Berkeley study shows deep sleep reduces memory loss in Alzheimer’s

Sleep scientists at the University of California, Berkeley, have found that deep sleep, also known as non-REM sleep, may prevent memory decline in older adults with a high prevalence of Alzheimer’s disease. However, this new study suggests that higher levels of deep sleep act as a cognitive preservative factor, increasing the effects of beta-amyloid protein on memory loss. By practicing good sleep hygiene, older adults may be able to benefit from this compensatory function against Alzheimer’s disease.

University of California, Berkeley Sleep scientists say deep sleep may help alleviate some of the most devastating consequences of dementia.

Deep sleep may help prevent memory decline in older people Alzheimer’s disease Disease pathology acting as a cognitive reserve factor to the effects of beta-amyloid protein. Good sleep hygiene may have benefits against the pathology of Alzheimer’s disease.

Deep sleep may help ease memory loss in older adults facing the burden of Alzheimer’s disease, suggests new research from the University of California, Berkeley.

Deep sleep, also known as non-REM sleep, may act as a ‘cognitive reserve factor’ that may increase resilience against a protein in the brain called beta-amyloid, which is associated with memory loss from dementia. Disturbance has previously been associated with faster accumulation of beta-amyloid protein in the brain. It has been shown that it may act as a protective factor against memory loss in patients with advanced disease. It helps alleviate some of the most devastating consequences of dementia.

Zsófia Zavecz, a postdoctoral fellow at the Center for Human Sleep Sciences at the University of California, Berkeley, said: “People should be aware that even with some degree of medical condition, there are certain lifestyle factors that can help mitigate and lessen its effects.

“One of those factors is sleep, especially deep sleep.”

A study published in the journal on May 3, 2023 BMC Medicine, It’s the latest in a large body of research aimed at finding a cure for Alzheimer’s disease and preventing it altogether.

The most common forms of dementia include Alzheimer’s disease disrupts memory pathways And in advanced forms, it interferes with a person’s ability to perform basic daily tasks. Approximately 1 in 9 women over the age of 65 have progressive disease, and this proportion is expected to increase rapidly as baby boomers age.

In people with similar accumulations of beta-amyloid protein, deeper sleep was associated with improved memory function. Credit: Illustration courtesy of Matthew Walker

In recent years, scientists have investigated how beta-amyloid deposits are associated with Alzheimer’s disease and how such deposits are associated. Affects memory more generallyIn addition to sleep being a fundamental part of memory retention, a team at the University of California, Berkeley has previously found that a person’s reduced amount of deep sleep “crystal ball” It predicts a faster rate of future beta-amyloid accumulation in the brain that makes dementia more likely to develop.

Years of education, physical activity, and social engagement widely believed To enhance a person’s resilience to serious brain pathologies – essentially keeping the mind sharp despite declining brain health. However, most things like years of education in the past and the size of his social network cannot be easily changed or retroactively corrected.

This idea of ​​cognitive reserve has become an attractive target for sleep researchers, says Matthew Walker, professor of neuroscience and psychology at the University of California, Berkeley, and senior author of the study.

“If we believe that sleep is so important for memory, it could be one of the missing pieces of the explanatory puzzle that explains exactly why two people with the same amount of bad and severe amyloid lesions are so different. Is there memory?”

“If the findings support the hypothesis, that’s thrilling, because sleep is something we can change,” he added. “It’s a modifiable factor.”

To test that question, researchers recruited 62 older adults from the Berkeley Aging Cohort Study. Participants, who were healthy adults and had not been diagnosed with dementia, slept in the lab while researchers monitored their sleep waves with an electroencephalograph (EEG) machine. The researchers also used positron emission tomography (PET) scans to measure the amount of beta-amyloid deposits in the participants’ brains. Half of the participants had massive amyloid deposits. I didn’t do the other half.

After going to bed, participants completed a name-to-face memory task.

People with large amounts of beta-amyloid deposits in the brain and high levels of deep sleep also performed better on memory tests than those with the same amount of beta-amyloid deposits but poor sleep. was limited to a group of In the no-pathology group, deep sleep had no additional supportive effects on memory.

In other words, deep sleep bent the cognitive arrow upwards and blunts the detrimental effects of β-amyloid pathology on memory.

In their analysis, the researchers continued to control for other cognitive preparatory factors, including education and physical activity, and still showed significant benefits for sleep. It has been suggested that it contributes to the recovery of memory function in the face of brain pathologies. These new findings demonstrate the importance of non-REM slow-wave sleep in counteracting some of the memory-impairing effects of beta-amyloid deposits.

Walker likened deep sleep to rescue operations.

“Think of deep sleep as a life raft that allows memories to surface instead of being dragged down by the weight of Alzheimer’s disease,” said Walker. “Now it seems that deep non-REM sleep may be another missing piece in the puzzle that explains cognitive reserve, which is particularly exciting. we can do something about it. There are ways to improve sleep, even for older people. ”

Who are the key areas for improvement? Adhering to a regular sleep schedule, staying mentally and physically active during the day, creating a cool, dark sleep environment, avoiding late-night coffee and screen time before bed. Taking a hot shower before going in the night has been shown to improve the quality of deep, restful sleep, says Zavecz.

Due to the small sample size of healthy participants, the study is only an early step in understanding exactly how sleep can forestall the progression of memory loss and Alzheimer’s disease, Zavecz said.

Still, it opens the door to potential long-term experiments examining sleep-improving treatments that could have far-reaching effects.

“One of the benefits of this result is that it applies to a huge population of people over the age of 65,” said Zavecz. “By doing your best to sleep better and practice proper sleep hygiene, which can be easily researched online, you can benefit from compensatory mechanisms for this type of Alzheimer’s disease.”

Reference: “Non-REM sleep as a new protective cognitive reserve factor in the face of Alzheimer’s disease pathology,” Zofia Zabez, Vioma D. Shah, Olivia G. Murillo, Rafael Valat, Bryce A. Mander, Joseph R. Winner, William J Jagust and Matthew P. Walker, 3 May 2023, BMCmedicine.
DOI: 10.1186/s12916-023-02811-z