Sleep - our new obsession
The new Western obsession is sleep - or a lack of it. Jo Revill, health editor, reveals new research that lifts the lid on how much we really need.
Sunday April 9, 2006
The Observer
London, UK
Sleep, or rather our frustration at not having enough of it, is the new health obsession. Worries about diet, pollution and exercise have given way to new anxieties about insomnia. We are told that the nation is building up a 'chronic sleep debt' because our modern lifestyles don't allow us to spend enough time in bed after a long day.
It is a new sort of epidemic, with millions being spent on sleeping pills to 'cure' those who can't drop off at night. Interrupted sleep is now one of the most common complaints aired in the GP's surgery. Everything from parenting problems to diabetes and career setbacks are blamed on a 'sleep disorder pattern' which is fuelling an industry of therapists, drugs and devices.
Now a new book by Britain's leading expert on the subject sets out our real relationship with sleep. It argues that most of us get quite enough, and that the present generation enjoys a better-quality night-time than our ancestors ever had. Instead of obsessing about sleep debt, we should realise that the key to feeling energetic and focused in the morning is what we do in the waking hours, not whether we are getting enough time with our heads on a pillow. Even those who wake up frequently at night are probably getting sufficient sleep.
Professor Jim Horne is the experts' expert when it comes to sleep research in Britain, and his views will annoy some people because he does not pander to the idea that we are all chronically deprived of sleep. But he celebrates the fact that we know so much more now about 'Nature's soft nurse' than in the past, and that it's there to enjoy: we should stop being so hung up on it. Sleep is now something, finally, we can understand. As mornings become lighter and Easter approaches, many of us find ourselves waking early. Long before the alarm clock goes off, you're opening your eyes, reacting to the combination of early sunlight and the April dawn chorus. But how is the body able to fine-tune itself so exactly to the seasons when we live in such a hectic, technology-driven world?
The last 10 days would suggest that we are hopelessly out of synch, given the plethora of stories warning of the dangers of sleeplessness. The New York Times said that insomnia was pushing thousands more people into taking prescribed drugs for the condition amid concern that younger people are finding it particularly hard to doze off. The British Association of Counselling is reported as saying that 12 million people have at least three bad nights of sleep a week. Then the RAC warned that sleepy drivers were responsible for 20,000 crashes last year.
Horne wants to change the tone of the debate, arguing that the human body adjusts to different sleep patterns with great agility. This is because our lives are governed by a body clock which affects not only the timing of sleep but also the different levels of alertness or lethargy. These 'circadian rhythms', which govern our moods and energy levels, are set by the body clock, which in turn is synchronised by sunset and sunrise, and also by more modern cues such as artificial light, the alarm clock, even the daily addiction to a particular TV soap.
But this timepiece, which in prehistoric times would allow us to rise early to have the best chances of survival and hunting, can be shifted by our own irregular lifestyles. For example, a very bad night's sleep will affect your level of alertness so that by 10am, when you would normally be awake and highly receptive to people around you, you will still be in a sleepy phase. Afternoon sleepiness is an entirely natural phase of the body clock, and is the human way of getting through the day. 'Some people think that because they feel tired in the afternoon something is wrong with them, but that is not at all the case,' said Horne. 'It's a natural dip in the day.'
The afternoon siesta is still common in hotter countries but is something that might benefit people in cold climes too. Winston Churchill was a proponent of the afternoon kip, and stuck to this routine during the Second World War. Later he wrote: 'You must sleep some time between lunch and dinner, and no half-way measures. Take off your clothes and get into bed. That's what I always do. Don't think you will be doing less work because you sleep during the day. That's a foolish notion held by people who have no imagination. When the war started, I had to sleep during the day because that was the only way I could cope with my responsibilities.'
Throughout the ages, humans have regulated their sleep according to their working lives. Five centuries ago Britons enjoyed something known as 'fyrste slepe', an early evening nap. Supper usually followed, then a period of prayer or talking. People would then stay awake until the early hours of the morning, then had a five to six-hour sleep.
'It seems to me that a night of between seven and eight hours' sleep is a fairly modern western development, which is clearly linked to industrialisation,' said Horne. 'Human beings are very adaptable, and we should keep that in mind because we tend to think of these hours as sacrosanct, when in fact we are far more flexible than we like to think.'
The reality is that we probably sleep more now than our ancestors did 100 years ago. 'Increasingly you hear people talking about us all having a chronic sleep debt, and that you have to catch up with it, but I'm not sure that is true,' said Horne.
'Think back to what life was like in Dickensian times. People were working 14-hour days, six days a week, and there was no lie-in on a Sunday as you were up for church. At night they would return to bedrooms they would share with children, to beds infested with bugs, in a noisy environment. The great majority of people were not getting eight hours of uninterrupted rest. But they didn't think about it in that way, or if they did feel tired they kept quiet.'
What exactly is sleep? The myths and beliefs that have surrounded the time we spend dead to the rest of the world have always mattered to successive civilisations. Aristotle thought it resulted from the warm vapours rising from the stomach after a good meal. But that was 2000 years ago, before we had EEGs (electroencephalograms) to measure the brainwaves we emit in sleeping hours.
Sleep is far more than an absence of body movement or a closing of the eyes: it is to do with the profound changes that take place in the cortex, the part of the brain that controls all the higher functions - the intellect, the imagination, social responsibility and love. By looking at the brainwaves that emerge from this region using an EEG, scientists can study the different stages of sleep. The process may seem continuous but is actually broken up into 90-minute spells. What tends to happen is that, soon after you nod off, you will go into a deep sleep. The brainwaves alter in their height and number, and move from becoming 'small ripples to large rollers', as Horne puts it. 'These deep waves, affecting your levels of consciousness, enable the body to block out external noises and movement and to maintain sleep, and will make up between 10 and 20 per cent of a night's sleep for a typical adult. It usually happens in the first half of the night.'
Much research has gone into the stage of sleep known as REM (rapid eye movement) first identified in 1955. The name is rather a misnomer, because during this time the eyes are mostly not moving at all. The rapid jerky movements under the eyelid first described by Professor GT Ladd in 1892 were associated with dreaming. In fact, the most vivid and intense dreams do occur during the REM period, but in the rest of sleep you also dream, although the images tend to be milder and more reflective.
Dreams are created in the cortex, but REM derives from a much deeper part of the brain which seems less connected with thought processing and more to do with memory storage and wakefulness. 'Some have compared this stage to a screen-saver on a computer - it's the mode into which the brain can retreat when it is in a state of non-wakefulness,' said Horne.
'We know that sleep looks after many, many processes which affect your personality, your memory, your thoughts, your feelings - really everything that makes you human and able to function. The many studies on sleep deprivation show us that these fragments of who you are start to break down once you take away essential rest.'
What is exciting new interest - and what few of us realise - is that the amount of deep, beneficial sleep you get really depends on the amount of time you have previously spent awake. It seems the deep waves are crucial for enabling the cortex to recover its powers, or 'recharge' before it can cope with the next day. A fairly new discovery is that there are very slow waves within this deep sleep that appear to be particularly important for the brain and affect the workload that the cortex can deal with during waking hours. But someone who regularly sleeps for just five hours can enjoy the same amount of deep sleep as the person who has nine hours a night - and there is no research to suggest that one is less alert or energetic than the other.
We think of insomnia as a modern condition, as a state created by the internet and constant news coverage and 24-hour cafes. The film Lost In Translation, starring Bill Murray as an exhausted actor unable to sleep in his Tokyo hotel, conveys the sense of weariness with modern pressures. His exhaustion is expressed by the boredom and frustration of his situation, and a desire to escape.
But is it really anything new? 'The hurry and excitement of modern life is held to be responsible for much of the insomnia of which we hear; and most of the articles and letters are full of good advice to live more quietly and of platitudes concerning the harmfulness of rush and worry. The pity of it is that so many people are obliged to lead a life of anxiety and high tension.' This statement comes from the British Medical Journal but was written in September 1894. It entirely conveys what most people feel is the truth now about life in Britain.
Everyone has had the experience of trying to go off to sleep, only to find that their mind is still buzzing and that the more they try, the harder it is to find rest. But Horne's research in Loughborough has shown that most people don't take that long to doze off. The period of time measured from the 'lights out' moment to nodding off is around 10 to 30 minutes, although in 25 per cent of cases it can take longer than that. There is an interesting difference between the sexes. After the age of 50, men report falling asleep much faster - averaging about 13 minutes compared with 22 for women. It appears to be older women who have most problems in getting off to sleep.
Most of us go to bed between 11pm and midnight, although women tend to go somewhat earlier than men. There are, however, people who survive well on five hours' sleep and also those who need nine hours. The average daily sleep over the past 40 years turns out to be between seven and seven and a half hours, across the West. What is more, the human being's ability to sleep in virtually any circumstances is well documented in history. The phrase 'hangover' does not come from some alcohol-related source but from the bedtime tradition in Victorian workhouses. Workers lined up along a bench and a rope was tied from one end to the other, allowing them to sleep by draping their arms over the rope which they 'hung over' as it supported them.
Horne, who has carried out research on thousands of volunteers at his sleep laboratory, believes that, although around one-quarter of the population may feel they get insufficient sleep, there is very little firm evidence to support this. Tests measuring cognitive performance show that when people have lost two hours a night, it does not affect ability to perform tasks. 'Much of the insomnia is self-diagnosed, and it's easier to take a patient's word for it and prescribe tablets than to sort out whether they are really sleep-deprived,' he said. 'When a whole society starts to think it has a chronic sleep debt, then you are going to increase the problems. A lot of sleepiness is more imagined than real.'
But there are many who argue against Horne when he questions the whole idea of a sleep debt. Professor Russell Foster, an expert in circadian rhythms at Imperial College London, said: 'A few days of not getting enough sleep won't harm you, but there is a cumulative effect that you see, and there is evidence that it can affect your cognitive performance. I think western societies are increasingly 24/7, increasingly sleep-deprived and increasingly reliant on stimulants. Why is it that the second most traded commodity after oil is coffee beans? Because we can keep ourselves awake for longer. The problem comes at weekends when we then want to relax but find it hard, so we use alcohol and sedatives to do so. Yet sleep is more important than ever to us, because in Britain we don't have a manufacturing base any more, we are reliant on our creative processes, and for individuals to come up with really novel ideas and decisions, they need to enjoy regular, good-quality sleep. There's no getting away from it.'
The struggle to get enough sleep is one of the most common complaints of modern life, and like everything else it therefore demands 'a quick fix'. More than £20m a year is spent in Britain on sleeping pills, but these are short-term therapies which usually stop working after four weeks and can be difficult to withdraw from. The older benzodiazepine drugs have left thousands of people dependent on them, although they carry side effects and do nothing to sort out the problems of insomnia.
Back in the Eighties, when doctors worked gruelling 90-hour weeks, there were many accounts of accidents and errors made by clinicians who were too tired to think properly. The results of such long hours without rest led to a big change in working patterns, and finally to the European Working Time Directive, which now means that no one must work more than a week without a break.
One doctor who remembers what it felt like to be so tired is Sarah Marwick, who now works as a GP in Birmingham. 'Like all junior [doctors], I had to work shifts in Accident and Emergency for six months, and I felt constantly drained, and a feeling of jet lag the whole time. I felt under par continuously, which made me very stressed and irritable. At the end of a 36-hour shift I felt I was drunk. I couldn't concentrate, felt like I had to work hard and really think to get words out.'
Marwick, who shared her experiences with other doctors on the online forum Doctorsnet.org.uk, found that on a number of occasions she would be asked the next morning about something she had done the previous night at the end of a long period on call, and she would have no recollection of it, or even having been to the ward, or giving intravenous drugs.
'But the scariest time was when I fell asleep while driving home after a weekend on call. I was sitting at a traffic light in the city centre and I must have dozed off. A man had to come and knock on the car window and wake me up, and he said he had been beeping his horn and I had not moved for a good three minutes. It could have been fatal.'
For doctors at least, those long working hours have been reduced, as they have in other professions with new European rules. The irony is that, as our working hours lessen, we feel more tired than ever, perhaps because of all the other tasks that we impose on ourselves in our spare time. In the desperate desire for more sleep, an entire industry has grown up around the problem - university departments, journals, academics and clinics as well as a 'National Sleep Awareness Week' are there to make us aware of the problem. And so are the breathing masks, the nose pillows, the aromatherapy solutions and sleep clinics.
Even the people who started the research in laboratories, such as Jim Horne, are aware of the dilemma. One of them is Dr William Dement, who runs the Sleep Disorders Clinic at Stanford University in California and founded the concept of sleep medicine decades ago in the US. 'Nutrition, fitness and now sleep,' he told the New York Times recently. 'Twenty-five years ago, everyone started jogging and worried about their fitness. Now sleep is having its moment.'
Perchance to dream
Sleep is an altered state of consciousness, as opposed to an unconscious state. It allows the brain to undergo a complex recovery process, and as the brain 'winds down' into sleep mode, you physically become less aware of the surroundings.
Sleep is the regular state of natural rest observed in all mammals, birds and fish, and is characterised by a reduction in voluntary body movement.
The circadian rhythms which govern the body clock, and hormonal and environmental factors all affect your ability to sleep.
Sleep appears to perform a restorative function for the brain and body, and we know this because of the many symptoms of personality and behaviour change which are seen when humans and other animals are deprived of it.
Sleep is also a time for healing and growth. When you go into deep, or slow-wave sleep, growth hormone levels increase, and changes in immune function occur. In babies, sleep is essential for processing new information about the environment.
One process known to be highly dependent on sleep is memory. REM (rapid eye movement) sleep appears to help with the consolidation of spatial and procedural memory, which is the long-term memory of acquired skills essential for surviving in the modern world.
But another view is that sleep serves an evolutionary function in simply protecting people during the hours of night, at a time when roaming around would place the individual at greatest risk, according to some experts. Organisms don't require 24 hours to feed themselves and meet all other necessities, so they are safer asleep and out of harm's way.
They sleep, therefore, at times that maximise their safety, given their differing physical capacities and their various habitats.
http://observer.guardian.co.uk/focu...1750064,00.html
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