The hidden threat of poor-quality sleep revealed

Night "cleaning": scientists reveal connection between sleep and protecting the brain from dementia

An international team of researchers has discovered that sleep may play a crucial role in cleansing the brain of toxins associated with the development of dementia. Scientists studied the glymphatic system — a natural mechanism for removing harmful substances from brain tissue, which is especially active during sleep. This is reported by The Conversation portal.

Unlike the rest of the body, where the lymphatic system is responsible for removing metabolic products, there are no classical lymphatic vessels in the brain. Only about ten years ago, scientists described an alternative cleaning pathway - the glymphatic system. It uses the circulation of cerebrospinal fluid, which penetrates the intercellular space of the brain, "washes away" waste, and removes it through venous structures.

Researchers are particularly interested in amyloid-beta - a protein whose accumulation leads to the formation of plaques characteristic of Alzheimer's disease. Animal experiments have shown that during sleep, the elimination of this protein from the brain increases. Studies involving humans have also found that amyloid-beta levels in cerebrospinal fluid rise during wakefulness and decrease during sleep.

However, the picture remains ambiguous. Recent experiments on mice have called into question the notion of "nighttime" activity of the glymphatic system, showing that its work can be intensive during the daytime as well. Scientists have not yet reached a consensus on the mechanisms of this process, especially as it applies to humans.

Nevertheless, data on the impact of sleep on brain health continues to accumulate. In one experiment, just one night of complete sleep deprivation in healthy adults led to an increase in amyloid-beta concentration in the hippocampus - a brain region critical for memory and one of the first to be affected by Alzheimer's disease. This indicates that sleep may indeed be associated with the removal of toxins from the brain.

Special attention is paid to chronic sleep disorders. For example, obstructive sleep apnea, in which breathing during sleep is repeatedly interrupted, is accompanied by prolonged sleep deprivation and decreased oxygen levels in the blood. Both factors may contribute to the accumulation of toxic proteins in the brain. Sleep apnea is already linked to an increased risk of dementia, and treatment of this disorder, as some studies show, improves the elimination of amyloid-beta.

Insomnia - another common sleep disorder - is also associated with a higher risk of dementia, but there is insufficient data on whether treating insomnia reduces the accumulation of neurotoxins. Researchers emphasize that at this stage, it is too early to claim that therapy for sleep disorders directly prevents dementia specifically by activating the glymphatic system.

In general, scientists agree that quality sleep is important for brain health and likely participates in its "cleaning" processes. However, the question remains whether improving sleep can purposefully reduce the risk of neurodegenerative diseases. Research continues, including analysis of daily fluctuations of amyloid-beta and tau protein in the blood of people with sleep apnea before and after treatment, as well as trials of drugs for insomnia therapy that can potentially affect nighttime brain function.

For now, specialists advise treating sleep as an important element of overall health and consulting a doctor if you have problems with sleep or memory, without waiting for serious symptoms to appear.