Study reveals just one sleepless night could spark Alzheimer's

Just one sleepless night has been found to cause the build-up of a protein linked to the devastating condition. Photo / 123RF

Sleep deprivation may raise the risk of getting Alzheimer's disease.

Just one sleepless night has been found to cause the build-up of a protein linked to the devastating condition.

A study of 20 people found a night without sleep increased the beta-amyloid protein in part of the brain by five per cent, the Daily Mail reports.

People with mild memory loss have 21 per cent more beta-amyloid in their brains than healthy elderly people, while those with Alzheimer's disease have 43 per cent more beta-amyloid.

While previous studies have shown similar brain changes in mice, this is the first to show brain changes linked to Alzheimer's after a sleepless night in the human brain.

Sleep is vital in clearing away beta-amyloid, which can form clumps in the brain to block important pathways for memory.

However, it is not clear if the effects of a sleepless night are long-lasting or are seen only the day afterwards.

The study's lead author, Dr Ehsan Shokri-Kojori, from the National Institutes of Health in Maryland, said: 'Often brain changes seen in animals are not replicated in humans, so this is interesting.

"The increase in beta-amyloid we saw in the brains of people who were sleep-deprived is likely to be a harmful process.

"A reasonable prediction based on these results would be that poorer sleep habits create a risk for Alzheimer's disease."

Researchers examined the effects of sleep deprivation on 20 healthy people aged 22 to 72 over the course of two nights.

For one of those nights the group were allowed to sleep from 10pm to 7am, while on the second they were kept up all night long.

Their brains were scanned afterwards to show a 'significant increase' in amyloid-beta in two regions of the brain vulnerable to damage in Alzheimer's patients.

The hippocampus plays a key role in memory while the thalamus acts as a relay centre for motor and sensory nerve signals.

After a sleepless night, the group had five per cent more beta-amyloid than if they had got a full night of rest, according to the study published in the journal Proceedings of the National Academy of Sciences.

Sleep may play an important role in a natural 'waste disposal' system that clears potentially harmful material including amyloid-beta out of the brain, scientists believe.

Dr David Reynolds, chief scientific officer at the charity at Alzheimer's Research UK, said: "There is growing evidence of a link between disrupted sleep and Alzheimer's disease, but it is difficult to tease apart cause and effect to determine whether sleep problems might cause Alzheimer's brain changes or vice-versa.

"This very small study suggests that one night of sleep deprivation can raise levels of the hallmark Alzheimer's protein amyloid, strengthening suggestions that sleep is important for limiting the build-up of this protein in the brain."