Unexpected danger of poor sleep identified

Sleep may play a key role in "cleansing" the brain of toxins associated with the development of dementia. This conclusion was reached by an international team of researchers studying the work of the so-called glymphatic system - a mechanism for removing waste products from brain tissues, which is believed to work most actively during sleep. This is reported by The Conversation portal.

Unlike the rest of the body, where the lymphatic system is responsible for the elimination of metabolic products, there are no classical lymphatic vessels in the brain. Only about ten years ago, scientists described an alternative cleansing pathway - the glymphatic system. It uses the circulation of cerebrospinal fluid, which penetrates into 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 increase during wakefulness and decrease during sleep.

However, the picture remains ambiguous. Recent experiments in mice have called into question the idea of "nighttime" activity of the glymphatic system, showing that its operation can be intense 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 effect 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 the concentration of amyloid-beta in the hippocampus - a brain region critical for memory and one of the first to be affected in 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 syndrome, in which breathing during sleep is repeatedly interrupted, is accompanied by prolonged sleep deprivation and a decrease in blood oxygen levels. Both factors may contribute to the accumulation of toxic proteins in the brain. Sleep apnea is already associated with 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 data on whether insomnia treatment reduces the accumulation of neurotoxins is still insufficient. Researchers emphasize that at this stage it is too early to claim that therapy for sleep disorders directly prevents dementia precisely by activating the glymphatic system.

In general, scientists agree that quality sleep is important for brain health and probably participates in the processes of its "cleansing." However, the question remains whether it is possible to purposefully reduce the risk of neurodegenerative diseases by improving sleep. 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 general health and consulting a doctor if there are problems with sleep or memory, without waiting for the appearance of serious symptoms.