How lack of sleep affects the brain

by PAUL KENDALL, Daily Mail

As every parent of young children knows only too well, failing to get a good night's sleep tends to leave you feeling tired and irritable.

But the effects can be far more serious than that, researchers claim.

They have found that disturbed sleep patterns can impair memory, shrink the brain and raise stress levels.

Anyone whose body clock is regularly disrupted, such as nursing mothers and shift workers, is vulnerable.

Scientists from the University of Bristol studied the effect of jet lag on airline cabin crews.

All the volunteers were female and had been air stewardesses for five years, but half had intervals of less than five days between long-haul flights, while the other half had longer intervals of more than 14 days.

Research leader Dr Kwangwook Cho used scanning technology to measure the size of the temporal lobe region of the volunteers' brains.

He found this region - which is critical to memory - had shrunk among those crew with the shortest intervals between flights. The group with longer intervals did not suffer in the same way.

Further tests showed that those whose brains had shrunk had worse memories and higher levels of the stress hormone cortisol.

Past research has shown that chronic high cortisol levels due to severe depression and post-traumatic stress is associated with temporal lobe shrinkage.

In the journal Nature Neuro-science, the scientists said: 'Cortisol levels in cabin crew after repeated exposure to jet lag were significantly higher than after short flights.'

They said that prolonged increases in cortisol levels shrank the temporal lobe and affected learning and memory.

Around 3.8 million Britons now work night shifts.

A third of the population suffer from sleep- related problems and studies have shown that we are all getting far less sleep than we used to.

The average person now sleeps for seven hours a night - compared with nearly nine a few decades ago.

Many scientists believe that irregular sleeping patterns lead to illnesses, ranging from aches and pains to heart disease.

Sufferers can go on to develop chronic fatigue syndrome, which causes overwhelming tiredness, poor concentration, irritability and depression - similar to permanent jet lag.

Less than eight hours' sleep a night can lower IQ the next day, while working night shifts increases the risk of diabetes, ulcers and divorce.

And researchers at the University of Surrey have found that upsetting the body clock can keep levels of glucose and fat in the blood dangerously high after a meal.

Many people - most famously Lady Thatcher when she was Prime Minister - claim they can survive on less than six hours a night.

As well as the effect on health, marriages in which one partner works nights are up to six times more likely to end in divorce, a recent study showed.

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