Poor quality sleep can increase the risk of Alzheimer’s disease, new research finds.
Even eight hours per night may not be enough for the brain’s waste removal system to work properly, if it is not deep sleep.
Fewer hours of high quality sleep are better than more lower quality sleep, the study found.
High quality sleep means more ‘deep sleep’: the type of sleep in which we do not dream.
During deep sleep the brain’s glymphatic system — which clears waste — works optimally.
The buildup of toxic proteins, called beta amyloid and tau, is critical to the progression of Alzheimer’s disease.
It occurs when the brain becomes less efficient at removing these toxic proteins.
For the study, mice were given various different anaesthetics that changed how they slept. The anaesthetic that put them into a deep sleep was linked to the best functioning of the brain’s waste management system.