London -Experts say skipping just an hour or two of sleep a night can harm health. But this doesn’t bother dentist Dr Uchenna Okoye. She wakes every morning at around 4.30am - out of choice.
“For me, a lie-in is getting up at 6am,” she says.
Usually asleep by around 11pm, Dr Okoye even rises early following nights when she has gone to sleep much later.
“Last night, I had a work do to attend and accounts to get through after that, so I didn’t go to bed until 3am,” she says. “But I automatically opened my eyes at 6am, without setting the alarm.
“It’s very rare for me to feel sleepy during the day, and I know as a doctor this is the measure of whether you sleep enough.”
Both her parents were early risers and Dr Okoye believes she has inherited this.
“My father used to tell us that sleep was practising death and as kids we had to be at the breakfast table at 6am every day, no matter what happened the day before.”
Dr Okoye’s husband Chidi Ngwaba, a doctor, used to find her early rising hard to cope with.
“He is the opposite to me - he loves staying up late and sleeping in. To keep the peace, when we go on holidays we always book a suite so I can quietly get up and work in the other room and he can sleep.”
The number of Britons who, like Dr Okoye, get just five to six hours sleep a night has risen dramatically in the past three years.
A report from the Sleep Council last year suggested that 33 percent of us get by on five to six hours’ a night, compared with 27 percent in 2010. The average Briton today gets around six hours and 35 minutes’ sleep.
Only around five percent of us function well on little sleep, so this drop in an average night’s resting hours might be deeply worrying. It might also help explain the significant rise in prescriptions for drugs to treat insomnia, including zopiclone and temazepam.
According to the Health and Social Care Information Centre, fewer than ten million prescriptions were written in 2002, rising to more than 15 million in 2012; one in three people now complains of suffering from bouts of insomnia.
However, experts such as Derk-Jan Dijk, professor of sleep and physiology at the Surrey Sleep Research Centre, now emphasise that it’s the quality of sleep, rather than the quantity, that is important.
“Sleep need is individual and can vary from five to nine hours,” says Professor Dijk. “A quality night’s sleep isn’t necessarily going to be eight hours for everyone.”
Sleep with interruptions can reduce its restorative effects, so “quality sleep” is often defined as being uninterrupted, allowing the body to go through the different sleep stages that restore emotional and physical well-being, he explains.
To measure sleep quality, scientists rely on people’s daytime sleepiness. “If you feel sleepy and doze off during meetings, take longer than normal to complete tasks or at weekends sleep much longer, then the sleep you are getting may not be of good quality,” says Professor Dijk.
Ironically, worrying about getting a full eight hours could be one of things stopping us getting a quality night’s continuous slumber. At night, hormones such as melatonin - produced when the body is exposed to darkness - and serotonin - a calming brain chemical - should kick in to make us sleepy.
However, when we start to worry about something, the effects of these can be outweighed by stress hormones such as adrenaline and cortisol.
For those of us blighted by erratic sleep patterns, doctors now believe Dr Okoye’s blase attitude towards slumber could be the key to getting better sleep.
“The paradox is that being less fixated on sleep is the key to getting a better night’s sleep,” says Colin Espie, professor of clinical psychology and director of the Sleep Research Laboratory at the University of Glasgow.
“There are things our bodies and brains are designed to do automatically. Sleep is one, and it’s determined by biology and genes.”
This means some people naturally need more or less sleep than others, and this can vary widely. The amount you need is wired into your biology like your fingerprint, says Professor Espie.
But such natural functions get impaired by our anxiety to perform them well.
“People with insomnia will often wake in the middle of the night and think: ‘Oh my God! I can’t sleep.’ And that starts their alarm bells.
“They lie there worrying about not sleeping, thinking: ‘I am awake again, I am going to perform badly at work tomorrow, I am going to feel awful, I need to get to sleep.’?”
That puts the brain into threat mode, in which the body responds physiologically as though it is being attacked, releasing stress hormones such as adrenaline and cortisol to help it deal with a perceived danger, explains Professor Espie.
“This is the exact opposite to the relaxed state the body needs to be in to fall asleep.”
For Dr Okoye, 44, sleeping less has corresponded with getting older. In her 20s and early 30s, she would sleep for seven hours; now it’s for about five.
This need for less sleep as we get older is not uncommon.
“Many older people still expect to get the eight hours of sleep they got when they were younger and lie in bed worrying about getting less now,” says Professor Dijk. ‘This is not necessarily conducive to getting a quality night’s sleep.
“People often think there is something wrong, when in reality - if their sleep is of good quality - it’s just normal,” he says.
In fact, research shows older people who have fewer than the traditional eight hours are less sleepy during the day.
In one of Professor Dijk’s studies conducted at Harvard Medical School, people over 60 and people in their 20s were asked to spend 16 hours in bed.
The older people managed to sleep for only seven-and-a-half hours of that, while the younger ones slept just under nine.
Professor Dijk’s team recorded their brainwaves and found older people who slept fewer hours were less sleepy during the day than the younger ones.
“Research indicates that older people get less sleep and probably need less sleep, and shouldn’t be worried about that,” he explains.
‘Sleep is related to plasticity of the brain, it has to do with learning new skills and memory. Young people’s brains are always learning and thus need more sleep.’
“They should be worried if they feel sleepy during the day because that indicates they either don’t get enough quality sleep or there’s some underlying sleep problem.”
Of course, there are real forms of insomnia as distinct from that caused by worrying about not getting enough sleep. Typically, these are caused by stress or underlying medical conditions such as diabetes, heart disease or osteoporosis, or medications including painkillers or antidepressants.
Recent research from Harvard Medical School found that increased smartphone and tablet use at bedtime suppressed the sleep-inducing hormone melatonin.
But if it’s quality of sleep, not quantity, that matters, does this mean we can ignore the regular dire warnings about the health effects of lack of sleep?
Just last week, a study from Uppsala University, in Sweden, found that being sleep-deprived caused a similar change in the brain to that seen after a head injury. Other conditions that have been linked to chronic lack of sleep include multiple sclerosis, and a greater risk of heart attacks, strokes and angina - possibly because sleep deprivation raises blood pressure, which increases the risk of artery damage.
Professor Dijk says there is no good evidence that not getting enough sleep raises the risk of MS. However he explains: “For some other conditions, such as cardiovascular disease, obesity and diabetes, epidemiological evidence suggests that abnormal sleep patterns - defined in most studies as less than six hours a night - are a contributing factor.”
So how does the new emphasis on quality, rather than quantity, of sleep square with links to such health problems? “We don’t know the answer to that because most studies have only looked at self-reported sleep duration without measuring sleep quality,” he says. “Risk increases when you consistently sleep less than your body needs.”
Meanwhile, one of the most effective treatments for insomnia caused by sleep anxiety involves asking patients to essentially give up on sleep. Called paradoxical intention therapy (PIT), patients instead try to stay awake.
PIT is recognised by the American Academy of Sleep Medicine as one of the few evidence-based psychological therapies for sleep, and - although not available on the NHS for sleep problems - is an acknowledged therapy practised by UK psychologists.
“Patients realise that when they try to remain awake, they feel sleepier. People who sleep well don’t try to sleep,” says Professor Espie, who has pioneered the study and use of PIT.
“Reading is a classic example, especially if it’s an engrossing book, as it’s often trying to stay awake and read more that makes people fall asleep naturally,” he explains.
And, finally, here’s something that might relax those with sleep anxiety - they may be getting more than they think.
“Often we will ask someone who reports having insomnia: ‘How long did you sleep?’ and they say: ‘Two hours,’?” says Professor Dijk. “Then we measure their sleep by recording brainwaves and other signals and find they actually slept six-and-a-half or seven hours.” - Daily Mail