What if poor sleep was doing more than just making you tired?
Researchers have discovered that disrupted sleep in older adults interferes with the brain’s ability to clean out waste, leading to memory problems and increasing the risk of neurological diseases like Alzheimer’s.
Poor Sleep and Brain Waste Removal
Poor sleep in older adults may interfere with the brain’s ability to clear out waste, according to researchers at The University of Hong Kong (HKU). A recent study, led by Professor Tatia M.C. Lee, Chair Professor of Psychological Science and Clinical Psychology and May Professor in Neuropsychology at HKU, explores how sleep quality affects brain function.
Previous research has linked poor sleep to cognitive decline. Professor Lee’s team focused on the glymphatic system, a network responsible for flushing out waste from the brain. This system plays a crucial role in maintaining brain health, especially as people age.
Sleep, Memory Decline, and Neurological Disorders
The researchers examined how disruptions in the glymphatic system might contribute to memory decline in poor sleepers. When this system malfunctions, harmful proteins accumulate in the brain, a process linked to neurological disorders like Alzheimer’s, Parkinson’s, and epilepsy.
“Sleep quality, brain activities, and glymphatic functioning are related. Understanding how sleep quality influences the glymphatic system and human brain networks offers valuable insight into the neurophysiological mechanisms underpinning age-related memory change,” Professor Lee said.
Study Findings: Poor Sleep Disrupts Brain Function
The research team studied 72 older adults using functional MRI scans and sleep recordings. The findings indicate that poor sleep quality adversely affects normal brain function by deactivating the restorative glymphatic system. “The results clearly reveal the effect of sleep on the human brain’s network through the glymphatic system, which in turn affects memory performance in older adults,” said Professor Lee. “Therefore, maintaining efficient glymphatic functioning seems crucial for promoting healthy aging.”
The Link Between Sleep and Cognitive Health
The results of the study add important evidence that sleep quality affects cognitive health through the underlying neural relationships. “Impaired memory is a common complaint among older adults with poor sleep quality,” Professor Lee noted. “Our results provide a novel perspective on the interplay between sleep, the glymphatic system, and multimodal brain networks.”
Reference: “Effects of sleep on the glymphatic functioning and multimodal human brain network affecting memory in older adults” by Junji Ma, Menglu Chen, Geng-Hao Liu, Mengxia Gao, Ning-Hung Chen, Cheng Hong Toh, Jung-Lung Hsu, Kuan-Yi Wu, Chih-Mao Huang, Chih-Ming Lin, Ji-Tseng Fang, Shwu-Hua Lee and Tatia M. C. Lee, 14 October 2024, Molecular Psychiatry.
DOI: 10.1038/s41380-024-02778-0
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2 Comments
The issue is not getting enough sleep. The issue is optimizing brain circulation. And the way most people sleep is causing poor brain circulation.
I am a medical anthropologist researcher and author. I have studied sleep position in relation to brain circulation, and the fact is that brain circulation is poor when lying down. This is due to the effect of gravity on our circulation.
Gravity helps drain fluid from the brain when we are standing, and resists blood flow to the brain, since the head is above the heart. But when we lie down, this gravity relationship changes, as the head and heart are on the same level. This results in loss of a gravity effect and consequent reduced drainage of fluid from the brain, and increased pressure to the brain. The heart is pumping directly into the brain without any gravity resistance. (This is why bleeding strokes, when blood vessels break from pressure, usually happen in the night, when people are lying down.) The result is an overall increased brain pressure with reduced brain circulation, since the pressure is up while the drainage is down. This impacts various brain structures, lowers the sugar and oxygen available to the brain, and increases waste product accumulation.
The effect of gravity on brain circulation is studied in space medicine, since astronauts have to deal with zero gravity, which is simulated in research on Earth by having people lie flat. Research has shown that elevating the head of the bed 30 degrees is optimal for brain and heart circulation.
We did a study on this and found that migraines are eliminated when you start elevating the head of the bed from 10-30 degrees. Head of bed elevation is already used to treat sleep apnea, glaucoma, GERD, asthma, and to reduce sinus congestion. This is why hospital beds are able to be elevated.
Unfortunately, sleep medicine, and this article, ignore sleep position. They call for more sleep, but if you are sleeping too flat, it will hurt more than help. You need to sleep the correct way for optimal brain circulation, and to minimize compression injuries to your body. We believe this also helps prevent dementia, which we think is the result of a lifetime of sleeping too flat. I’ve written about this in my article, Heads Up! The Way You are Sleeping May Be Killing You! https://www.academia.edu/1483361/Heads_Up_The_Way_You_Are_Sleeping_May_Be_Killing_You_
Makes sense – who else is studying the issue?