Sleeping on your side, particularly the left side, is the optimal sleep position to improve overall health, notably for clearing cerebral waste and managing acid reflux.

noli's read

Research does indeed support that lateral decubitus (side sleeping) is preferable for the airways, reducing the risks of sleep apnea compared to the supine position. Regarding the clearing of cerebral waste (the glymphatic system), studies on animal models, notably published in 'The Journal of Neuroscience', suggest that this position could optimize the elimination of toxins, although evidence in humans remains more limited and requires further research. The advantage of the left side for acid reflux is recognized by observational and clinical studies, as this position keeps the esophagogastric junction above the level of gastric acid. However, labeling this position as a universal 'optimal solution' is a simplification. For most healthy individuals, the body naturally changes position during the night, and there is no strong evidence suggesting that a fixed position is imperative for long-term health in people without specific medical conditions.

the sources

No named source held this one up — that absence is part of the verdict.