While researching information on the brain and its need for cholesterol, I ran across a topic I'd never heard of before: the glymphatic system within the brain. That took me down a rabbit hole, which resulted in this substack.

The central nervous system (CNS) is the only organ in the entire body that lacks its own, defined lymphatic drainage system. As a result, the Great Architect created unique adaptations for achieving fluid balance and waste removal called the glymphatic system.

The glymphatic system, which is short for glial-dependent lymphatic transport, was only recently discovered  (2012). It is a waste clearance system that utilizes a unique system of channels formed by astrocytes to promote the elimination from the central nervous system (CNS).  

Importantly, the glymphatic system functions during sleep and is mostly quiet during wakefulness. The biological need for sleep across all species reflects that the brain must enter a state of inactivity. During sleep it eliminates neurotoxic waste products, including β-amyloid.  

In addition, the glymphatic system, and hence sleep, contributes to the reduction of brain lactate. The accumulation of lactic acid (lactate) in the brain promotes deposits of Aβ proteins, the main feature of Alzheimer's Disease. Excessive transmission of lactic acid into neurons in the brain leads to acidity (lactic acid quickly becomes lactate + hydrogen atoms [H+]). This acidic environment leads to mitochondrial function failure and cell death (apoptosis), both have an adverse impact on brain function. The mitochondria are the organelles that produce the energy (ATP) needed by all cells to live. All data presented within several reports support the notion that glymphatic clearance plays a key role in lowering brain lactate concentration and improves brain health.