Research published Wednesday from University of California, Berkeley, sleep scientists suggests that deep sleep might help alleviate some of dementia’s most devastating outcomes. (Graphic by Neil Freese. Unsplash images courtesy Peyman Farmani, Nigel Tadyanehondo, Zoe Gayah Jonker and Yan Berthemy)
A deep slumber might help buffer against memory loss for older adults facing a heightened burden of Alzheimer’s disease, new research from the University of California, Berkeley, suggests.
Deep sleep, also known as non-REM slow-wave sleep, can act as a “cognitive reserve factor” that may increase resilience against a protein in the brain called beta-amyloid that is linked to memory loss caused by dementia. Disrupted sleep has previously been associated with faster accumulation of beta-amyloid protein in the brain. However, the new research from a team at UC Berkeley reveals that superior amounts of deep, slow-wave sleep can act as a protective factor against memory decline in those with existing high amounts of Alzheimer’s disease pathology — a potentially significant advance that experts say could help alleviate some of dementia’s most devastating outcomes.
“With a certain level of brain pathology, you’re not destined for cognitive symptoms or memory issues,” said Zsófia Zavecz, a postdoctoral researcher at UC Berkeley’s Center for Human Sleep Science. “People should be aware that, despite having a certain level of pathology, there are certain lifestyle factors that will help moderate and decrease the effects.
“One of those factors is sleep and, specifically, deep sleep.”
Zsófia Zavecz (Photo courtesy Zsófia Zavecz)
The research, published Wednesday in the journal BMC Medicine, is the latest in a large body of work aimed at finding a cure for Alzheimer’s disease and preventing it altogether.
As the most prevalent form of dementia, Alzheimer’s disease destroys memory pathways and, in advanced forms, interferes with a person’s ability to perform basic daily tasks. Roughly one in nine people over age 65 have the progressive disease — a proportion that is expected to grow rapidly as the baby boomer generation ages.
In recent years, scientists have probed the ways that deposits of beta-amyloid associate with Alzheimer’s disease and how such deposits also affect memory more generally. In addition to sleep being a foundational part of memory retention, the team at UC Berkeley previously discovered that the declining amount of a person’s deep sleep could act as a “crystal ball” to forecast a faster rate of future beta-amyloid buildup in the brain, after which dementia is more likely set in.
Years of education, physical activity and social engagement are widely believed to shore up a person’s resilience to severe brain pathology — essentially keeping the mind sharp, despite the decreased brain health. These are called cognitive reserve factors. However, most of them, such as past years of education or the size of one’s social network, cannot be easily changed or modified retroactively.
That idea of cognitive reserve became a compelling target for sleep researchers, said Matthew Walker, a UC Berkeley professor of neuroscience and psychology and senior author of the study.
“If we believe that sleep is so critical for memory,” Walker said, “could sleep be one of those missing pieces in the explanatory puzzle that would tell us exactly why two people with the same amounts of vicious, severe amyloid pathology have very different memory?”
