Dr Amy Reynolds in a sleep scientist at Australia's Sleep Health Foundation. She works with large data sets, sometimes drawing from thousands of people, to better understand how our work schedules, sleep and overall health are interrelated.
VICE: What do you consider to be the next frontier in sleep science?
Dr Amy Reynolds: There's a lot of really novel research going on. I would like to think (and hope) that the next frontier is an attitudinal shift in how we as a society think about, and prioritise, sleep. Sleep is a powerful tool we can use to our advantage, there is no weakness in wanting or needing to get enough sleep each night, and I’d like to see this accepted more broadly. I think there has been a bit of a historical attitude that getting little or no sleep is a badge of honour, or an indicator that you're committed to other aspects of your life, like working late. I think this is far from true, and would like to see an emphasis placed on sleeping to perform well and live healthily.
What are some interesting beliefs about sleep from history?
The one that stands out to me was the perception that "nothing happens" when we sleep. We know now that this is not the case. So much happens in your brain and body when you're asleep. With every year, we add to this knowledge and understanding.
Is it true that we still don’t fully understand why we sleep? What accounts for this elusiveness?
There's still a lot to understand about why we sleep, yes. For example, last year we learned that people have different sensitivity to light, which can affect our ability to fall asleep at night, and that a particularly stage of sleep—slow-wave sleep—is associated with cerebrospinal fluid levels in the brain, which is thought to be there to help clear out waste from the brain.
I think one of the challenges with understanding the impact of sleep on our health and wellbeing is that there are so many factors at play. Our bodies are physiologically influenced by pressure to sleep: when we’ve been awake for a long time, and also by the time of day. But our behaviour also influences our sleep habits and activities. For example, different people use technology differently at night, which can impact our sleep. When we work impacts our sleep opportunities, too; shift workers are often trying to sleep at times of the day which aren't ideal for their bodies. Add in that the food we eat, when we eat it, and how physically active we are can also affect our sleepiness, and it’s pretty clear that not only is sleep important, it's also complex and different from person to person.
What's your favourite book or film featuring sleep as a major character?
The Sleep Book by Dr Seuss, because it’s gorgeous and I have small kids who love it. It always gets a laugh at bedtime.
Do you ever get insomnia from thinking about and analysing sleep so much?
Personally, no. My biggest challenge, like many, is making sure my behaviour doesn’t influence my sleep. Because of this, I try to be strict about technology before bed, caffeine consumption after lunch time, and making time to unwind before I sleep. I keep the lights throughout my house really dim after sunset to try to simulate night. But some people do have trouble with the big focus on the "negative" consequences of [lack of] sleep, and that's something we have to be really mindful of. It's a fine balance: the community needs to know the consequences of not getting enough sleep, but we have to be mindful that this advice may not be helpful to everyone.
What is something very few people know about sleep?
Sleep (and wake) is controlled by a master "clock" in our brain. This clock co-ordinates not just sleep, but our bodies more broadly: hormones, our body temperature, and even our metabolism. We have little clocks all the way through our bodies—in cells, in tissues, in our organs—which regulate the body and keeps it in sync with day and night more broadly. That master clock takes information from around us; like light, eating and activity; to help keep in time. This is why some of our behaviour, and the light that we're exposed to, can influence when we sleep.
What is the single most effective action someone can take for insomnia?
From an intervention perspective, we know from research that cognitive behaviour therapy for insomnia (CBTi) is the "gold standard" treatment. That is, it's shown the most benefit to patients with insomnia. Working with a sleep psychologist is an excellent starting point for individuals living with insomnia.
Can you confirm the best length of time for a nap, and the best time of day?
This is actually a more complex question than you may think. Lots of factors need to be considered with napping. There is a great fact sheet about napping available through the Sleep Health Foundation which covers these factors. Importantly, if you need to be functioning and focussed when you wake from your nap [i.e. you have an important meeting to attend], be aware of the potential for that groggy feeling when you wake; it's called sleep inertia, and may affect your ability to respond at your best immediately after you get up from your nap.
Why is it harder to fall asleep at night when you’ve napped in the day—even when that nap was short?
Because one of the two processes involved in promoting sleep builds up with the time you are awake. What can happen when you have a nap is that you reduce that pressure, or need, for sleep. This can make it a little trickier to fall asleep again at night for some people.
What's something about sleep you want to know more about?
I’d like to know more about how the timing of our sleep, and the variability in when we sleep, affects our health throughout our lives. I think the public hear a lot about how the duration and quality of sleep is important (it is), but I'm also interested in when we sleep and how that impacts our sleep. For example, are we healthier in the long run if our sleep timings are consistent each day? What's the impact if our sleep is always all over the place—sometimes late at night, sometimes early? I’d also like to see sleep used positively as a tool to support patients in hospital, and living with chronic illness in the community. Sleep is not discussed as commonly as it could be.