According to recent research from the University of California, Berkeley, a good night's sleep may offer some protection against memory loss in older adults who are at an increased risk of developing Alzheimer's disease. The study found that deep, slow-wave sleep, also known as non-REM sleep, could act as a “cognitive reserve factor” and increase resilience against beta-amyloid, a protein linked to dementia-related memory loss. The researchers discovered that deep sleep could potentially act as a protective factor against memory decline in people with high levels of Alzheimer's disease pathology. This finding is crucial because disrupted sleep has previously been associated with faster accumulation of beta-amyloid protein in the brain.
Zsófia Zavecz, a postdoctoral researcher at UC Berkeley's Center for Human Sleep Science, stated that people with a certain level of brain pathology should be aware that lifestyle factors, such as sleep, can help moderate and decrease the effects of the disease. The study, published in the BMC Medicine journal, is part of ongoing efforts to find a cure for Alzheimer's disease and prevent it from occurring in the first place. Alzheimer's is the most common form of dementia and destroys memory pathways, making it difficult for individuals to perform daily activities. As the baby boomer generation ages, it is predicted that the proportion of people over the age of 65 with the disease will increase rapidly.
Over the years, scientists have investigated the relationship between deposits of beta-amyloid and Alzheimer's disease, as well as their effect on memory. UC Berkeley researchers found that decreased amounts of deep sleep could predict a faster rate of future beta-amyloid accumulation in the brain, leading to a higher likelihood of developing dementia. While education, physical activity, and social engagement can improve cognitive resilience, they are not easily modifiable. This led UC Berkeley professor Matthew Walker to explore whether sleep could be a modifiable cognitive reserve factor. The team recruited 62 older adults without dementia and monitored their sleep with an EEG machine, measured beta-amyloid deposits in their brains with a PET scan, and had them complete a memory task after sleeping.
Scientists have been studying how deposits of beta-amyloid in the brain affect memory and contribute to Alzheimer's disease. A team of researchers from UC Berkeley has discovered that a decline in deep sleep can predict a faster rate of beta-amyloid buildup and an increased risk of dementia. The team was interested in exploring the idea of cognitive reserve, which refers to factors like education, physical activity, and social engagement that can help protect the brain from severe pathology. They wondered if sleep could be another factor that contributes to cognitive reserve.
To test this hypothesis, the researchers recruited 62 healthy older adults who were not diagnosed with dementia. Half of the participants had high levels of beta-amyloid deposits in their brains, while the other half did not. The participants slept in a lab while researchers monitored their sleep waves with an EEG machine and used a PET scan to measure beta-amyloid deposits. After sleeping, the participants completed a memory task.
The researchers found that participants with high levels of beta-amyloid who experienced deeper levels of sleep performed better on the memory task than those who slept poorly. This boost in memory was not observed in the group without beta-amyloid deposits. The researchers controlled for other cognitive reserve factors like education and physical activity and found that sleep still had a significant positive effect on memory.
The researchers concluded that deep, slow-wave sleep can help counteract the memory-impairing effects of beta-amyloid deposits. They compared deep sleep to a life raft that keeps memory afloat in the face of Alzheimer's pathology. The study's findings suggest that improving sleep could be a way to protect against memory loss in older adults. The researchers recommended maintaining a regular sleep schedule, staying mentally and physically active during the day, creating a cool and dark sleep environment, and avoiding caffeine and screen time before bed. A warm shower before bed can also improve the quality of deep sleep.
Although the study had a small sample size, it opens the door for further research into sleep-enhancement treatments that could help protect against Alzheimer's. Improving sleep hygiene is an easy way for older adults to gain the benefits of this compensatory function.