I. Key Factors Involved In The Glymphatic System Health:

II. Natural Ways To Improve Glymphatic System- Glymphatic System Supplements and Diet

III. Other Ways To Improve Glymphatic System- Sleep, Exercise, Meditation, Yoga and More

I was mentioning in my previous article that there are many factors that influence the glymphatic system. The key factors to consider, in my opinion, are:

  • Sleep-awake cycle

  • The health of the brain tissue (particularly astrocytes and neurons) and blood vessels

  • Stress (emotional, chemical, physical stress)

  • Aging process

source: wikimedia commons

1.Sleep-awake cycle

  • There are significant changes in the glymphatic system (especially in CSF flow and volume) when you sleep versus when you are awake. Glymphatic system is significantly stimulated by sleep. Based on research studies (mostly animal studies), there is an increased glymphatic flow by 40-60% during sleep. This could be one of the main reasons why sleep is so restorative- it promotes the removal of neurotoxic waste products accumulated when we are awake (a quick note here: the brain isn’t really sleeping- is still pretty active when we sleep, too as its energy metabolism only declines by 25%) [1]. Dexmedetomidine, an anesthetic drug which induces a stage 2 sleep-like, also increased the glymphatic flow, further supporting the idea that sleep promotes an increased in the glymphatic flow.

  • Sleeping on the left side appears even more beneficial. The glymphatic flow (and the elimination of amyloid beta) is increased when sleeping on the left side or supine (face and torso up), while sitting upright appear to decrease the glymphatic flow [2].

  • What happens when you don’t get sleep ?  PET studies show that amyloid beta accumulates in the healthy brain after a single night of sleep deprivation. One more reason to believe that sleep is important for healthy glymphatic flow. [3].

  • What happens when awake? Research suggests that the glymphatic flow is reduced by 90% when awake [4]. However, the glymphatic flow gets another boost when you exercise [5]. Cardiovascular system (the systolic pulse wave) and respiratory system (breathing rhythm) also influence the CSF flow [6],[7].

 

2.A healthy brain (tissue and blood vessels) are needed to create a healthy environment for the glymphatic system.

*CSF=cerebrospinal fluid

  • In the cranial cavity we have 3 components: the brain occupies most of the cranial cavity volume (80%), followed by blood (10%) and cerebrospinal fluid or CSF (10%). CSF is fluid carried on by the glymphatic system, just like lymph is flowing in the lymphatic system in the body. The brain, blood vessels and CSF are all connected (anatomically and physiologically) and therefore you need healthy brain tissue and healthy blood vessels to improve the glymphatic health.

  • Brain tissue contains neurons and non-neuronal cells called glial cells.

  • Neurons secrete neurotransmitters, and these neurotransmitters help control the glymphatic flow. Just one example: norepinephrine is a key regulator of glymphatic activity and it seems that this neurotransmitter might be responsible for suppression of glymphatic during while awake [8]. Technical: the sympathetic nervous system reduces the CSF secretion, while the cholinergic system increases CSF secretion.  The autonomic nervous system could be responsible for circadian variations of CSF secretion [9]. Check out the BRAIN HEALTH section- I wrote  in details about neurotransmitter deficiencies and how they impact your health.

  • Glial (non-neuron) brain cells. There are a few types of glial cells in the brain: astrocytes, microglia, oligodendrocytes and ependymal cells. Each of these cells have specific functions. Related to the glymphatic system and brain health- astrocytes are very important for the glymphatic health.

  • Astrocytes. The glymphatic system uses a unique system of channels surrounding blood vessels (called perivascular channels) formed by astrocytes. Healthy astrocytes are needed to create and maintain these channels. Astrocytes are also heavily involved in the transport of fats [10], and the maintenance of healthy blood brain barrier (BBB). Astrocytes provide support for brain cells, working together with neurons and myelin producing cells (oligodendrocytes). They play an essential role in neuroplasticity, the use and clearance of the synapses/ neurotransmitters and create a healthy, anti-inflammatory environment in the brain tissues (astrocytes create BDNF, while decrease TGF-β, IL-10 and other proinflammatory molecules). Astrocytes can modify gene expression related to brain plasticity, participate in the production of neurosteroids (allopregnanolone, estrogen, and DHEA) and promote myelin repair. Astrocytes also make the glial scars in an attempt to limit damage and inflammation of the brain [11]. Aquaporin-4 (AQP4) is a special protein that helps conduct water through the cell membrane. In the brain, AQP4 is primarily expressed in astrocytes [12].

  • When good cells turn bad. Healthy astrocytes help maintain a healthy brain. However, astrocytes can become harmful. Neurodegeneration and acute brain injuries generate an abnormal increase in the number of astrocytes, also known as reactive astrocytes. Reactive astrocytes called A1 cells not only lose some beneficial functions (ie synapse clearance, neuroplasticity) but they become very toxic to the neurons, causing neuron death. It appears that the reactive astrocytes (rather than microglial cells, as previously thought) are the key drivers of neuron death. Furthermore, these reactive astrocytes are also toxic to the myelin producing cells (oligodendrocytes) [13]. AQP4 is also considered a key player in neuroinflammation in the context of autoimmunity [14].

  • The brain’s blood vessels. The blood vessels of the brain also have a significant impact on the brain tissue (they provide oxygen and nutrients) but also on the glymphatic system. Anatomically, the glymphatic vessels are surrounding the blood vessels. Glymphatic activity, at least in part, is driven by the pulsation of the arteries [15].

3. Stress. Any form of stress will have a negative impact on the glymphatic system.

  • There are several mechanisms involved, and the field of psyhoneuroimmunology is trying to connect the dots and how stress/ emotions influence the nervous system and the immune system.

  • Physical stress, chemical stress (ie environmental toxins, infections, meds) and emotional stress will also affect the glymphatic system, by affecting neurons, blood vessels and non-neuronal cells [16],[17],[18],[19],[20].

  • Research shows that astrocytes react quickly to emotional stress (both chronic and acute stress) [21],oxidative and chemical stress, inflammation, brain tissue damage and infections.

Did you know ? Positive emotions/mindset had been considered very important in ancient forms of medicine. In Ayurveda medicine, stuck, negative traumas are the major culprits for impairing the lymph flow in the brain. Scientific studies found a correlation between stress exposure (in significant relationship with family, partner) and involvement of the lymph nodes in cancer (basically the cancer more likely to spread to these lymph nodes if the person would be under stress) [22]  

4.The aging process. Research shows that aging is associated with a decrease in CSF flow and CSF pressure [23],[24],[25],  while CSF volume appears to increases with age [26], according to some studies).

 

II. How To Improve Glymphatic Flow -Glymphatic System Supplements & Diet

  • Ginkgo Biloba. Ginkgo biloba improves cerebral blood flow [27], and decrease stress levels [28]. May even protect astrocytes from chemical stress [29], improve sleep, has anti aging /antioxidant qualities [30] and is a well-known supplement for neurodegenerative conditions like Alzheimer’s and MS.

  • Adaptogens. Adaptogen herbs like ashwagandha, bacopa, gotu kola, rhodiola and maca can also be beneficial. They optimize brain function (including neurotransmitter balance), the ability to cope with stress, improve sleep and have anti-aging benefits, too.

  • Omega 3 fatty acids seemed to be particularly helpful to improve brain lymphatics [31] .DHA is better than EPA for brain health, and high DHA doses are found in prenatal formulas.

  • Vitamins and Minerals. All vitamins and minerals are important for brain health, but B1, folate, B6, B12, E, C and D, magnesium, zinc and selenium would be the top supplements to consider.

  • Aminoacids. Among amino acids, NAC is well-known as a detox agent, therefore supporting the lymphatic system (which also has detox effects). ALCAR, taurine, tryptophan, tyrosine and GABA support healthy neurotransmitter levels and overall a healthy brain.

 

  • Diet. A low carb diet, either paleo or keto style could help improve glymphatic flow. Fasting can be helpful too, as it promotes a deep detox as a cellular level (autophagy). The following foods (paleo/keto friendly) also have anti inflammatory /antioxidant compounds: green leafy veggies, cruciferous family (cabbage, broccoli, etc), fatty fish, nuts, seeds, berries and healthy oils (olive, coconut). I would add a lot of herbs and spices to the diet (think Indian dishes) to further improve sugar metabolism and digestion.It works both ways- the glymphatic system regulates the glucose metabolism and insulin resistance in the brain, while altered sugar metabolism (as seen in diabetes) contributes to impairment of the glymphatic activity (and decline in cognitive function) [32].

Since the glymphatic system is connected with the general lymphatic system, it is worth looking into natural ways to improve lymphatic drainage in the body. More details here and here. 

III. Other Natural Ways To Improve Glymphatic Drainage: Sleep, Exercise, Meditation, Massage, Yoga and More

  • Sleep well at night, stay active during the day. Regarding sleep- the theta brain waves promote efficient drainage of the glymphatics [33].  Besides physical exercise, it is worth adding some brain exercise (training). I like brain HQ as it had been shown to improve neuroplasticity, was designed by top neuroscientists, and there is a lot of research behind these brain exercises. 

  • Massage (including lymphatic drainage techniques), osteopathy, craniosacral therapy and chiropractic adjustments could help as the CSF seem to be prone to stagnation within the spinal canal [34]. If you don’t go to massage therapy, you can try self massages like this one or the Ayurvedic Abhyanga. 

  • Glymphatic system meditation link. Mindfulness meditation and yoga. Could meditation improve glymphatic flow? Mindfulness meditation (MM) has the potential to improve the glymphatic system in a few different ways. There is a significant amount of scientific evidence suggesting that MM can improve stress and sleep [35], [36] (also promoting the beneficial theta brain waves) [37]. Meditation improves cerebral blood flow in some areas of the brain [38], and has strong anti aging qualities [39], [40]- which are key factors that promote a healthy glymphatic system.

  • Yoga shares similar health benefits with meditation. They both improve posture, which would help relief the stagnation of the CSF in the spinal cord [41]. 

  • Brain training programs like Holosync mimic the benefits of both meditation and deep sleep.

  • Decongesting nose airways and sinuses with Neti pot (using salted water) and nasya (inhalation of herbalized oils into the nose and sinuses) could help improve the glymphatic flow, because the nasal lymphatics and the CSF are connected [42].  Just make sure you learn the right techniques and use sterile utensils.