Delayed REM Sleep: Early Sign of Alzheimer’s Disease
Sleep is essential for both physical and mental well-being. Recent research highlights its importance in preventing diseases like Alzheimer’s. Both the quality and quantity of sleep play critical roles, with new findings suggesting that delayed REM (Rapid Eye Movement) sleep could be an early warning sign of Alzheimer’s disease.
What is REM Sleep?
REM sleep is the dream phase of the sleep cycle. It follows three progressively deeper stages of non-REM sleep, and the entire cycle takes about 90 minutes to complete. In a typical night, a person may go through this cycle four to five times. However, older adults often take longer to reach REM sleep.
During REM sleep, the brain consolidates emotionally charged memories and stores them in long-term memory. A disruption or delay in REM sleep can interfere with this process, potentially impairing learning and memory.
To learn more about REM sleep, check out this guide from Sleep Foundation.
The Link Between REM Sleep and Alzheimer’s
A recent study led by Yue Leng, PhD, at UCSF, investigated the connection between delayed REM sleep and Alzheimer’s. The study involved 128 participants, aged 70 on average, who were divided into three groups:
- People with Alzheimer’s.
- Those with mild cognitive impairment (a common precursor to Alzheimer’s).
- Individuals with normal cognition.
Participants stayed overnight in a clinic, where researchers measured their brainwave activity, eye movement, heart rate, and breathing.
Key Findings:
- Delayed REM Sleep: Participants who took longer to reach REM sleep (over 193 minutes) were more likely to have Alzheimer’s compared to those who reached it sooner (less than 98 minutes).
- Toxic Proteins: The delayed group had higher levels of amyloid and tau—proteins linked to Alzheimer’s. Specifically:
- 16% more amyloid.
- 29% more tau.
- Decreased Brain Health: They also had 39% less brain-derived neurotrophic factor (BDNF), a protein vital for memory and cognitive function.
For more on how Alzheimer’s develops, visit the Alzheimer’s Association website.
Why Delayed REM Sleep Matters
Dr. Leng explains that delayed REM sleep can disrupt the brain’s ability to consolidate memories, largely due to elevated cortisol levels (a stress hormone). High cortisol levels can impair the hippocampus, a brain region crucial for memory.
Tips for Healthy REM Sleep
Adopting healthy sleep habits can support the transition from light sleep to REM sleep, potentially lowering the risk of Alzheimer’s. Here’s what you can do:
1. Treat Sleep Disorders:
- Address conditions like sleep apnea, which can interrupt the sleep cycle. Learn more about sleep apnea and its treatment at the American Academy of Sleep Medicine.
2. Avoid Heavy Drinking:
- Alcohol can interfere with deep and REM sleep, so moderation is key.
3. Be Mindful of Medications:
- Some antidepressants and sedatives can reduce REM sleep. If concerned, consult your doctor.
4. Consider Melatonin:
- Melatonin supplements can boost REM sleep and, in animal studies, have been shown to reduce amyloid and tau accumulation. Find out more about melatonin’s benefits from NIH’s National Center for Complementary and Integrative Health.
5. Practice Good Sleep Hygiene:
- Maintain a regular sleep schedule.
- Create a relaxing bedtime routine.
- Ensure your sleep environment is dark, quiet, and comfortable. For more tips, check out CDC’s Sleep Hygiene Recommendations.
Sleep well, and take proactive steps to care for your mind and body!
