Lack of deep sleep in old age can trigger memory loss: study

Scientists found people in their 70s performed 55 per cent worse in a simple memory test than individuals in their 20s, even though they had the same hours of rest.

Brain monitoring showed the quality of deep slumber, known as slow wave sleep, enjoyed by older participants was up to 75 per cent worse - with those getting the least deep sleep found to have the poorest recall, the 'Daily Mail' reported.

The study found why older people's memories do not benefit as much from sleep as younger individuals.

Researchers suggested that by stimulating deeper sleep, it may be possible to boost memory maintenance in the elderly. They hope this could one day offer new treatments to help limit the effects of dementia.

 

"How bad the quality of deep sleep the participants enjoyed the night before was directly predictive of how poor their memory would be the next day," Professor Matthew Walker, principal investigator at the University of California's Sleep and Neuroimaging Laboratory, said.

"The older participants, who had much poorer quality deep sleep the younger individuals performed on average 55 per worse on memory tests," he said.

The scientists hope that if they can find a similar relationship in people with Alzheimer's, it could open up new avenues of targeted treatment to help improve memory.

In the study, 36 healthy young and older adults were asked to learn a set of words.

The researchers then tested subjects' memory either immediately after learning the list or after a night of sleep. Their brain function was also monitored when they slept.

The study found that a particular part of the brain shows the greatest degree of deterioration as we age, and it is directly linked to our quality of sleep. Those who had the most deterioration also suffered the worst quality of sleep, and additionally had the poorest recall the following day.

"We established a relationship between brain deterioration in older people and the decline in the quality of deep sleep. And the second finding is that lack of this deep sleep was directly linked to memory loss," Walker said.

The study was published in the journal Nature Neuroscience.