The "waste disposal system of the brain" is an apt description of the glymphatic system – a vital cleaning mechanism that becomes active during sleep. This system plays a crucial role in brain health by removing waste products such as beta-amyloid and tau proteins, which are associated with neurodegenerative diseases like Alzheimer’s.

Function of the Glymphatic System

During sleep, the spaces between brain cells expand, facilitating the removal of waste products. Sleep position plays a key role in this process: studies show that sleeping on one’s side – particularly the left side – optimizes this cleaning process. Conversely, sleeping on one’s back can increase pressure on certain brain areas, reducing the effectiveness of the glymphatic system.

Importance of Sleep Quality

In addition to sleep position, the duration and quality of sleep are critical. Even one sleepless night can raise tau protein levels in the brain by up to 50%. Chronic sleep deprivation is associated with an increase in amyloid-β plaques and a higher release of synuclein, which is linked to Parkinson’s disease. These findings highlight the importance of adequate and restorative sleep for long-term brain health.

Conclusion

The left side sleeping position is considered the most effective for supporting the glymphatic system. Researchers discovered this by placing anesthetized rats in three different positions – on their backs, upright, and on their sides – inside a brain scanner. Using magnetic resonance imaging (MRI) and contrast agents, they tracked how well cerebrospinal fluid flowed through the brain and washed out waste products.