Sleep Eazzzy with HIF

What if … you could get a better night’s sleep?

Welcome to Sleep Eazzzy with HIF, the podcast dreams are made of.

Join hosts Guy Rowlison, Kelly Petering and our expert guests, as they challenge myths and misconceptions about sleep, identify determining factors that are hindering people from getting a decent night’s shut eye and provide practical tips on how to catch those elusive zzzs.

We know there are a lot of podcasts out there focussed on helping you actually fall asleep.

What we hope is to provide such stimulating conversation, you’ll be awake just long enough to learn a thing or two about sleep and how to improve your bedtime routine.

Whether you struggle with sleep issues or simply want to learn more about why sleep is so important, the Sleep Eazzzy with HIF podcast is here to help.

So, you can make sleep your superpower.

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Sleep Eazzzy with HIF

Step Into The Light

November 13, 2024 • HIF Health Insurance • Season 1 • Episode 3

There’s a common belief that screens that emit blue light make it harder for us to fall asleep. But is that really the case?

We speak with sleep scientist and sleep practitioner Dr Michael Gradisar, on the effects of using screens on sleep … and whether or not you need to take that TV out of your bedroom.

Dr Gradisar is a Professor of Psychology and Clinical Psychologist at the Child & Adolescent Sleep Clinic at Flinders University, Adelaide, Australia.

He has published over 120 scientific studies, book chapters and books, including publications investigating the effects of screen light before bedtime and is one of the leading researchers into the links between technology use and sleep, as well as treatments for young people.

To find out more about how a better night's sleep can assist your overall health and wellbeing visit www.sleep.hif.com.au

There's a common belief that screens which emit blue light make it harder for us to fall asleep. But is that really the case? Today we speak with sleep science practitioner, uh, Dr. Michael Gratisar on the effects of using screens when it comes to sleep and whether or not you need to take that tv or iPad out of the bedroom. Dr. Gratisar, uh, is a professor, director, uh, and clinical psychologist at the Child and adolescent sleep clinic at Wink sleep in Australia and the head of sleep science at Sleep Cycle in Sweden. Michael, welcome to the show.

Speaker B

Thanks for having me, guy.

Sleep and blue light have gained prominence in recent times

Speaker A

If I could start out by exploring the basics of sleep and blue light. To start, uh, let's break down the fundamentals for listeners who might be new to the topic and explain the connection between sleep and exposure to blue light and why this relationship has gained such prominence in recent times.

Speaker B

Yeah, that's actually been fascinating for me because, I mean, I started, • uh, working in sleep in 1998, uh, both in a research capacity, but then a few years later, I started working as a clinical psychologist, helping people with insomnia, but also helping people that have what's known as a circadian rhythm disorder. And some people have heard now of circadian rhythms, but we would commonly say it's a body clock issue. So, for example, people are fairly familiar with teenagers who seem to be hard to get out of bed. Well, that's because of a body clock issue. They're falling asleep late. Their body is telling them to fall asleep late. They also want to wake up late. That's what their body is saying. That's a circadian rhythm issue. But even it can happen as we age. So, say, for example, older adults are more likely to have a body clock issue in the other direction where they're sort of struggling to stay awake after dinner, and then they might be waking up at 04:00 in the morning and can't get back to sleep.

Um, and what's really been learned over the last 20 or so years is that when it comes to our circadian rhythms, that the most powerful tool that we can use to try to change the timing of our circadian rhythm is light and light signals. And, of course, light goes through the eyes. And so we've known that and done a lot of science collectively, uh, as sleep scientists over the years, and it's found its way into things like bright light therapy, which we can talk about later and so forth, because I think it's really important.

Um, and then probably in terms of why it's so prominent these days, I think it's just been fascinating watching the evolution of sleep and the way that it's been translated and into the community. Um, sure enough, we've had social media, I guess, for quite some time now, but maybe if you look back at, say, for example, 2007, I think that's when really the Fitbit became prominent and that's when you really had a number of people starting to go, hey, look at this, my watch is telling me how much I slept. And then gradually over time, you've had all of these different sort of sleep gadgets and people are starting to become more aware of and interested in their own sleep. And probably what I've seen over the last several years is what I've called the rise of the sleep coaches. I mean, coaching in general has now really sort of taken a lot of prominence. People are sort of not necessarily going through the usual sort of health professional qualifications. They're learning how to sort of do these different techniques and there is a place for it because a lot of people need help.

Uh, but, uh, now we see a lot of sleep coaches and I guess the one limitation of that training is really what a lot of health professionals go through, which is being able to accurately analyse and interpret scientific studies and therefore translating that to the community in an accurate way. And I think now that we've got the combination of a lot of people that I say pretty, uh, much are now driving in the sleep lane, um, whether they're a sleep coach that doesn't necessarily have a background in the health profession, or even if they're a prominent researcher with millions of subscribers on YouTube, we're still getting a lot of these people that are, uh, not necessarily translating the science about light, circadian rhythms and sleep.

Concerns about blue light from screens before bedtime are widespread

Speaker A

So let's address a few of the concerns about blue light before bed. The, uh, conversation surrounding the adverse effects of blue light, especially from screens before bedtime, is pretty well widespread. Could you provide a bit of an insight into whether these concerns are, uh, well founded?

Speaker B

Um, I will say the answer first and then go into it, but no, they're not founded. Now, there's two aspects of light that your listeners really need to understand. One is about colour, so we're talking about blue light. Um, and when you think about the different colours of light, that's really the colours of the rainbow. It's really about, uh, looking at the blues, the greens, which are the most powerful in terms of increasing alertness, which is obviously the opposite of sleep. And they're also quite powerful in changing the timing of the circadian rhythm uh, so, for example, using something like blue, uh, light should be more effective than, say, yellow and red light. But probably what's much, much more important than that is the brightness of the light. So if you have dim blue light, it's not necessarily going to have an effect on your alertness levels and your sleep and your circadian rhythms. But say, for example, if you have very bright red light, believe it or not, that will change your circadian rhythms. It will have an effect potentially on your sleep. But a lot of people don't necessarily know about that. So that's really the background people have to understand. Brightness of light is much more important than the colour of light.

And when we're talking about screens, we've sort of gone from like, if you think about tvs, you've got what's called those big boxy tvs that I guess we used to have, those cathode ray tubes, crts. Um, now what we've got is really sort of like the prominence of these led screens, whether they're sort of like a phone or a computer, laptop or anything like that. And what happens is that they do emit light like the colours of the rainbow, but they emit a fair bit of blue light compared to all the other, uh, different colours. So I guess because of that, a lot of people have rang alarm bells and said, oh, wow, they're emitting all of this blue light. Blue light is bad for sleep, but they've forgotten the crucial factor, that it has to be bright. And we were the first group, the research group in the world, to actually test whether the blue light coming from screens is actually bad for your sleep. And we published that in 2014, luckily, because we showed that it doesn't actually make it difficult to fall asleep if you have a bright, in this example, iPad in your face in the hour before bed. So really, um, since then, there's been a lot of studies that have repeated our, uh, experiment in a similar sort of fashion, whether it's an iPhone or a computer and so forth. And they've really confirmed our results, uh, to really sort of show it doesn't make it difficult to fall asleep.

Blue light from screens can affect your sleep, studies have shown

Speaker A

Which leads me to the blue light blocking glasses. Uh, we would have all heard about them by now, whether it's late night tv or online or reading.

Speaker B

So are they all that they're cracked up to be?

Up to be or is it just hype?

Speaker B

Well, really, as they're sold, they're supposed to block blue lights. Now, what people have to understand is that they vary in the amount that they can block. They won't block 100% of all blue lights. And blue light isn't just blue light. Categorically, it's along a spectrum. Uh, so there is even, like, green light that can be quite potent. Say, for example, if it's bright enough, but you'll have certain glasses that don't block those green rays of light. So when we did our first study, not only were we testing the impact of a bright iPad in people's face in the hour before bed, but we also, at that time prior to apple, inventing, uh, night shift mode, which actually reduces the blue light and gives that orangey glow from the, uh, screens, there was this, uh, app called f Lux that was available, um, and at the time, Apple weren't including it on their iPads. So we actually had to jailbreak these iPads so we could actually install this third party, um, software. So we were also testing whether if you decrease the blue light coming from these screens, does it improve your sleep? Now, when we had the bright light condition, full brightness, white screen for an hour, we struggled to stuff up people's sleep. And that's exactly what's been shown. Study after, uh, study after study. Probably the most talked about and promoted study was a study that came out the following year by Harvard University. So, of course, it got a lot of publicity, and it was really unfortunate because, yes, they found statistically that it took longer to fall asleep after reading on an ereader compared to a printed book. But they didn't really promote how much longer? And it took nine minutes longer.

Speaker B

And most people know that nine minutes longer to fall asleep, that doesn't really matter yet. It got so much attention when it came out. And then probably what happened after that to really ramp up what I now call this big sleep myth, is that, uh, Dr. Matthew Walker, who's an excellent sleep scientist over in, uh, the University of California, he wrote a book called why we sleep. And that was published, uh, in 2017. And it really covered a lot of different topics. And when it came to screens, it also talked about the blue light from screens. And to prove that point, he spoke about this Harvard study. And the Harvard study was great. Just the interpretation of that study to the population wasn't so great.

Uh, from there on, you saw things like, uh, I don't know if it was the following year in 2018 or 2019, that Bill Gates around Christmas time was sort of talking about his top five books for Christmas time and why we sleep was in there. So it just got this massive promotion. And then Matthew Walker did all of these huge YouTube interviews with the likes of, um, Andrew Huberman and, uh, Joe Rogan. He's had it with the diary of the CEO, uh, Stephen Bartlett as well. And so there was a lot of promotion about this concept. So again, the amplification of this idea that blue light from screens affected your sleep was really getting out there. It was like a tsunami, really, of, uh, this sort of information. But I, uh, have to really seriously add to, uh, Dr. Matthew Walker's credit. He has since, uh, looked more broadly at this topic and realised that, hey, if we look at all of these different studies and put them all together, it's very fascinating because the Harvard study is the one that showed it took longer to fall asleep by nine minutes. Other studies have shown it's actually people have fallen asleep faster when they've got this bright screen in front of their face compared to a book. For example, there was a study that was done in Norway in 2016. So, um, Matt, to his credit, has come out, uh, like, say, for example, in the diary of CEO podcast, to say, essentially he's changed his mind about this topic when it comes to the blue light, uh, affecting our sleep.

Speaker A

Sure.

Timing of light exposure is crucial to optimising sleep cycles

Sure look similar to jet lag. Uh, the impacts of shift work can be, uh, significant. So what measures can individuals adopt, uh, to address sleep related issues arising from that? Dreaded rotational roster syndrome.

Speaker B

Yeah, and this is the trickiest one of all because, • um, at least when it comes to say, uh, for example, we've talked about teenagers and their body clocks.

We know when they should get light and that we know that all other variables, so to speak, are consistent. Um, when we talk about jet, uh, lag, we know this is where we're coming from, this is where we're going. Things are reasonably predictable when it comes to shift work. It is the most trickiest thing because things are changing all the time.

Um, the first thing to understand is for the majority of the population, especially, uh, if you're in finger quotes, young. So say, for example, if you're somewhere between being a teenager to being in your 30s, um, most of us find it easier to delay our circadian rhythms, which means that in terms of your roster and a rotating shift work roster, having rosters that gradually shift from later to later to later works better for us as opposed to the other direction. So in other words, if you go from days to afternoons. I went to say arvos, typical australian slang.

Uh, basically, if you go from days, afternoons, evenings, nights, that's the better direction than going nights, afternoons and days. And what's even worse is if you're sort of just mixing all of those around.

Uh, it's also pretty key that your organisation is giving you enough days in a row off so that you can try to not only recover from what your body has just done, but also try to get ready for the next set of shifts. Uh, if you look even at some of the research that's typically looked again, we'll use adolescence as an example because they're a really interesting, dare I say, model to look at two weekends. I should say two weekend days are, uh, not enough to recover from the five days of sleep restriction that they go through each school week. Even one study in Singapore, I think they tested if we had a three day weekend after having five days in a row of restriction, uh, and that was not necessarily getting them back to baseline. So you would hope that, uh, a roster also includes at least three days off in a row to be able to sort of recover and reset, uh, to try to prepare for the next set of rotating rosters. So if you are on a delaying roster and it's going later and later again, it's the same sort of principles that we just talked about when travelling Westwood.

Uh, =you need to basically use light to be able to have it later, expose your eyes to it later so you can shift your body clock later as you're going through these rotations. Now, if you're the poor bugger that has essentially got it going in the other direction now that might favour like a 50 year old. I mean, I've just turned 50 and I'm finding that as much as I've been a night owl all my life, um, I'm finding it easier to wake up in the morning. Uh, so this is what naturally happens as we develop.

But say, for example, if you're a 50 year old doing shift work, you might actually find it easier than the average person to go from lates to afternoons to days. Um, nevertheless, if you're going earlier, then believe it or not, what you need to do is get light earlier in the day and earlier and earlier as possible in your day, so to speak, with finger quotes.

So we can actually manipulate the direction of our circadian rhythms and therefore our sleep depending upon when we get light. So if you want to delay your rhythm, you need to get light in the evening. If you want to advance your rhythm and make it earlier, you need to get bright early in your day in the morning.

Speaker A

Let's wrap up with the pros and cons of sleep related apps now. Ah, the proliferation of sleep related apps. It's crucial to understand their impact. Firstly, what are the pros and cons of using these apps and their potential influence on our sleep patterns?

Speaker B

Yeah, and listeners should know that I work for a sleep app company called Sleep Cycle. So they've been in existence since 2009. Their focus hasn't necessarily been purely on what's called sleep tracking and measuring your sleep, but more so on what's called, uh, their smart alarm, which means that because they use an audio signal to be able to determine when you are somewhat asleep versus somewhat awake, these, ah, are estimates. Um, what will happen is if the person who uses the app sets an alarm, not necessarily for a specific time, but say, for a window of time, like, say, for example, 15 minutes.

If you want to wake up somewhere between seven M-A-M and 715, what the app will do is it will wait until it hears enough movement because it is actually sensitive enough to detect when your body is moving across the sheets and so forth. It can also listen to breathing patterns, and when it senses that you are much more towards the waking sort of side of your sleep, that's when it will set the alarm off.

So it could be 708. So that way people aren't necessarily woken up out of sort of a deeper stage of sleep just because it's that particular time. And I would have to say that the success of the company going from 2009 till now, most of our users, uh, and our user base, our customers, they actually use it for that particular function. And that's what's probably helped drive its success.

So people have to sort of understand, when it comes to a sleep app, what do they want from it? Most wearables will have an app that goes with it. If people are interested in their sort of REM sleep or their deep sleep, they can have a look at these. Some of them are scientifically and independently validated versus other ones. Um, but if people want to wake up feeling better, then they might go to something like sleep cycle or dare I say, one of those apps that's copied us as well.

But, um, there are also other apps that if people are looking to improve their sleep, um, and certainly I would say in terms of AI and AI, it's not as bad, I think, as what people are sort of talking about at this sort of point in time. I've tested AI when it comes to some of the stuff in sleep, and it's way behind us at the moment.

So, uh, I think there is much less to be afraid of. But when it comes to probably the most common therapy for insomnia, which is called cognitive behaviour therapy for insomnia, I would have to say that, uh, something like sleepio has a lot of scientific studies behind it. It's created by one of the world's best sleep and insomnia experts in the world, professor Colin Espy. Uh, and so that's an example where if you're looking for an improvement, you can't sort of get to see someone, uh, one on one. You've got those barriers, then something like that has a lot of validation behind it. It's been shown in a number of different ways, not only to improve the individual's sleep, but even a company's, uh, sleep and their bottom line, for example.

So it really just depends upon what people are after. And I think I'm hoping that that's a different answer for the listeners because I think the stock standard thing is that people will look at their sleep and then they'll start to get anxious. And there's this thing called orthosomnia. Now, people probably don't understand that this concept of orthosomnia, uh, it came about in the research literature in about 2017. There's been three studies on it, and it hasn't really been shown to be a big thing yet. If you google it, you'll get massive amount of hits.

So really, sometimes, uh, people, unfortunately, uh, are sort of hearing things as we've just even talked about when it comes to blue light from screens, they're hearing this commonality, this popular sort of beliefs, and that can be okay for people to hear that, but I hope that they sort of switch on their sort of fact checking. And sort of one way to do that is to go to something called Google scholar. If you type into Google, Google scholar, you'll then suddenly have a different sort of search engine that will pick up, uh, research studies.

I understand people find it hard to read research studies because they can be quite technical. But if you're looking for a particular topic and you type in the word review, then suddenly it reduces the amount of jargon and makes it easier to read. So that's one way that people can start to sort of fact cheque some of these ideas around sleep or anything else. They're interested in.

Speaker A

Well, we've managed in a very short amount of time to navigate the impact of natural sunlight through the nuances of artificial lighting, the relationship between light and our circadian rhythms. But if there's more listeners would like to know, is there anywhere in particular you would point them to as far as informed information?

Speaker B

Yeah, well, certainly, um, it's always important to look at sort of more official websites. So say, for example, in Australia we've got the sleep, uh, health foundation. Um, they've really been driven as a purpose to really educate, uh, Australians about sleep and to do that as accurately as possible.

And they do actually get, uh, sleep experts, dare I say, true sleep experts. I'm sure I'm going to offend a lot of people that don't like that term, but, uh, these are health professionals that have done the qualifications that have worked in this area, like myself, for a decade or two, uh, to be able to provide information that is directly from the science. Um, uh, unfortunately, there are things like, I think a lot of people are probably now, uh, enjoying.

They're enjoying podcasts, they're enjoying YouTube videos as an example. Um, and I don't know if this will make it to the cutting floor or not, but you've got someone who's incredibly popular, Dr. Uh, Andrew Huberman. Um, he's actually an expert when it comes to, uh, ophthalmology. Uh, but he's sort of dancing and driving in different lanes, including sleep and light. Uh, and he's actually sort of coming out a fair bit with some light sort of stuff.

And probably two thirds of it's correct. It's actually not his field. So he's getting some of it right, but some of it's not right. Um, so that really makes it confusing for, I think, listeners to sort of go, well, where do I go for this? So, um, I would say as a first sweep, you'll hear something.

If you're interested, go to a more official sort of website. Um, but hopefully that sort of hint about fact checking for yourself. Say, for example, if you were interested to sort of read more about this concept of blue light from screens and sleep, just, uh, type the, know those words, blue light, screen, sleep, and then the word review into Google scholar. And hopefully you'll start to read stuff that you can start to digest, understand and get it from the source.

Speaker A

Dr. Michael Gratisa, uh, once again, thank you for your time and your insight nights and for joining us today, um, on sleep easy with hif.

Speaker B

Thanks, guys, it's been a pleasure.