For 264 hours, Randy Gardner did not go to sleep. He felt tired, but each time
the urge to rest his head on a pillow came upon him, he played basketball
and, after 11 days and nights in January 1964, he broke the world record for
sleeplessness. He thanked his supporters, held a press conference and
promptly passed out.
This achievement is being celebrated 43 years later (along with other
sleep-related research) at an exhibition starting next week in North London.
Scientists don’t really know exactly why we sleep, but the Sleeping
and Dreaming exhibition at the Wellcome Collection will raise questions
about whether we need to sleep at all. As science gallops ahead, would it be
possible, one day, to take a pill and banish sleep for ever?
There are conflicting theories about the purpose of sleep. But the fact that
we spend about eight out of every 24 hours asleep suggests that there are
powerful evolutionary reasons for its continuing existence. Most theories
centre on the beneficial effects that sleep has on the brain; this is
because there is little evidence of any direct physiological effects on the
body. Tissue seems to repair, regenerate and grow normally during times of
sleep deprivation. Some scientists believe that sleep is a time for the
immune system to regenerate, while one theory suggests that sleep evolved as
a way of coping with limited supplies of food.
The dominant theory is that sleep is a time for the brain to store memory. The
idea is that during sleep the brain, in effect, goes offline to file the
events of the day. Another theory is that the brain is a complex organ that
needs the downtime provided by sleep to recover from the stresses of waking
hours. “While we are awake, the higher centres of the brain are working flat
out,” says Professor Jim Horne, who runs the sleep laboratory at
Loughborough University. “Even when you are lying down, the brain is in a
state of quiet readiness, ready to respond. The only time it can rest is
during sleep.”
He adds: “Sleep is important because we know that, even when people know they
will die if they go to sleep, like shipwrecked sailors or overtired pilots,
they still do so. Nature has provided nothing that overrides this.’’
Under five hours sleep is unhealthy
Researchers who champion these brain theories point to the fact that behaviour
changes significantly with sleeplessness. A person who is lacking sleep
takes more risks, has slower mental processes and reacts to events with more
emotion and less logic. One theory is that brain circuitry needs to be
repaired and maintained regularly and that when this maintenance work is not
carried out during sleep, the workings go awry, with communications slowing
down or being wrongly routed if you don’t get enough sleep. So how much
sleep do you need?
Some research suggests that while seven to eight hours a night is healthy,
under five hours or more than eight is unhealthy, and linked to disorders
such as heart disease, depression, diabetes and high blood pressure.
However, there are reports of people surviving on less than five hours.
Margaret Thatcher is reported to have run the country on four hours a night.
“Some people claim that they can survive on very little sleep,” says
Professor Horne. “But when we look into it, we find that Churchill and
Thatcher took naps. Churchill had four hours a night and a two-hour siesta
in the afternoon with his pyjamas on.”
Could a pill banish sleep for ever?
In our busy modern lives, however, sleep can sometimes be seen as
nonproductive time, and many people would love to have an extra eight hours
in their day. As a result, various research projects have been looking at
how sleep needs can be reduced. Many chemical compounds that keep you awake
– such as amphetamines and caffeine – have been examined but, so far, there
has been no discovery of a drug that can safely replace sleep.
The US military has been funding research into genes. Keen to have soldiers
alert for up to 72 hours a time, army scientists have homed in on a genetic
mutation that has a powerful effect on the amount of time fruit flies sleep.
In a four-year study, researchers at Wisconsin University screened 9,000
mutated fruit flies and found that one group slept a third the amount of
normal flies. The gene involved is called Shaker and it is concerned with
the flow of potassium into cells, a process that critically affects, among
other things, electrical activity in nerve cells in the brain. Potassium
also seems to be involved in the generation of sleep in human beings. The
discovery could, the researchers say, lead to new ways of prolonging
wakefulness.
Professor Horne, who is the author of Sleep-faring: A Journey Through the
Science of Sleep, is sceptical: “Some people do suggest that we could
have some sort of sleep pill that we can pop into the mouth and say goodbye
to sleep, but I think it is largely nonsense. There must be 100 mechanisms
in the brain that integrate sleep, and the idea that such a complex process
could be changed by one pill seems nonsense.’’ He points out that no one
knows the long-term effects of sleep deprivation. Eleven days is the most
that anyone has gone without sleep, and Randy Gardner’s doctor described him
at the end as being cognitively dysfunctional. It is also known that rats
die after several days of sleep deprivation. And the Wisconsin research
suggests that while the fruit flies needed much less sleep, they also died
at an earlier age.
Would any of us, even the most time-pressed, really swap a long life with
plenty of duvet-hugging for a short, sleepless one?
The Sleeping and Dreaming exhibition, the Wellcome Collection, 183
Euston Road, London NW1, until March 10. For more information, www.wellcomecollection.org
IF YOU SLEEP FOR LESS THAN:
4 HOURS Your immune system becomes compromised. When researchers at the
University of Chicago exposed sleep-deprived students – four hours a night
for six nights – to flu vaccine, their immune systems produced
only half the normal number of antibodies. Stress levels rose, raising heart
rates and blood pressure.
5 HOURS Your risk of diabetes increases. Research at Boston University
School of Medicine suggests that those who have less than five hours a night
were 2.5 times more likely to develop diabetes compared with those
having seven to eight. You also increase the risk of being overweight.
According to research at Bristol University, the rise in obesity may
be partly because of the reduced amount of time we spend asleep. People who
sleep for five hours were found to have 15 per cent more ghrelin, a hormone
that increases feelings of hunger, than those who slept for eight
hours. They were also found to have 15 per cent less leptin, a hormone that
suppresses appetite.
6 HOURS Watch out for high blood pressure. A study reported in Hypertension
suggests that those who sleep less than six hours a night had more than
double the risk of high blood pressure.
IF YOU’VE BEEN AWAKE FOR:
10 HOURS Levels of the stress hormone cortisol begin to rise. There may
also be changes in blood pressure.
12 HOURS The likelihood of having a car accident more than doubles.
Heart rate begins to slow.
17-28 HOURS Speed in mental tasks slows to the equivalent of someone
who has drunk the drink-drive legal limit of alcohol.
24 HOURS Risk-taking behaviour increases. Verbal fluency declines.
48 HOURS Effectiveness of immune system declines.
53 HOURS Ability to make moral judgments declines.
72 HOURS Speed and accuracy in computer tests drop to 30 per cent of
normal.
85 HOURS Brain activity declines significantly.
11 DAYS Longest documented period of voluntary sleeplessness is 264
hours. No long-term harmful effects found.
Sources: US Federal Highways Commission; University of New South Wales;
University of California, San Diego; North Carolina University; Walter Reed
Army Institute of Research; Johns Hopkins University
