Lack of deep sleep in old age 'can contribute significantly to memory loss'People in their 70s did worse in a memory test than those in their 20s, even though they had same hours of restMonitoring showed quality of sleep enjoyed by older people up to 75 per cent worseResearchers suggest by stimulating deeper sleep, it may be possible to boost memory maintenance in the elderly
20:44 GMT, 27 January 2013
20:44 GMT, 27 January 2013
A lack of deep restorative sleep in older people significantly contributes to memory loss, a new study has found.
Getting a good night's sleep has been linked to how well adults remember events the following day. But 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.
A lack of deep restorative sleep in older people contributes to memory loss, a new study has found
The study explains why older people's memories do not benefit as much from sleep as younger individuals.
Researchers suggest 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, which affects more than 800,000 people in Britain.
Professor Matthew Walker, principal investigator at the University of California's Sleep and Neuroimaging Laboratory, said: '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.
'The older participants, who had much poorer quality deep sleep the younger individuals performed on average 55 per worse on memory tests.' 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.
Sleep well: A good night's sleep has been linked to how well adults remember events the next day
'The older you get, the worse the quality of the deep sleep you enjoy gets. We cannot change that.
'This sleep is needed for the brain to press the record button and help store your memories. The silver lining is that we can stimulate the brain so people can enjoy more of this deep restorative sleep.
'If sleep is a piece of the puzzle in Alzheimer's, then if we can improve the quality of their sleep, we would also hope to improve their memory as well.' In the study, published in the journal Nature Neuroscience, 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 older you get, the worse the quality of the deep sleep you enjoy gets'
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.
'There are three factors that are already well known, as you get older you lose memory, have increasingly bad sleep and suffer brain deterioration. We wanted to find out whether these three things are separate or inter-related and if so, what is the chain of command,' said Professor Walker.
'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.' Dr Simon Ridley, Head of Research at Alzheimer's Research UK, the UK's leading dementia research charity, said: 'This small study makes a link between structural changes in the brain, sleep quality and memory in old age, but further investigation is needed to confirm the nature of this association.
'Increasing evidence has linked changes in sleep to memory problems and dementia, but it's not clear whether these changes might be a cause or consequence. The people studied here were followed for a very short period, and one next step could be to investigate whether a lack of 'slow-wave' sleep may also be linked to a long-term decline in memory.
'The people in this study did not have dementia, but understanding the different factors that influence our brain health as we age could be crucial in the fight against the condition. With 820,000 people affected by dementia, it's vital that we invest in research to find better treatments and ways to prevent the condition.'