Glymphatic System – Your Brain’s Private Contractor for Garbage Disposal

Does the g in glymphatic stand for garbage?

The Semi-long Introduction of the Glymphatic System

Your brain is one of the five essential organs needed for survival (heart, liver, kidneys, and lungs). Some would even argue that it’s the most vital organ in the human body.

Interestingly, your brain to body mass ratio is 1:40, which makes the brain around 2% of your body’s mass. What you might be surprised about is that it receives 15% of the total blood (approximately 750ml/minute) coming from the heart and uses approximately 20% of your body’s total energy reserves for it to function optimally. It’s a real wonder how such a small organ can receive so much blood and use a tremendous amount of energy. Those percentages don’t factor in too much thinking on your part, just the routine metabolic processes that take place in it.

When your brain cells require a lot of raw materials and utilise tremendous amounts of energy, they spew out a lot of waste products that bathe your brain, hindering it from functioning optimally. These waste products or brain debris are mostly proteins that are by-products of biochemical processes. Unfortunately, these proteins can clump together and cause harm to your brain.

An example of one of these leftover proteins is beta-amyloid. Beta-amyloid in clumps has been associated with Alzheimer’s disease. They have been suspected of decreasing brain functions like cognition and memory in persons with Alzheimer’s disease.

All of these leftover proteins and clumped proteins have to go somewhere. Enter the glymphatic system.

The Brain’s Private Contractor for Garbage Disposal

Several years ago (before 2012), your brain was thought of as not having its own waste disposal system unlike most of the organs in your body. The other organs in your body have the lymphatic system that acts as waste disposal. It’s made up of an interconnected series of small vessels that run through your body producing lymph fluid that cleans each organ. All the wastes are poured into a network of lymph ducts that ultimately drain into blood vessels where they’re mixed with blood. The blood passes through your liver and kidneys, where the wastes are disposed of from your body.

Little did neuroscientists and medical experts know that the brain has its own exclusive garbage disposal system. A group of researchers in 2012 from the University of Rochester Medical Centre in Rochester, New York have discovered that the brain has its own version of the lymphatic system. They discovered the following:

Cerebrospinal fluid (CSF) is the liquid around your brain and spinal cord. Its primary purpose was thought of as a cushion inside your skull preventing trauma to your brain. They found out that it also doubles as the lymph fluid of your brain. Using sophisticated imaging techniques on the brains of mice, they discovered and saw that CSF flowed into the brain and not just on the surface as was previously thought. They also documented that CSF swept away leftover and clumped proteins.
The CSF flowed into spaces that wrapped around small blood vessels that penetrate the substance of the brain. They found out that these spaces acted like gates for the entry of CSF. A group of supporting brain cells served as gatekeepers of these spaces. The supporting brain cells have sucking mechanisms that syphon CSF from the spaces and gets it in contact with brain cells (neurons). It collects proteins and other waste products and dumps it into lymphatic ducts.
Another function of the glymphatic system is the transport of lipophilic molecules (lipids) between supporting brain cells. This type of transport mechanism is similar to lymph vessels on the lining of your intestines (called lacteals) when they transport absorbed lipids from your digestive tract to the liver. The lipids also allow the supporting brain cells to communicate with each other.

Why Your Glymphatic System is Essential

Huntington’s disease, Parkinson’s disease, Amyotrophic lateral sclerosis, and Alzheimer’s disease are examples of neurodegenerative diseases. There’s a loss of neurons in these diseases that lead to sensory loss, memory decline, and cognitive impairment that worsen over time. They also fall under a general category of diseases called proteinopathies.
Diseases that fall under proteinopathies basically cause problems related to clumping of proteins whether inside or outside the brain cells. Considering the tiny spaces inside these brain cells and with no room for expansion, you can just imagine the consequences of these accumulations. It’s vital to note that accumulation of leftover proteins isn’t the sole mechanism responsible for the development of these proteinopathies. Other pathologic processes also come into play.
Neuroscientists are sure of one thing though; you need a properly functioning glymphatic system to remove these leftover proteins. There are other mechanisms that remove leftover proteins, but your glymphatic system covers 50 per cent of the responsibility of eliminating them. Various studies have shown that strokes (both hemorrhagic and ischemic) disrupt the normal functional anatomy of your glymphatic system. It’s also shown in research studies that people who have suffered a stroke exhibit a quick decline in mental functions probably secondary to accumulations of leftover proteins in the absence of a fully functioning glymphatic system.
Lastly, persons who have epilepsy may also benefit from a fully functioning glymphatic system. Researchers have found out that there is a turbulent flow of CSF and ISF (interstitial fluid, the fluid between brain cells) in epileptic brains. This leads to the accumulation of brain proteins that mess with how antiepileptic drugs work making them less efficient. A fully functioning glymphatic system certainly helps in unleashing the full efficacy of these antiepileptic drugs.

Your Glymphatic System may be deep inside your brain, but you can still help it do its job. Below are some of the practical ways:

Take out the protein trash while you sleep. Of course, this isn’t something you consciously do (take out the trash) while you sleep. Multiple studies have documented that CSF flow is maximised inside mice brains during sleep compared to the awake state. This may be the reason why you feel rejuvenated and recharged after a good night’s sleep. Your brain was able to take out its trash while you sleep. Nice.
Ketogenic diets are low-carbohydrate and high-fat diets people often use to lose excess weight. Studies on mice have shown that mice fed with ketogenic diets have better clearance of beta-amyloid and other leftover proteins. The exact mechanisms as to how this happens, remain unclear. So, if you go on a ketogenic diet, you may be assisting your glymphatic system in eliminating these leftover proteins.
Change your posture when you sleep. The same researchers that discovered the glymphatic system are back with a new discovery. They showed that the body posture (or position) of mice while sleeping on their sides (lateral position) significantly increased the flow of CSF and ISF inside the brain, therefore increasing the clearance of leftover proteins. Score one again for these geniuses. We mean the researchers and not the unfortunate mice.
Supplement with MCT oil. MCT stands for medium-chain triglycerides. MCTs increase the number of ketones available for energy utilisation by your brain cells. The more ketones available, the less dependent are your brain cells on your liver to produce ketones from fatty acids.
Exercise regularly to increase blood and glymphatic flow into your brain. Experiments on mice who love running on the wheels inside their cages have shown increased blood and glymphatic flow inside their brains — another clear reason for you to exercise regularly.

So, does the g in glymphatic stand for garbage? It doesn’t. You’ve probably noticed the term supporting brain cells in red colour at the beginning of this article. Supporting brain cells are also called glial cells. That’s where the g comes from. These glial cells or supporting brain cells are the main gatekeepers of CSF in your brain keeping it flowing to ensure proper protein garbage disposal. So now you know that there’s such a thing as a glymphatic system. It has always been there, waiting for someone to discover it. Now be a good glial cell and take out your own garbage.