Sleep deprivation 'may lead to illness'

Feb 5 2009 The Journal

WHY we spend around a third of our lives asleep has long puzzled scientists.

Now a study involving Durham University anthropologist Professor Robert Barton has found evidence that a good night’s sleep helps health by fuelling the immune system.

The research explored sleep in mammals but could have implications for human health and help to better understand the role of sleep in keeping illnesses at bay.

The findings show that animal species that sleep for longer do not suffer as much from parasite infestation and have a greater concentration of immune cells in their blood.

"We assume there must be important benefits from sleep since animals, including humans, spend so much time doing it," said Prof Barton.

Evidence indicates that sleep deprivation leads to greater vulnerability to infections and also affects memory. Across a wide range of mammals, sleep seems to be a crucial factor in avoiding disease.

"It is the first time that a strong relationship has been found between sleep and anything else across species," said Prof Barton. "A lot of energy is needed to run the immune system – it is very expensive body-wise. When you are awake, energy is being diverted elsewhere so we think that when you are asleep extra energy is diverted to support the immune system."

Prof Barton said there seemed to be some truth in the belief that some people were owls and others larks – and suggested men were more likely to be owls and women larks. This could be because there were evolutionary benefits in men staying awake longer to ensure their female mates were not appropriated by rivals.

"Maybe some people are genetically more capable of sleeping less without exposing themselves to greater risk of disease," he said.