Illustration: Eleanor Shakespeare/The Guardian

The Guardian Interview with Professor Russell Foster / Saturday 15 July 2023

‘You’ll have more empathy, you’ll have more fun’: the man who wants to transform our relationship with sleep

David Shariatmadari

From snoring to shift work, Russell Foster explains the myths and misconceptions that get in the way of a well-rested society

rofessor Russell Foster CBE, head of the Sleep and Circadian Neuroscience Institute at the University of Oxford, has some relationship advice. One of the things he’s asked most often at public talks is what to do if your partner snores. First, check with your doctor if a serious condition like sleep apnoea might be to blame. Second, get some ear plugs. Third: “If you have an alternative sleeping space, then use it. It’s not a reflection of the quality of your relationship. I would say that in many cases, it’s the beginning of a better one. You’ll be more rested, you’ll be less irritated with your partner, you’ll probably have a better sense of humour, you’ll have more empathy. You’ll have more fun.”

Is he speaking from personal experience? “Perhaps … ” Who’s the snorer in his marriage? “We’ll gloss over that,” he says with a chuckle. And what about so-called chronotypes – whether you’re a lark or an owl. Can a mixed marriage work? Oh yes, he says, again drawing from personal experience (he’s an “evening type”, while his wife, Lizzie, likes to get up early). The data actually suggests that these kinds of partnerships tend to last longer. “Now my cynical colleagues say that’s because you don’t see much of each other. I prefer the explanation that if you can accommodate your partner’s sleep habits, then actually, it shows you have a reasonably flexible disposition. And then all the other crap that is thrown at you in a relationship can be [dealt with] appropriately.”

Sleep is like shoe size, and it would be crazy to suggest that everybody should wear the same size shoe

We’re speaking over a cup of tea on the sidelines of the Hay festival, where the cheerfully avuncular Foster is due to give a talk about the biological clock, the subject of his bestselling book Life Time. People flock to these events, seeking understanding but also reassurance. Part of the motivation for writing it was “this incredible anxiety about sleep”, which Foster puts down to the awesome pile-up of evidence about how intimately it is linked to our health and wellbeing.

This knowledge is useful, but it’s a double-edged sword – particularly when it’s not properly explained. For example, people tend to want a specific answer to the question of how much sleep they should be getting. “I can’t tell you because it depends upon your individual needs, how old you are, and all the rest of it,” Foster says. Before writing the book, he admits, he was “very frustrated with the sort of sergeant majors of sleep, screaming: you must get eight hours. Sleep is an immensely dynamic part of our biology. Sleep is like shoe size, and it would be crazy to suggest that everybody should wear the same size shoe.”

At the same time, he says, it’s actually pretty simple to figure out if someone’s getting the sleep they need. “Am I able to function optimally during the day? Do I feel as if I’m firing on all cylinders? Does it take me a long time to wake up? Do I feel groggy? Do I need a nap in the middle of the afternoon? Do I seem more irritable? Do I – and this is a critical one – oversleep on weekends or free days?”

While sleep tends to monopolise the Q&A session whenever Foster is in front of a crowd, it’s not his first love. He’s also the director of an ophthalmology lab, his interest in sleep a byproduct of his fascination with the eye: the organ we see with, but also the one that sets our circadian rhythms, whose effects extend into cognition, mood, immunity, reproduction, you name it. His biggest scientific achievement is the discovery that light-sensitive cells in the retina unrelated to vision synchronise us to day and night. If these are lost or damaged things can get seriously out of whack (Foster mentions a blind war veteran who found himself mowing the lawn at 3am). In some who’ve lost their sight, however, those cells are preserved, meaning that even though they have no vision, it’s still important their eyes are exposed to daylight.

For his next book, Foster plans to look even more closely at light itself – one of those things, like circadian rhythms, which he says is “so obvious, we’ve ignored it”. It sounds like a more freewheeling, esoteric work than Life Time, which was practical, stuffed with information, and occasionally a bit textbook-like. His aim is to explain the science, but also spur a sense of awe. “Just think about the formation of a photon in the centre of the Sun, which then takes a million years to get to the surface, and then six minutes to get to Earth. And what does it do?” He reels off a list of wonders: photosynthesis, the liberation of oxygen, the evolution of complex life, all the way to the creation and enjoyment of great art (Turner, naturally, is his favourite painter, and there’s a fair amount of art and philosophy in the new book).

It’s a departure, but not out of character: Foster’s natural bonhomie is at least three-quarters nerdy delight in the subjects he’s explaining, with the rest a desire to inspire the same enthusiasm in his audience. That nerdiness has deep roots. “When I was a kid I remember putting a fly in a glass tube and Sellotaping it to a turntable. I was curious to see: would it get dizzy? And then, you know, it flew off perfectly well, telling me that its balance mechanisms must be fundamentally different from the sorts of systems we use. I’ve always been fascinated with mechanisms.” He’s also extremely keen on helping people, and tells me excitedly about a drug he’s identified that could reset the clock in people who’ve become desynchronised, from the blind to those with neurodevelopmental disorders or severe mental illnesses. “If I can end my scientific career having given that sense of time to the timeless, I will die very happy indeed,” he says.

Given this altruistic streak, why didn’t he become a doctor? Two of his daughters are medical students, but he considers himself “too emotional” for it. “I could not deal with telling a mother her child’s going to go blind or something. It’s just so overwhelmingly upsetting. And that would make me a very bad doctor indeed.” Wouldn’t it make him a compassionate one? “Yeah, but you’ve got to keep your emotions under control. Somebody blubbing is not going to help anybody.” Instead he focused on fundamental science. It was only when he felt that his specialism had become mature enough for translation – in other words, ripe for practical application – that he took on his current roles at Oxford.

Sleep disruption affects our capacity for empathy. Divorce rates among night workers are six times higher

Those applications range from the relatively narrow – that drug to kickstart the clock, for example – to the mind-bogglingly broad, including changes to the way we work and even the structure of the family. Indeed, the circadian science Foster has made it his mission to explain to the world suggests a far-reaching political programme, as well as a self-help one.

Take shift work, for example. Being awake at night has all sorts of horrible effects on our physiology, making us active when we’re supposed to be in rest and repair mode. The long-term consequences can be dire, from diabetes to cardiovascular disease and cancer. Sleep disruption even affects our capacity for empathy, one explanation for the fact that divorce rates among night workers are apparently six times higher than the norm.

That’s important to know, but what are people supposed to do about it if that’s the only way they can earn a living? “There’s a duty of care from an employer to the employee,” Foster says. Companies should provide extra health checks, nutritious food and transport home (in the US, an estimated 100,000 car crashes are caused by drowsy driving every year). They should offer extended breaks from night work – maybe five years on, five years off. Surely businesses aren’t going to volunteer to do this stuff, though? “I think it’s going to come to the point where people will start to bring class action suits,” he says. “They’re going to say: ‘Look, just read the scientific literature.’ There’s a hell of a lot out there.”

He predicts a gradual change in attitudes, along the lines of smoking. Education will be an important part of this, although he’s frustrated that the findings he’s made in that area haven’t been more widely applied. Foster ran a pilot study for schools involving eight 30-minute lessons about sleep circadian rhythms. “Before [the lessons], about 20% of kids were showing levels of insomnia that would probably be clinically relevant. Afterwards, the average went out of the danger zone.”

But they quickly discovered teaching wasn’t the only intervention needed. “We asked a bunch of questions, one of which was, do you share your sleeping space with anybody else – expecting that yes, bedrooms would be shared as kids. We didn’t ask the question: do you have a bed? And it became clear that many didn’t. Their bed was the family sofa. So that quality of sleep was really poor, and they would start school the next day chronically sleep deprived.” It’s a vicious cycle: poverty affects sleep, which affects education, which in turn affects life chances. One study in America saw outcomes improve when children were given good pillows, but it’s clear this is about more than just bedding. “It’s the poorest sectors of society that are clobbered the hardest. And so we need to be more kind and generous to that group of individuals. Perhaps I’m being somewhat naive – but I don’t see anything wrong with trying to protect the most vulnerable.”

One area where poor sleep is surely just par for the course is parenthood, right? Well, not necessarily. “All primates have extended childcare,” says Foster, with family members sharing the burden and allowing parents to catch up on sleep. “We’ve had a complete loss of this, so childcare is now on the shoulders of just the parents, and usually just the mother. And that’s not fair: we’ve not evolved to do that. So first of all, you shouldn’t feel guilty that you’re not coping, because you’re tired. We should introduce extended care wherever possible, with friends and families playing a greater part.”

No stage of life is untouched by sleep, so no area of policy is, either. For example, elderly people in residential care get much less access to natural light than the rest of us. As a result “the sleep-wake system begins to slide and you get all the problems associated with that”. Foster cites a “wonderful study from the Netherlands” where an increase in the amount of light in the nursing home boosted levels of cognition by 9-10%.

Does he appreciate that there are quite big political implications to some of these findings? “I haven’t really thought about it in those ways. It’s really been more: what’s the problem? This is what I think we should do. But you’re quite right. It does have a major impact across many sectors of society.”

And ways you might never have imagined, too. Did sleep deprivation nearly bring down the world economy? “I think the banking sector has been the classic one for me, you know, the crash of 2008. You had a bunch of jocks, chronically sleep deprived. And what we do know on the basis of the science is that [this creates] overly impulsive, non-reflective behaviours. And that’s not what we need. We need a society that can be empathetic and make the appropriate judgments. And what we know is that sleep can enormously enhance our capacity to do that.”

What would a better rested society look like? “I would hope it’s a kinder, more reflective, more constructive, more intelligent society … We’re so incredibly arrogant. We think we can do whatever we like, whatever time we choose, and can ignore 200 million years of evolutionary baggage. Think of Shakespeare – ‘O gentle sleep, nature’s soft nurse, how have I frighted thee’ – he knew intuitively the power of sleep. Yes, we have been able to achieve a huge amount, but we’ve got to get the balance right.”

If you are interested in the Network, please contact Professor Sally Shuttleworth (sally.shuttleworth@st-annes.ox.ac.uk)

Find out more about the Sleep and the Rhythms of Life Network here.