Alzheimer’s disease is marked by the presence of amyloid beta plaque, a specific kind of protein deposit in the brain. Formerly, researchers thought this deposit was the cause of the cognitive changes we associate with dementia. This year, new evidence changed this long-standing idea: the protein deposits in the brain are now viewed as a symptom of a dysfunction in brain clearance, rather than the cause.
The Glymphatic System
The glymphatic system is the waste clearance system of the brain, very similar to the lymphatic system for the body. It is a network of spaces in the central nervous system (brain and spine areas) which transport pathological waste products (including amyloid) to the lymphatic system to process and flush out of the body. The catch is that the glymphatic system is most active when we sleep. If we’re getting fewer hours of sleep than we need, our brain doesn’t fully flush all the toxins. That sleepy brain fog you get after a bad night’s sleep means your brain is sort of swimming in its own poop. The glymphatic system interfaces directly with the lymphatic system within the brain and then drains into the lymph nodes of the neck.
Reducing Amyloids
In addition to good sleep, researchers found that treating Alzheimer’s model mouse brains to gentle electric stimulation of 40hz (a specific frequency) increased the drainage clearance of amyloid from the glymphatic system.
Promising Path Forward
Although the effects of manual lymphatic drainage on Alzheimer’s dementia has not been specifically studied, it seems likely that using lymphatic intervention at the interface and exits of the glymphatic and lymphatic system would improve the removal of waste. The reduction in waste could have a positive effect in reducing dementia-like symptoms, and for preventing other cognitive issues caused by lymphatic accumulation in the brain; like brain fog, some ADHD symptoms, sleep disruptions, and hormonal disruptions.
- Jessen, N. A., Munk, A. S. F., Lundgaard, I., & Nedergaard, M. (2015). The Glymphatic System: A Beginner’s Guide. Neurochemical Research, 40(12), 2583–2599. https://doi.org/10.1007/s11064-015-1581-6
- Hablitz, L. M., & Nedergaard, M. (2021). The Glymphatic System: A Novel Component of Fundamental Neurobiology. the Journal of Neuroscience/the Journal of Neuroscience, 41(37), 7698–7711. https://doi.org/10.1523/jneurosci.0619-21.2021
- Murdock, M. H., Yang, C. Y., Sun, N., Pao, P. C., Blanco-Duque, C., Kahn, M. C., Kim, T., Lavoie, N. S., Victor, M. B., Islam, M. R., Galiana, F., Leary, N., Wang, S., Bubnys, A., Ma, E., Akay, L. A., Sneve, M., Qian, Y., Lai, C., . . . Tsai, L. H. (2024). Multisensory gamma stimulation promotes glymphatic clearance of amyloid. Nature. https://doi.org/10.1038/s41586-024-07132-6
- Huang, S., Zhang, Y., Guo, Y., Du, J., Ren, P., Wu, B., Feng, J., Cheng, W., & Yu, J. (2024). Glymphatic system dysfunction predicts amyloid deposition, neurodegeneration, and clinical progression in Alzheimer’s disease. Alzheimer’s & Dementia, 20(5), 3251–3269. https://doi.org/10.1002/alz.13789
- Boosting brain’s waste removal system could improve Alzheimer’s. (2021, May 11). National Institutes of Health (NIH). https://www.nih.gov/news-events/nih-research-matters/boosting-brains-waste-removal-system-could-improve-alzheimers-outcomes