Professor Sleep and the Immutable Body Clock

An interview with Russell Foster

At a dinner at an Oxford college a few months ago I was telling my neighbour about my battle against insomnia and my interest in finding out more about the subject, from a professional as well as a personal point of view. He told me he knew just the man to help me - another fellow of the college was actually the Oxford Professor of Sleep.

A likely story, I thought, draining a glass of port and a coffee and munching one more chocolate truffle before tottering off to another broken night in which I barely got four hours sleep. Come on, Oxford may have professors of everything from Artificial Intelligence to Ancient Greek but surely sleep was not a subject worthy of a Chair?

How wrong I was. It turns out that sleep, how it works, and what happens when we are deprived of it, is an area where science is making big advances and Oxford’s Professor Russell Foster is one of the world’s leading authorities.

His title is in fact Professor of Circadian Neuroscience and his work has been all about showing the vital role played in every aspect of our physical and mental health by circadian rhythms - our internal body clock. His new book Life Time:The New Science of the Body Clock and How It Can Revolutionise Your Sleep and Health is an enthralling combination of scholarly treatise, personal memoir and layman’s guide to living and sleeping better.

I learned a lot from the book, not least that my Oxford dinner of rich food, alcohol and coffee was a recipe for a bad night’s sleep. A chapter on metabolism quotes a 12th century sage -”Eat like a King in the morning, a prince in the morning, and a peasant at dinner.” But Professor Foster says all sorts of factors have pushed the major sugar-rich meal of the day to the mid to late evening: “If you were designing a schedule to be particularly bad for our circadian regulated metabolism this would be it.”

When we met on a video call, his passion for his science and his mission to get politicians and the public to take seriously its implications shone through. Here are some extracts from our conversation.

Explain why circadian rhythms are so important.

Circadian systems are embedded within every aspect of our biology, whether it be an immune function, whether it be metabolism, whether it be memory consolidation, processing of information, it's all being modulated by this internal clock.

You had this big breakthrough, which kind of proved how tied up we were with light by finding this other kind of light monitor within the body. It involved an experiment with blind mice. Tell us about that.

What the Circadian system needs is an overall measure of the amount of light in the environment at dawn and dusk over long periods of time, and I couldn't see how the visual system, which was a sort of a ‘grab and forget’ sensory system could also measure light intensity for the clock.

We started with very simple experiments, using mice with hereditary retinal disorders. They had lost their visual cells, their rods and cones, and we then looked at their ability to regulate their clock by light, and it was unaffected. It was quite breathtaking, these animals with visual blindness but no diminished capacity to regulate their clocks by light

And you got some pushback at a conference in the United States?

I said these animals are visually blind, but not clock blind, and our tentative conclusion is that there's a third photoreceptor within the eye different from the visual cells, the rods and cones. Somebody stood up and shouted ‘Bullshit!”

You talk a lot in the book about something called SCRD - Sleep and Circadian Rhythm Disruption - and its damaging effects. Explain why it’s so important

We have, as a society, tended to marginalise sleep. The 80s perhaps was the low point when people would come in and say ‘I did another all nighter.’ Well, you know, well done - you're vanquishing this illness that needs a cure, sleep. But what's happened of course since since the 80s, primarily over the past 20 years, has been the realisation of the importance of sleep and, if you don't get it, what are the consequences.

We can think of the consequences of poor sleeping in three domains. One is our emotional responses, another would be cognitive responses, and the third would be our long term physiological and behavioural health.

You mention MPs at one point in the book - might they have more empathy if they had better sleep?

I think that's right, they'd also be less impulsive, they'd less be inclined to take risks. There's one beautiful study showing that the tired brain has what's called a negative salience. It remembers the negative experiences, but forgets the positive ones. And so therefore, by remembering the negative stuff, your whole worldview, and therefore your decision making processes, are based upon the negative experiences that dominate over positive ones.

How much sleep is enough?

Sleep is genuinely like shoe size, one size does not fit all. And so in the healthy population, the sleep range can go from six hours to nine or 10 hours - outside that there are there are likely to be problems but that is the range.

it's not rocket science. I mean, how do you know if you're getting enough sleep? Well, are you able to perform at the level you want to perform during the day? Are you able to work at the level that you feel is optimal?

There are other guidelines. Do you need an alarm clock to wake you? Are you irritable? Do you feel fatigued? Do you crave a nap during the day? Do you find yourself doing unreflective impulsive behaviours? Do you crave caffeine and sugar rich drinks, and do your friends, family and colleagues talk about increased irritability, loss of empathy, or you being more disinhibited? Now, if it's yes to those then okay, well I'm not getting the sleep I need. 

You do some mythbusting in the book. There’s been a lot of talk about blue light from the screens of smartphones and other devices stopping people getting a good night’s sleep - but you say the light isn’t the real problem?

These devices allow you to constantly switch between catch up radio, between news events, between Twitter, between emails, and they are very, very alerting. And so I would not advise using these devices 30 minutes before trying to get to sleep because of the brain alerting effects, rather than the light effects. 

But for some people, a Kindle could be a very relaxing way of getting off to sleep.

You feel so strongly about sleep, you seem to be convinced that we almost need to put it on the national curriculum - it's that important?

It's 30% of our biology, you know, and we don't arm either our young people, our workforce, frontline staff, even our medical students with the importance of this biology. It is, I think, breathtaking. I think the low hanging fruit would be to introduce basic sleep education into the schools as part of the national curriculum to arm the kids not only for now - and the data are very clear in terms of improved grades, reduced self-harm, reduced truantism, reduced depression - but it also arms them with this information as they age as well

There's no education for nightshift workers generally explaining how this will affect their health, not only them but also their partners. The divorce rate is sometimes six times higher in some groups during the night shift versus the day shift. And the partners need to know that it's not that the wonderful person that they married earlier in their life has turned into a monster. These are the consequences of driving our biology outside of its normal physiological range.

I will make available a video of the full conversation with Professor Foster, at first just for paying subscribers.

Life Time, The New Science of the Body Clock, and How It Can Revolutionize Your Sleep and Health by Russell Foster (Penguin Life) is out now, RRP £16.99