seems to be reasonably accurate.” He finds them interesting and useful, though cautions against becoming too obsessed with the data.
They can help you understand if you’re experiencing a form of insomnia or broken sleep and whether you need to seek a diagnosis for a condition like sleep apnoea, which is critical to address. “Without sorting out sleep apnoea, nothing else counts.”
Clinical trials he’s been involved in show it’s more common than you might expect. “Two-thirds of us had some form of sleep apnoea and we didn’t know it.” While men are more likely to experience sleep apnoea, it also impacts post-menopausal women, and he says that 10-20 per cent of adults over the age of 40 likely experience the condition. “It’s massively undiagnosed.”
Another much-discussed impact on sleep quality is blue light and its impact on our circadian rhythms, with many blaming smartphones. “It’s not the blue light,” says Mosley, who debunks the myth.
The problem is what we’re doing on these devices. “It is social media that is messing with your head.”
So, putting the phone down is one thing. What other methods can help you sleep better? What should we do?
Counting sheep doesn’t work. “Try slow, deep breathing. This I’ve found really effective,” says Mosley, who recommends the 4:2:4 method, which slows your heart rate and triggers sleep.
He shares other tips for both larks and owls – early and late risers respectively – and explains why our body clocks can differ.
Diet and exercise are important for good quality rest; coffee and alcohol can have a detrimental impact, while resistance training can help.
Behavioural techniques are key. “You have to teach your brain to associate bed with sleep and sex. And nothing else.”
Our habits have caused this; with the rise in people taking their phone to bed or having a television in the room, the bed has become a place for entertainment.
“Books don’t have quite the same impact,” he says, explaining they trigger a different part of the brain to social media and TV. Reading is also a good thing to do if you can’t sleep. Mosely advises finding a quiet, dark corner to read until you feel sleepy.
He also explains how sleep restriction therapy (SRT) works to fix sleep patterns by limiting the hours spent in bed. “It’s the single best way of treating insomnia.”
Inspired? Or overwhelmed? Mosley also warns against worrying too much. “One of the dangers about banging on too much about the problems of poor sleep is that a lot of people are going to stay awake worrying about the fact that they’re not going to sleep, and that becomes a self-fulfilling prophecy.”
The Little Things is available on iHeartRadio, Apple Podcasts, Spotify or wherever you get your podcasts. The series is hosted by broadcaster Francesca Rudkin and health researcher Louise Ayrey. New episodes are available every Saturday.
