In 2019, the world’s authoritative journal “Science” had published a study mentioned that during non-rapid eye movement sleep, the brain can stabilize memory and cognitive functions, at the same time, increase cerebrospinal fluid in the brain to clear metabolic waste products in the brain.

With the assistance of both blood and spinal fluid in the brain, toxins including beta amyloid can be removed.

The deposition of beta amyloid is an important cause of Alzheimer’s disease.

During the day, the brain uses a lot of energy for thinking, analysis, and other tasks which later produces a lot of metabolic waste. It’s just like using a computer from morning to night, it get slower and slower due to too much information.

Good sleep is like a cleaner. It can call out cerebrospinal fluid to remove unnecessary information and clear space, so that the brain can continue to function the next day. If the spinal fluid is reduced and the brain is not clean enough, the functioning of the next day will be hindered, memory and cognitive functions decline. Decreased cognitive function results in poor sleeping quality, difficult to go into deep sleep. Poor deep sleep reduces spinal fluid, and the brain will not be clean enough. This process keep continues and enters into a bad cycle.

Therefore, staying up all night can increase the risk of dementia because it is just like the brain did not clear out the trash of the day which leads to poor brain function.