April 9, 2018

expert reaction to study investigating sleep deprivation and amyloid build up

Researchers examine potential links between sleep deprivation and beta-amyloid build up in the human brain, in a new study, published in PNAS.

Prof Martin Rossor, NIHR National Director for Dementia Research, University College London Hospitals, said:

“We spend a lot of our lives asleep and being prevented from sleep causes many health problems . This study is important as it shows that a single night of sleep deprivation can lead to an increase in amyloid, a protein associated with Alzheimer’s disease, deposited in the brain.

The the study does not show how quickly this returns to normal (I have not seen the supplementary material and so cannot assess how severe the sleep deprivation was) and cannot be used to argue that sleep deprivation leads to Alzheimer’s disease. However like adequate exercise all the evidence suggests that adequate sleep is important for the brain and that is why we spend so much our lives asleep.”

Dr. Doug Brown, Chief Policy and Research Officer at Alzheimer’s Society, said:

“Sleep deprivation is a topic fascinating dementia researchers around the world. This study suggests that amyloid beta, the protein that builds up in the brains of people with Alzheimer’s, also builds when we’re deprived of sleep.

“Though several studies have suggested that amyloid beta builds up when we lack sleep, and previous evidence has shown sleep may give the brain a chance to clear out clumps of amyloid beta, unfortunately none have been able to confirm that sleep deprivation can cause dementia. This study can’t give us a definitive answer either, as it only looked at a very small number of people for a short period of time, none of whom had dementia.

“There’s still a lot of research to be done on the link between sleep and Alzheimer’s disease and with someone developing dementia every three minutes in the UK, it’s vital we continue to investigate possible causes. Our work at the UK Dementia Research Institute will accelerate discoveries into how we can prevent the condition – research will beat dementia.”

Prof Tara Spires- Jones, UK Dementia Research Institute Programme Lead and Deputy Director of the Centre for Discovery Brain Sciences, University of Edinburgh, said:

“In this study, Dr Shokri-Kojoriand colleagues examined the effect of sleep deprivation on the accumulation of amyloid beta, one of the pathologies that builds up in the brain of people with Alzheimer’s disease.  People who were sleep deprived for one night had slightly more of the label for amyloid beta in some parts of the brain than when they had a good night’s sleep.  This is an interesting study building on recent evidence that sleep is important for clearing amyloid beta from the brain.

“However, the study only looked at 20 people.  Another limitation of this study is that the method the scientists used to detect the amyloid beta has not been thoroughly tested for detecting the types of amyloid beta present in the brains of healthy people.  The method is proven to detect the large clumps of amyloid beta in Alzheimer’s disease patients’ brains but less is known about whether it is an accurate label for the smaller clumps that can occur in healthy people. Thus while this study is interesting, more work needs to be done to fully understand the relationship between sleep and Alzheimer’s disease.”

Dr David Reynolds, Chief Scientific Officer 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.

“The study doesn’t tell us how a good night’s sleep might keep amyloid levels at bay, while the researchers suggest that sleep helps clear the protein from the brain, other potential explanations also need to be explored. Finding out more about how the brain processes this protein will give researchers vital insights as they work towards ways limit the harmful amyloid build-up that we see in Alzheimer’s disease. Alzheimer’s Research UK is funding pioneering research to unravel the link between sleep and the amyloid protein, and it is an important area of research for scientists working at the UK Dementia Research Institute, the country’s largest ever initiative aimed at understanding the causes of dementia.

“While this study sheds more light on the link between sleep and amyloid, it only provides a snap-shot of brain changes after a single night of disturbed sleep and doesn’t tell us whether this short-term association is relevant for the development of Alzheimer’s long-term. The development of Alzheimer’s is a process that takes many years and is likely to depend on multiple genetic, health and lifestyle factors. There are a number of important health benefits linked to a good night’s sleep but we need to do more to unpick the potential long-term benefits of sleep on Alzheimer’s risk.”

* ‘β-Amyloid accumulation in the human brain after one night of sleep deprivation’ by name of Shokri-Kojori et al. published in PNAS on Monday 9 April.

Declared interests

Prof Martin Rossor: “No conflicts other than paid role of NIHR National Director for Dementia Research”

Prof Tara Spires-Jones: “I have no conflicts of interest with this study.”

Dr David Reynolds: No conflicts of interest.