Your brain doesn’t have a traditional waste removal system like the rest of your body, but it still needs to clear out toxins. Scientists have discovered a special process, called the glymphatic system, which acts like a cleaning service for your brain—and it works best when you are in deep sleep.

The glymphatic system allows cerebrospinal fluid (CSF) to flow into the brain through spaces around blood vessels, washing away waste.[1] The fluid then drains out, carrying toxins away. This system depends on a water channel called Aquaporin-4 (AQP4), found in brain cells called astrocytes. When AQP4 doesn’t function properly, waste accumulates, increasing the risk of neurodegenerative diseases like Alzheimer’s Disease and Parkinson’s Disease.[1]

When we age however, the brain’s process to clear waste becomes less effective.[2] The glymphatic system slows down while sleep becomes more disrupted, and the brain accumulates harmful proteins such as amyloid-beta and tau, both linked to Alzheimer’s Disease.[3] This buildup of waste metabolites contributes to a person’s sleep disturbances, memory issues, and increases their risk of brain diseases. Worse, the combination of a weakened brain lymphatic system and chronic inflammation can block waste removal, creating a vicious cycle where poor sleep leads to the accumulation of more toxins, and in turn, more toxins worsen sleep.[2]

Prioritizing deep non-REM sleep is one of the best things you can do for long-term brain health.

5 Key Takeaways: 

• Your brain has a built-in cleaning system (known as the glymphatic system) that removes waste while you sleep.

• Deep sleep is essential for brain detoxification—without it, harmful proteins like amyloid-beta and tau can build up.

• As you age, your brain’s waste removal slows down, increasing the risk of neurodegenerative diseases like Alzheimer’s Disease and Parkinson’s Disease.

• Chronic inflammation combined with a weakened glymphatic system make waste clearance even harder as you get older.

• Prioritizing quality sleep and deep rest is key to keeping your brain healthy and reducing disease risk.