Beta-amyloid brain build-up
The research is from scientists at the Univ. of California at Berkley. What the research team knew going in is that rapid eye movement (REM) sleep is not only a necessary component to being well-rested, but also to having a healthy brain. It cleans out beta-amyloid proteins from the brain.
The beta-amyloid protein has been linked to Alzheimer’s Disease, and other dementia. Amyloid plaques are in healthy brains, but in small doses. However, when they build up in the brain, they stop neurons from firing and it’s believed that leads to memory loss and other results of dementia.
The more amyloid plaques build-up the more Alzheimer’s, the most common form of dementia, and other dementia, progresses. Eventually dementia kills, on average within eight to 12 years.
In the study, published in the journal Nature Neuroscience, researchers looked at 26 people between the ages of 65 and 83. None of the participants had previously been diagnosed with Alzheimer’s or with a sleep disorder.
Alzheimer’s Disease sleep study
First, the participants were given a positron emission tomography scan. The PET scan measured the amounts of beta-amyloid already in their brains. All 26 were then given 120 word-pairs to memorize and immediately tested on their retention of those word-pairs.
Their sleep that night was monitored and graphs were produced enabling researchers to learn of the quality of sleep they had obtained. After eight hours of sleep they were again tested on their retention of the same 120 word-pairs; further, their brains were scanned.
Neuroscientist Dr. William Jagust, a part of the study, said in a press release that they found participants who slept the poorest had the highest amounts of beta-amyloid in their brains. Further, those participants also did the poorest when trying to remember the word-pairs.
“Over the past few years, the links between sleep, beta-amyloid, memory, and Alzheimer’s disease have been growing stronger,” Dr. Jagust wrote. “Our study shows that this beta-amyloid deposition may lead to a vicious cycle in which sleep is further disturbed and memory impaired.”
Sleep clears out protein
Dr. Matt Walker, lead author of the study, said the results show hope for unlocking the mystery behind Alzheimer’s Disease. The researcher says that there is no doubt now that there’s a link between sleep, memory. the beta-amyloid protein and Alzheimer’s Disease.
“The more beta-amyloid that you have in certain parts of your brain the less deep sleep you get and, consequently, the worse your memory,” Walker said. “Additionally, the less deep sleep you have, the less effective you are at clearing out this bad protein. It’s a vicious cycle.
“But we don’t yet know which of these two factors – the bad sleep or the bad protein – initially begins this cycle,” he added. “Which one is the finger that flicks the first domino, triggering the cascade?”
Dr. Walker said their discovery “offers hope” and they will do more research in the area of sleep and Alzheimer’s and other forms of dementia. “Sleep could be a novel therapeutic target for fighting back against memory impairment in older adults and even those with dementia,” he said.
There are 44 million people worldwide with dementia and estimates vary as to how many die each year, with numbers varying between one million and 1.7 million. It is the 29th leading cause of premature death on the planet and is growing, with a new case every four seconds.
