Dr. Hoang Tien Trong Nghia, head of the Neurology Department at Military Hospital 175, highlights age-specific sleep recommendations from leading health organizations, including the National Sleep Foundation and the American Academy of Sleep Medicine (AASM).
For adults aged 18-64, 7-9 hours of sleep each night is recommended. This need slightly decreases for those over 65, who generally require 7-8 hours. Children, whose brains are actively developing, need more sleep: infants typically need 14-17 hours, and adolescents 8-10 hours.
Dr. Nghia explains that the brain requires 7-9 hours of rest to perform critical tasks impossible during wakefulness. A key function is clearing metabolic waste via the Glymphatic system. During deep sleep, the spaces between brain cells widen, enabling cerebrospinal fluid to flush out harmful proteins like Beta-amyloid and Tau, which accumulate throughout the day and are strongly linked to Alzheimer's disease.
Sleep is also essential for memory consolidation and learning. It filters information, moving short-term memories from the hippocampus to the cerebral cortex for long-term storage. Additionally, sleep eliminates redundant information, particularly during REM and slow-wave sleep stages.
This restorative process extends to synaptic homeostasis and emotional recovery. While awake, the brain constantly forms new neural connections, which consumes significant energy. Sleep "prunes" weaker connections, restoring the neural network to a balanced state, ready for new information. Furthermore, sleep regulates the connection between the amygdala, the brain's emotional control center, and the prefrontal cortex, responsible for logical thought. This regulation helps individuals maintain composure and make accurate judgments the following day.
Beyond duration, the quality of sleep, or "sleep architecture," is equally vital. The brain needs not only sufficient time but also to complete 4 to 5 sleep cycles each night. Each cycle, lasting 90-110 minutes, comprises all stages: light sleep, deep sleep, and REM sleep.
Consistently interrupted sleep, such as from sleep apnea, even if totaling 8 hours, can lead to a severe deep sleep deficit. The impact of such interruptions can be more detrimental than getting only 6 hours of uninterrupted sleep. To maintain an adult brain's clarity, sharpness, and to prevent neurodegenerative diseases in later life, securing 7-8 hours of continuous sleep each night is essential.
Le Phuong
