Wednesday, June 3rd 2026
During deep sleep, the brain activates a natural cleaning system that removes harmful proteins and can reduce the risk of dementia and neurodegenerative diseases
While we sleep, our brain doesn’t just rest from the day’s activities. On the contrary, at night, a complex “cleaning” system is activated, which removes harmful substances accumulated during the day. Researchers now believe that this very process may play a key role in protecting against dementia and other neurodegenerative diseases.
Why is sleep so much more than rest?
A new scientific analysis, published in the journal Science, shows that sleep disorders, chronic stress, depression, cardiovascular disease and aging have one thing in common: they can disrupt the brain’s natural rhythms that, during sleep, allow waste to be removed. metabolic.
It has long been known that adults need an average of seven to eight hours of sleep to maintain physical and mental health. However, new findings show that sleep is not only a period of recovery for the organism.
During the deep stages of sleep, the brain activates the so-called glymphatic system, a network charged with removing harmful proteins and other waste products that accumulate while we are awake.
According to the author of the study, neurologist dr. Maiken Nedergaard from the University of Rochester Medical Center, more and more evidence shows that the disorder of this system can be an important factor in the development of neurodegenerative diseases, Telegraph reports.
During the day, different neurotransmitters, including noradrenaline, serotonin, dopamine and acetylcholine, act relatively independently and help maintain attention, mood and cognitive functions.
During sleep, the situation changes. These chemicals begin to act in sync, creating rhythmic patterns that stimulate the brain’s clearing process. Of particular importance are the stages of non-REM sleep, namely deep sleep, which sleep monitoring applications often mark as “core” or “deep sleep”.
During these stages, short bursts of brain activity, known as microwakes, occur. Although the person remains asleep, these brief events trigger a series of physiological changes.
They cause small blood vessels to dilate and constrict, promoting the movement of cerebrospinal fluid through the brain tissue. In this way, potentially harmful proteins are removed from the brain, including beta amyloid and tau protein, which are considered among the main signs of Alzheimer’s disease.
When sleep is interrupted or insufficient, the brain’s natural rhythms are disrupted. The result is less efficient waste removal, which can accumulate over time.
Today experts are increasingly talking about the two-way connection between sleep and dementia. On the one hand, poor sleep can accelerate the accumulation of neurotoxic proteins and promote inflammatory processes in the brain. On the other hand, the early changes associated with neurodegenerative diseases often disrupt the very structure of sleep.
Thus a vicious circle is created, where disordered sleep worsens even more the processes that lead to brain cell damage.
Heartbeat as a new indicator of brain health?
One of the most interesting conclusions of the research is related to the variability of the heart rhythm during sleep. It is about the small differences in the time interval between two consecutive heartbeats.
Researchers have noticed that this parameter is closely related to the slow physiological rhythms that coordinate the processes of brain cleaning.
According to them, the greater variability of the heart rate during sleep may indicate better quality deep sleep and more efficient functioning of the glymphatic system.
If future research confirm this connection, simple heart rate monitoring may become an accessible and non-invasive way to early identify people at increased risk for cognitive decline and dementia.
However, experts warn that additional research is needed, as heart rate variability is influenced by many factors, including stress, physical condition, drugs and heart disease.
How to improve nocturnal rhythms
Although science is still investigating all the details of this complex process, experts emphasize that the recommendations for maintaining brain health are very similar to the general advice for quality sleep.
Going to sleep and waking up at approximately the same times, getting enough sleep, daily physical activity and stress control are the basic steps towards healthier sleep.
Also recommended avoiding stimulants in the evening hours, as well as reducing exposure to the strong light of screens before bedtime.
More and more research confirms that quality sleep is not a luxury, but a biological need that directly affects the health of the brain.
During the night, our nervous system performs a complicated job: it removes harmful substances that, if accumulated, can contribute to the development of dementia.
Therefore, experts estimate that maintaining healthy sleep habits can be one of the most important and most accessible ways for long-term maintenance of cognitive functions and reducing the risk of neurodegenerative diseases.
Source: prizrenpost
