Researchers from the US and the Netherlands have highlighted a link between disrupted sleep and levels of proteins involved in Alzheimer’s disease. The study, published today (Monday 10 July) in the journal Brain highlights that a lack of deep sleep could lead to more of these proteins building up in the brain.
The researchers in this study worked with 17 participants between the ages of 35 and 65 who had no existing memory and thinking problems or sleep disorders. They used wrist mounted activity monitors to measure how much sleep each participant had in the five to 14 days leading up to an overnight stay at the study centre. During the overnight stay, half of the participants had their sleep interrupted by a series of bleeps that were triggered when they entered deep – or slow wave – sleep. After a month, the experiment was repeated but with the other half of the participants undergoing the disrupted sleep. Following each overnight stay, the researchers measured levels of the hallmark Alzheimer’s proteins, amyloid and tau in the spinal fluid of each participant. These proteins are present normally in the human body, but in Alzheimer’s disease they build up into abnormal clumps in the brain.
They found that following an interrupted night’s sleep, the participants had an increase in the levels of amyloid protein in the spinal fluid. Less sleep in the days leading up to the overnight stay was linked to increases in levels of tau protein.
Dr Laura Phipps of Alzheimer’s Research UK, said:
“There is mounting evidence of a link between poor quality sleep and Alzheimer’s disease, but it is difficult to tease apart cause and effect in this relationship and determine whether sleep problems might cause Alzheimer’s brain changes or vice-versa. This very small study in younger people suggests lower quality sleep can trigger changes in the levels of proteins linked with Alzheimer’s, strengthening suggestions that sleep is important for the turnover of these proteins in the body. While this study sheds more light on the link between sleep and Alzheimer’s proteins, it doesn’t tell us whether this short-term association is relevant for the development of Alzheimer’s disease 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 further research is needed to unpick the potential long-term benefits of sleep on Alzheimer’s risk.”