# Glymphatic system

The glymphatic system, described by Iliff, Nedergaard, and colleagues in 2012, is your brain's waste-clearance pathway. Cerebrospinal fluid flows along the spaces around blood vessels, swaps with the fluid between cells, and washes out metabolic waste, including beta-amyloid and tau. This clearance ramps up a lot during sleep (and under anesthesia in animals), when the space between brain cells widens by roughly 60% (Xie et al., 2013). When glymphatic clearance falters, it is implicated in Alzheimer's and other neurodegenerative diseases. That makes sleep a key point to protect your brain's longevity.

## Sources

- Xie L, Kang H, Xu Q et al.. (2013). Sleep Drives Metabolite Clearance from the Adult Brain. Science. https://doi.org/10.1126/science.1241224
- Iliff JJ, Wang M, Liao Y, Plogg BA, Peng W, Gundersen GA, Benveniste H, Vates GE, Deane R, Goldman SA, Nagelhus EA, Nedergaard M. (2012). A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid β. Science Translational Medicine. https://doi.org/10.1126/scitranslmed.3003748

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_Canonical: https://longevity-switzerland.com/en/glossary/glymphatic-system · Part of Longevity Cities · Updated 2026-06-22_