A new study suggests that enhancing the brain's natural waste-clearing system during sleep may help prevent or slow Alzheimer's disease. Researchers used an innovative in-ear wearable device to measure the glymphatic system, a network of biological channels around blood vessels that clears toxic proteins from the brain. The findings, published in Nature Communications, show that good sleep promotes the clearance of amyloid and tau proteins, the hallmark proteins linked to Alzheimer's and other dementias.

What Is the Glymphatic System and Why Does It Matter?

The glymphatic system was discovered in 2012 and functions as the brain's internal plumbing system. Scientists have long known from animal studies that this system works primarily at night, actively flushing out waste products that accumulate during waking hours. However, tracking this system in living humans has been challenging until now. The new research provides some of the first direct evidence that this cleaning mechanism is linked to Alzheimer's protein clearance in people.

Dr. Paul Dagum, CEO and co-founder of Applied Cognition, explained the significance of the discovery. "How 'Brain Cleaning' While We Sleep May Lower Our Risk of Dementia," he noted, emphasizing that enhancing waste clearance in the brain may help treat Alzheimer's. The team's research suggests that if we could boost the brain's internal waste clearance mechanisms, the body could potentially do the job on its own, reducing the need for external interventions like anti-amyloid drugs.

Paul Dagum, CEO and co-founder of Applied Cognition

How Did Researchers Measure Brain Waste Clearance?

The study recruited 39 healthy adults around age 60 and had each participant undergo one night of normal sleep and one night of disrupted sleep. Participants wore an in-ear device developed by Applied Cognition that records brain waves to assess sleep quality, how well the brain's blood vessels are pumping, and how easily fluid-carrying waste can flow within the brain. Researchers collected blood samples to measure Alzheimer's biomarkers each night and in the morning.

The device measures three critical factors that must align for the glymphatic system to function properly:

• Sleep Quality: The device records brain wave patterns to determine how deeply and restfully a person is sleeping.
• Blood Vessel Function: It assesses how well the brain's blood vessels are pumping blood and delivering oxygen to brain tissue.
• Fluid Flow: It measures how easily cerebrospinal fluid, which carries waste products, can flow through the brain.

In the morning, the levels of tau and beta-amyloid biomarkers rose in the blood. Importantly, the biomarkers increased more after a good night of sleep and less after disrupted sleep. Together with the data modeling glymphatic flow, the results suggest that good sleep promotes waste clearance in healthy older adults.

What Do These Findings Mean for Alzheimer's Prevention?

The research aligns with previous findings showing that healthy sleep is crucial to clearing Alzheimer's-linked proteins. A 2018 study demonstrated this effect using gold-standard imaging techniques, while a 2025 study used cerebrospinal fluid biomarkers. However, Dagum's team is the first to investigate whether the glyphatic system itself is responsible for this protein clearance.

Dr. Tracy Butler, a neurologist and neuroscientist at Weill Cornell Medicine, acknowledged the innovation but urged caution. "The study uses a very cool new experimental device, worn in both ears, that measures resistance through the brain, as well as EEG and other measures, to provide an estimate of brain glymphatic clearance," she explained. However, she noted that since the researchers used proxies to measure both glymphatic flow and Alzheimer's proteins, we cannot be completely certain that the changes reflect glymphatic clearance of these proteins during sleep.

Despite these caveats, the implications are significant. If the glymphatic system can be enhanced, it could offer a new approach to Alzheimer's treatment that works with the body's natural mechanisms rather than relying solely on drugs to remove amyloid plaques from the brain.

How Can You Support Your Brain's Natural Waste Clearance?

While researchers continue to develop targeted treatments, there are evidence-based steps you can take now to support your brain's natural cleaning processes:

• Prioritize Deep Sleep: Aim for 7 to 9 hours of quality sleep each night, as the glymphatic system is most active during deep sleep stages when the brain can fully engage in waste clearance.
• Exercise Regularly: Physical activity boosts blood flow to the brain and may enhance glymphatic function. Dr. Butler noted that "one simple way to probably boost clearance that is good for you anyway is exercise."
• Maintain Consistent Sleep Schedules: Going to bed and waking up at the same time each day helps regulate your body's natural rhythms and may optimize glymphatic system function.

Dagum's team is now planning a follow-up study at Washington University in St. Louis using these measures in people with early Alzheimer's disease. Additionally, Dagum is publishing results from a trial using a fixed dose combination of two drugs, dexmedetomidine (a sedative) and midodrine (to increase blood pressure), to modulate glymphatic flow in healthy people. If successful, this could pave the way for clinical trials in people with early Alzheimer's.

The discovery of the glymphatic system's role in clearing Alzheimer's proteins represents a paradigm shift in how scientists think about the disease. Rather than focusing solely on removing amyloid plaques after they accumulate, researchers are now exploring how to enhance the brain's own waste-clearing machinery. As this research continues, optimizing sleep quality and exercise may be among the most accessible and effective strategies for supporting brain health and potentially reducing dementia risk.