Deep sleep can protect the brain from memory loss and slow the progression of Alzheimer's disease, according to an international study of 60 patients.
Researchers tracked patients with mild to moderate Alzheimer's disease over three years to examine how nighttime brain activity and neurotransmitter levels influenced cognitive decline. The findings were published in the medical journal Neurology.
During the three-year observation period, scientists registered nighttime brain waves and measured levels of orexin. Orexin is a chemical messenger in the brain that maintains wakefulness and normally drops during sleep.
Orexin plays a central role in controlling arousal and the sleep-wake cycle. Deep sleep, which occurs during the slow-wave stage of rest, allows the brain to clear metabolic waste and consolidate memories.
Role of orexin in memory decline
The study revealed that patients with higher levels of orexin suffered faster deterioration in memory, thinking abilities, and overall mental state.
However, patients who exhibited more pronounced deep sleep brain waves experienced a weaker negative impact from elevated orexin levels. Scientists said quality deep sleep helps reduce activity in the orexin system, making the brain more resistant to processes associated with Alzheimer's disease development.
Alzheimer's disease is a progressive neurodegenerative condition that destroys memory and thinking skills over time. It is the most common cause of dementia worldwide, characterized by abnormal protein accumulations in brain tissue.
Insomnia medications and future treatments
The authors noted that medications designed to lower orexin activity are already used to treat insomnia. These same drugs are currently being studied as a potential treatment against Alzheimer's disease.
Improving the quality of deep sleep could become one of the ways to slow the progression of the disease, according to the research team.
In separate research previously reported by scientists, pathological proteins associated with Alzheimer's disease were found to be capable of transmission through donor blood.
