Prolonged rapid eye movement (REM) sleep latency may serve as a potential marker for Alzheimer’s disease and related dementias, according to new research published on January 27, 2024, in the journal Alzheimer’s & Dementia. Conducted by Jiangli Jin and colleagues from the China-Japan Friendship Hospital, the study explored the connections between sleep patterns and Alzheimer's biomarkers among 128 participants.
The significance of REM sleep cannot be overstated; during this stage, the body undergoes key processes pivotal for learning and memory consolidation. Disruptions during this sleep phase may have repercussions for cognitive health — particularly concerning Alzheimer's, which afflicts millions.
Participants included 64 with diagnosed Alzheimer’s disease, 41 with mild cognitive impairment, and 23 who demonstrated normal cognitive abilities. The research team employed polysomnography alongside amyloid beta (Aβ) positron emission tomography (PET) and plasma biomarker analysis, targeting indicators such as phosphorylated tau protein at threonine 181 (p-tau181) and brain-derived neurotrophic factor (BDNF).
Notably, the study revealed those who experienced prolonged delays before entering REM sleep — over 193 minutes — showed elevated Aβ burden and p-tau181 levels, correlated with lower BDNF concentrations. The authors noted, "Prolonged REM latency was associated with key AD/ADRD pathophysiology, including elevated Aβ deposition and plasma p-tau181 and lower BDNF levels,” prompting questions about whether this may highlight early indicators of Alzheimer’s disease.
This research aligns with growing evidence connecting sleep disturbances to Alzheimer’s. Yue Leng, PhD, from the University of California San Francisco, emphasized, “The delay in REM sleep disrupts the brain’s ability to consolidate memories... If it is insufficient or delayed, it may increase stress hormone cortisol, impairing the hippocampus.”
The study suggests potential interventions, emphasizing the need to target REM latency as part of preventive measures against Alzheimer’s. According to Dantao Peng, MD, from the China-Japan Friendship Hospital, “Future research should study the effects of certain medications... this includes treating conditions like sleep apnea.”
Aside from medications, behavioral strategies may also prove beneficial. Health care professionals, especially pharmacists, can recommend over-the-counter supplements, such as melatonin, to improve REM sleep. Other lifestyle changes include reducing screen time before bed, maintaining healthy nutrition, and engaging the mind through activities like reading.
Addressing sleep quality not only contributes to well-being but seems to mitigate risks associated with cognitive decline. The link between insufficient REM sleep and Alzheimer’s was underscored by W. Christopher Winter, MD, who stated, “Poor sleep quality has been linked to Alzheimer’s disease... Conversely, individuals who sleep well, and get consistent amounts of sleep on schedule, seem to reduce their risk of cognitive impairment.”
To improve sleep patterns, experts suggest adhering to consistent sleep schedules, limiting caffeine and alcohol, and undertaking morning workouts to align with natural sleep-wake cycles. These simple interventions may promote not only healthier sleep but also offer protective factors against cognitive decline.
Improving REM sleep may be one of the keys to safeguarding memory function and staving off Alzheimer's, though much remains to be investigated. The potential of these findings marks the beginning of what might become significant clinical guidance for those at risk of dementia.
Consulting with medical professionals about sleep-related concerns is encouraged, particularly for those who may struggle to achieve restorative sleep. Following up with healthcare guidance can yield personal recommendations suitable for individual needs.
By prioritizing sleep hygiene, we can open the door toward cognitive resilience and promote lasting well-being as we age.