The glymphatic system is an often-overlooked but essential part of brain health. Often referred to as your brain's natural waste clearance system, it plays a critical role in removing toxins and metabolic waste while you sleep. Understanding how this system works can help explain why quality sleep is so important for memory, focus, cognitive function, and long-term brain health.

What is the Glymphatic System?

The glymphatic system’s main role is to clear waste from your brain while you sleep. As our brains are among the most complex organs in the body, they have numerous requirements to support, regulate, and communicate with our bodies for daily functioning. The brain’s responsibility in cell signaling and communication requires an enormous amount of energy; in fact, the brain alone uses about 20% of energy intake from the nutrients we consume.

After our brains use up fuel, waste remains as a byproduct. The glymphatic system comes to the rescue, preventing waste products such as lactic acid, specific proteins, and potassium from building up. Think of the glymphatic system as a shower for the brain: it uses fluid called cerebrospinal fluid (CSF) and interstitial fluid (ISF), to remove excess waste and bring our brains back to balance.

The intricate and vital role the glymphatic system plays in our brain, body, and overall signaling would not be possible without high-quality sleep, as it is most active during our most restorative stage of sleep.

Glymphatic System and Sleep

There are two basic phases of sleep: Non-REM (rapid eye movement) sleep and REM sleep.

Non-REM can be broken into 3 different stages:

Stage 1 is the in-between phase where you’re not fully awake, but you’re not entirely sleeping. Your heart rate typically slows, and your muscles relax.

Stage 2 involves being in a light sleep where brain waves begin to slow down and body temperature drops.

Stage 3 is where the most restorative sleep happens. Heart rate and breathing slow to their lowest levels, your body increases blood supply to your muscles for repair, hormones are released, and energy levels become restored.

The glymphatic system is known to work best during stage 3 of non-REM sleep. During this stage, the neurotransmitter norepinephrine (associated with “fight-or-flight” response) is low, allowing for the most restorative stage of sleep.

REM

After about 90 minutes of being asleep, we enter REM sleep. In REM, the brain and body are energized, breathing becomes faster, eyes dart back and forth, and limbs become immobile. In this stage, the regions in the brain associated with memory, learning, and mood stability are stimulated.

Check out my previous blog, “How Much Sleep Do You Actually Need?” to read more about sleep stages, circadian rhythm, and sleep hygiene.

Ways to Improve Your Glymphatic System

Maintain a consistent bedtime and a similar wake-up time every day.
- Our circadian rhythm, or sleep-wake cycle, is foundational to overall health, including mood regulation, appetite, and even proper restoration through good quality sleep.
Focus on your bedtime routine.
- Limiting blue light exposure from our phones, computers, tablets, and TVs before bed helps support our body’s natural melatonin production, a hormone that supports sleep. My other go-to practices to support my sleep:
  - Evening strolls, drinking herbal tea, avoiding meals 2 hours before bedtime, and taking supplements such as magnesium glycinate and l-theanine.
- Read more about my sleep hygiene and more ways to optimize yours by reading my previous blog, “Ways to Optimize Your Sleep Hygiene.”
Manage stress
- High levels of stress can impair sleep by affecting how quickly you fall asleep and your ability to stay asleep.

If you want to focus on your body’s natural ways it supports itself, start with your sleep! Our bodies are resilient and smart; we just need to give them the tools to thrive.