A common sleeping pill used to treat insomnia may offer unexpected benefits in the fight against Alzheimer's disease, according to promising research from Washington University in St. Louis. The study, published in the Annals of Neurology, reveals that suvorexant (marketed as Belsomra) temporarily reduces levels of harmful proteins associated with Alzheimer's development.
Researchers found that after just two nights of treatment, participants who received suvorexant showed a 10-20% reduction in amyloid-beta levels in their cerebrospinal fluid compared to those given a placebo. Higher doses (20mg) also reduced phosphorylated tau, a protein directly involved in forming the tangles that destroy brain cells, by approximately 10-15%.
"This is a positive sign," said Dr. Brendan Lucey, director of Washington University's Sleep Medicine Center and lead researcher on the study. "If you can reduce tau phosphorylation, potentially there would be less tangle formation and less neuronal death."
The Sleep-Alzheimer's Connection
Scientists have increasingly recognized the relationship between sleep quality and Alzheimer's risk. Poor sleep often appears years before cognitive symptoms emerge, suggesting it may be more than just a symptom of the disease.
During deep, restorative sleep, the brain engages in crucial maintenance processes, including clearing waste proteins like amyloid-beta and tau. When sleep is disrupted, these proteins can accumulate more rapidly, potentially accelerating disease progression.
Previous research has demonstrated that even a single night of poor sleep can cause amyloid-beta levels to spike. This new study takes that understanding further by showing that enhancing sleep quality through medication might actively reduce these harmful proteins.
Study Design and Findings
The Washington University team conducted a small but rigorous study involving 38 healthy adults between ages 45 and 65, with no existing sleep problems or cognitive impairment. Participants spent two nights at a sleep clinic, receiving either suvorexant or a placebo.
What makes this study particularly valuable is its methodology. Researchers collected cerebrospinal fluid samples every two hours through a small tube placed in participants' lower backs. This fluid, which surrounds the brain and spinal cord, carries waste proteins away from the brain and provides a direct measurement of amyloid-beta and tau levels.
The results showed significant reductions in both proteins after suvorexant administration. However, these effects were temporary, with tau protein levels returning to baseline within 24 hours after taking the medication.
How Suvorexant Works
Unlike traditional sleep medications that enhance sleep-promoting GABA pathways, suvorexant belongs to a newer class of drugs called dual orexin receptor antagonists (DORAs). Orexin is a neurotransmitter that promotes wakefulness; by blocking orexin receptors, suvorexant helps induce and maintain sleep.
Developed by Merck & Co. and approved by the FDA in 2014, suvorexant was specifically designed to address both sleep onset and maintenance issues. Its mechanism may be particularly beneficial for brain health, as it potentially allows for more natural sleep architecture, including the deeper sleep stages critical for waste clearance.
Limitations and Future Research
Despite the encouraging results, researchers emphasize several important limitations. The study was brief, lasting only two nights, and involved a relatively small sample of healthy middle-aged adults rather than individuals at higher risk for Alzheimer's.
Additionally, scientists remain uncertain whether temporarily lowering these proteins will translate to meaningful long-term protection against Alzheimer's disease. Previous clinical trials targeting amyloid-beta have successfully reduced protein levels but failed to improve cognitive outcomes in patients with established disease.
"It would be premature for people who are worried about developing Alzheimer's to interpret it as a reason to start taking suvorexant every night," Dr. Lucey cautioned. Long-term use of sleeping medications carries risks including dependence, tolerance, and potentially reduced sleep quality over time.
The research team plans to conduct longer studies lasting months rather than days to determine if sustained treatment produces more lasting effects. They also aim to test suvorexant in older adults who show early amyloid accumulation but have not yet developed cognitive symptoms.
Clinical Implications
This research highlights the potential of sleep-based interventions in Alzheimer's prevention strategies. If improving sleep quality can consistently reduce harmful protein accumulation, it could represent a relatively simple approach to reducing disease risk.
However, experts recommend focusing first on non-pharmacological approaches to sleep improvement. Maintaining regular sleep schedules, creating restful sleep environments, limiting screen time before bed, and addressing underlying sleep disorders like sleep apnea may all contribute to better brain health.
For those with persistent insomnia, medications like suvorexant might offer dual benefits—improving sleep while potentially reducing Alzheimer's risk factors. However, any medication decision should involve careful consideration of individual health factors and consultation with healthcare providers.
The Broader Context
This study adds to a growing body of evidence suggesting that lifestyle factors, including sleep quality, may significantly influence Alzheimer's risk. While genetic factors play an important role in disease susceptibility, modifiable factors offer opportunities for intervention.
The Alzheimer's research community has faced numerous disappointments in the search for disease-modifying treatments. Many promising drugs have failed in late-stage clinical trials, highlighting the need for diverse approaches to prevention and treatment.
Sleep-based interventions represent one such approach, potentially offering a complementary strategy alongside other emerging therapies. As Dr. Lucey notes, "I'm hopeful that we will eventually develop drugs that take advantage of the link between sleep and Alzheimer's to prevent cognitive decline."
For now, the message is clear: quality sleep matters for brain health. Whether through improved sleep habits, treatment of sleep disorders, or carefully considered medication use, prioritizing sleep may offer protection against one of medicine's most challenging diseases.
