Poor sleep has been associated with the development of Alzheimer’s disease and other dementias. New research has shed light on why.
Investigators from Stanford University, Washington University School of Medicine, and the Netherlands’ Radboud University Medical School banded together to determine the effects of disrupted sleep and proteins linked to Alzheimer’s.
The results, published in the journal Brain, were startling: even one single night of poor sleep in otherwise healthy middle-aged subjects spikes levels of amyloid beta, a protein widely known to be tied to Alzheimer’s. Moreover, these scientists found that low-quality sleep for an entire week causes a surge in another separate protein – phosphorylated tau – also known to be associated with brain damage seen in Alzheimer’s disease and other neurodegenerative disorders.
"The implication of this research is that chronic poor sleep in the decades of the 30s, 40s, and 50s might increase the chances of Alzheimer’s disease later in life."
Previous research has shown that poor sleep increases the odds of cognitive problems. Persons with sleep apnea, for instance, have a heightened risk for developing mild cognitive impairment approximately 10 years earlier than healthy individuals.
In the current study, adults aged 35 to 65 with no history of insomnia or cognitive issues wore a home sleep monitor every night for up to two weeks. After baseline measures of total sleep time and quality of nightime sleep and daytime wakefulness were obtained, subjects were brought on site to the sleep lab. During this part of the study, half of the subjects were randomly selected to have their sleep artificially disturbed. Even though these individuals rarely remembered being awakened during the night, they reported feeling unrefreshed and fatigued.
Each of the subjects had a spinal tap to measure the levels of amyloid beta and tau in the CSF (cerebral spinal fluid).
After about a month or so this process was reversed; those who had their sleep disrupted the first time slept undisturbed while those who had slept uninterrupted initially were disturbed once they entered slow-wave, or deep, sleep.
Investigators then compared each subject's amyloid beta and tau levels after the disrupted nights to the levels after the uninterrupted nights. That's when they discovered that after a single night of interrupted sleep amyloid beta levels increaseed by 10%. Moreover, individuals whose sleep monitors showed they had slept poorly at home the week prior to the spinal tap showed a surge in levels of tau levels.
Millions of Americans suffer from Alzheimer’s disease and related disorders (ADRDs). Collectively, ADRDs is a group of conditions that cause a range of brain/mind disturbances from mild cognitive impairment through moderate to severe dementia. These potentially devastating conditions affect one’s functioning across multiple life domains: socially, personally, and professionally. As with other major medical disorders, Alzheimer’s disease begins long before symptoms start.
These diseases cause slow relentless memory loss, personality changes, disorganized behavior and other significant cognitive impairments. A consistent finding at autoposy of brains from patients with Alzheimer’s is the abnormal accumulation of amyloid beta protein plaques and clusters of tau protein. Together, these proteins cause one’s brain to shrink (atrophy) and eventually stop working.
We, in the medical community, have yet to discover a magic-bullet cure for Alzheimer’s and ADRDs. The good news is that simple preventative strategies can reduce the risk for ADRDs by as much as 50%. Among those all important simple strategies is making sure you get your 7-9 hours of sleep.
For other simple strategies, please refer to Dr. Dave's Top Ten Health Tips:
As pertains to sleep, a good starting point is to incorporate as many of the sleep hygiene habits listed in the graphic below. Additionally, safe, fast-acting, natural supplements are often helpful. And with that in mind, please be on the lookout for a new exclusive offering from Integrative Psychiatry, Inc. - Somniben, from TriNutra, the makers of our new PEA support product: Cogniben.
Holtzman et al. Slow wave sleep disruption increases cerebrospinal fluid amyloid-β levels. Brain, July 2017 DOI: 10.1093/brain/awx148Back