Overview
Millions of people all over the world suffer from neurodegenerative diseases like dementia.[1]
More often than not, these people experience sleep loss many years before obvious signs of dementia start to creep in.
This intriguing yet conspicuous relationship between sleep problems and cognitive decline has led many scientists to question whether better sleep can help prevent or delay neurodegeneration.
In a new study, American researchers investigated whether prioritizing deep sleep could be the secret to safeguarding your brain.[2]
They found that sleep problems can speed up neurodegeneration, and improving sleep can help prevent cognitive decline.
Let us take a closer look at this fascinating study together!
Sleep and the Brain's Health
Before we dive into the study, it is imperative to understand the impact of sleep on the brain's health.
Sleep is far from a simple "off switch" for the brain. It's an active, highly organized process that orchestrates memory consolidation, metabolic detox, and emotional recalibration.[3] Think of it as nightly upkeep for the most sophisticated machine of your body.
One of the most essential things that sleep does is bring you back to balance after a long day of being awake.
When awake, our neurons are busy processing information, learning, and remembering. It costs something to do that, though.
Metabolic waste builds up during the day. Sleep, especially slow-wave sleep (SWS), helps the brain recover and clears out waste from metabolism.[3]
The Aging Brain and Sleep Crises
Sleep changes as we age. Usually, the amount of time spent in deep sleep drops, the length of sleep shortens, and sleep becomes more fragmented.[4]
Changes in sleep patterns as we age can affect memory and raise the risk of brain diseases.
Problems with non-rapid eye movement (NREM) sleep, especially slow-wave sleep (SWS), are significant. They relate to the early development of amyloid-beta (Aβ) plaques and tau protein tangles.[5] These changes are signs of Alzheimer's disease.
Many neurodegenerative issues, like Parkinson's disease and Lewy body dementia, can cause sleep problems.[6] These issues often appear years before any cognitive signs show up.
Even with these links, it's still unclear whether sleep problems cause neurodegeneration, show early signs of disease, or do both.
Experts say that if we understood how sleep impacts brain health, we could stop or slow neurodegenerative diseases sooner.
The Sleep and Neurodegeneration Study
In an impressive study published in the Neuron Journal, researchers investigated how sleep interruptions may lead to cognitive decline by analyzing sleep patterns, molecular markers, and brain activity in animal and human models.[2]
They investigated sleep architecture, specifically NREM and REM sleep variations, and their effects on neurodegenerative pathways. They also examined how sleep helps clear metabolic waste, like tau and amyloid-beta protein. However, they found mixed evidence on whether sleep regularly boosts clearance efficiency.
The researchers studied how long periods of being awake and broken sleep change brain activity, inflammation, and balance. Studies on animals show that not getting enough sleep speeds up neurodegeneration. This process happens because it increases protein buildup and disrupts how neurons work.
The study also looked at how neurotransmitters such as orexin, dopamine, and acetylcholine affect disease progression and how they control sleep-wake patterns.
Researchers also looked into genetic factors that make people less likely to get enough sleep. They looked at versions of genes like APOE4, DEC2, ABCA7, and TREM2 to see what role they play in cognitive decline.
The Study's Key Insights
The study found that interrupted sleep can cause neurodegeneration. It can also be an early warning sign of cognitive problems.
Poor sleep is linked to higher levels of neurotoxic proteins. It reduces clearance and raises neural activity. These changes can lead to inflammation and oxidative stress.
The research found that early neurodegenerative changes were linked to fragmented sleep. This connection appeared in both human and animal models. It also showed a decrease in slow-wave sleep.
Genetically predisposed people, including APOE4 carriers, had more notable sleep problems and an increased risk of dementia.
Notably, different sleep patterns were observed for people with various neurodegenerative diseases. People with Alzheimer's disease had more sleep disruption. In contrast, Parkinson's disease and frontotemporal dementia were connected to REM sleep behavior disorder and excessive daytime sleepiness.
The study's findings indicate that improving sleep by behavioral adjustments, pharmacological interventions, or sleep therapy reduced neurodegenerative processes in experimental models. In animal models, increasing slow-wave sleep reduced amyloid load while improving cognitive function.
The scientists noted some limitations in their research. They couldn't determine how to distinguish causation from correlation in human studies.
They pointed out that neurodegeneration is tied to sleep problems. Still, more research is needed to determine if sleep treatments can help delay the disease's onset.
What You Can Do Today To Protect Your Brain
While we wait for better clinical tools and treatments, you can take easy steps to protect your brain starting tonight:
- Give sleep a priority; try for 7–9 hours of sound sleep each night.
- Keep a consistent sleep pattern, even on weekends.
- Before bed, cut back on screens and coffee.
- Tackle snoring, sleeplessness, or too much sleepiness could indicate underlying sleep problems.
- Stay active and engaged during the day. Physical and mental activity helps improve sleep quality.
- Don't dismiss inadequate sleep as "just getting older." It can be a warning sign. See your doctor early if you have sleep problems.
What's the Takeaway?
Sleep is not just a nightly habit. It's a necessary process that helps keep the brain healthy and prevents illness.
The study highlighted how crucial sleep is for the brain. It suggested that sleep problems might speed up neurodegeneration, not just happen alongside it.
Improving sleep quality, particularly deep sleep, may help prevent cognitive deterioration. More research is needed to confirm sleep-focused therapy in humans.
Still, focusing on sleep health might be key to reducing the risk of neurodegenerative diseases.
References
- Cao, Q., Tan, C. C., Xu, W., Hu, H., Cao, X. P., Dong, Q., Tan, L., & Yu, J. T. (2020). The Prevalence of Dementia: A Systematic Review and Meta-Analysis. Journal of Alzheimer's disease : JAD, 73(3), 1157–1166. https://doi.org/10.3233/JAD-191092
- Parhizkar, S., & Holtzman, D. M. (2025). The night's watch: Exploring how sleep protects against neurodegeneration. Neuron, 113(6), 817–837. https://doi.org/10.1016/j.neuron.2025.02.004
- Eugene, A. R., & Masiak, J. (2015). The Neuroprotective Aspects of Sleep. MEDtube science, 3(1), 35–40. https://pmc.ncbi.nlm.nih.gov/articles/PMC4651462/
- Klerman, E. B., & Dijk, D. J. (2008). Age-related reduction in the maximal capacity for sleep--implications for insomnia. Current biology : CB, 18(15), 1118–1123. https://doi.org/10.1016/j.cub.2008.06.047
- Han, Z., Yang, X., & Huang, S. (2024). Sleep deprivation: A risk factor for the pathogenesis and progression of Alzheimer's disease. Heliyon, 10(7), e28819. https://doi.org/10.1016/j.heliyon.2024.e28819
- Singh, H., & Sankari, A. (2024). Sleep and Neurodegenerative Disorders. In StatPearls. StatPearls Publishing. https://pubmed.ncbi.nlm.nih.gov/39163464/
