In August 2015, Dr. Lee and his team from Stony Brook University in New York found in a study of animals that sleeping in the lateral position is more effective in removing harmful metabolites from the brain and therefore may be effective in reducing the incidence of Alzheimer’s disease, Parkinson’s disease and other neurological disorders, as published in the recent Journal of Neuroscience. Because brain tissue is highly metabolically active, it produces large amounts of metabolites that need to be removed in a timely manner. The glial-lymphatic transport system is the clearing mechanism in the brain that operates at a high level during sleep to cleanse the brain of unwanted metabolites. In the study by Lee et al. the animal model used was the anesthetized rat, which was divided into three groups according to its sleeping position: lateral, supine and prone. Dynamic MRI-enhanced scans were first used to identify the glial-lymphatic pathway through which cerebrospinal fluid travels through the brain parenchyma and interstitial fluid to clear metabolites from the brain. In the group’s study, harmful metabolites in the brain included mainly β-amyloid and tau proteins. To verify the results of the experiment, the study was followed up with fluorescence microscopy and radioactive tracers. From the results of the study, it was found that lateral recumbency was the most effective sleep position for the clearance of brain metabolites by the glial-lymphatic system. In most mammals, lateral recumbency is also the most common sleep position, which is the closest to the natural resting state. In fact, in previous studies on humans, it was found that sleeping in the lateral position is also the most favorable position for the human body compared to other positions, which was also explained in the present study. This researcher believes that the result is mainly related to the anatomical position of the human heart, which is located in the left side of the chest, and the position of the heart is relatively highest when sleeping in the right lateral or supine position, which is conducive to the operation of blood flow. Many types of dementia are associated with sleep disorders, including insomnia, and a growing body of literature suggests that sleep disorders can exacerbate memory loss in Alzheimer’s disease. The results of this study also provide a new perspective on this issue, as the sleep position can affect the body’s ability to clear harmful metabolites from the brain, and the side-lying sleeping position may be able to prevent neurological-related pathologies.