Fjell Anders M, Walhovd Kristine B
Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway.
Computational Radiology and Artificial Intelligence, Department of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
Neuroscientist. 2025 Oct;31(5):483-498. doi: 10.1177/10738584241309850. Epub 2025 Jan 30.
It is a widely held opinion that sleep is important for human brain health. Here we examine the evidence for this view, focusing on normal variations in sleep patterns. We discuss the functions of sleep and highlight the paradoxical implications of theories seeing sleep as an adaptive capacity versus the theory that sleep benefits clearance of metabolic waste from the brain. We also evaluate the proposition that sleep plays an active role in consolidation of memories. Finally, we review research on possible effects of chronic sleep deprivation on brain health. We find that the evidence for a causal role of sleep in human brain health is surprisingly weak relative to the amount of attention to sleep in science and society. While there are well-established associations between sleep parameters and aspects of brain health, results are generally not consistent across studies and measures, and it is not clear to what extent alterations in sleep patterns represent symptoms or causes. Especially, the proposition that long sleep (>8 hours) in general is beneficial for long-term brain health in humans seems to lack empirical support. We suggest directions for future research to establish a solid foundation of knowledge about a role of sleep in brain health based on longitudinal studies with frequent sampling, attention to individual differences, and more ecologically valid intervention studies.
人们普遍认为睡眠对人类大脑健康很重要。在此，我们审视这一观点的证据，重点关注睡眠模式的正常变化。我们讨论睡眠的功能，并强调将睡眠视为一种适应能力的理论与认为睡眠有助于清除大脑代谢废物的理论所具有的矛盾含义。我们还评估了睡眠在记忆巩固中发挥积极作用这一观点。最后，我们回顾了关于长期睡眠剥夺对大脑健康可能影响的研究。我们发现，相对于科学和社会对睡眠的关注程度而言，睡眠在人类大脑健康中起因果作用的证据出奇地薄弱。虽然睡眠参数与大脑健康各方面之间存在已确立的关联，但研究和测量结果在总体上并不一致，而且睡眠模式的改变在多大程度上代表症状或原因尚不清楚。特别是，一般认为长时间睡眠（>8小时）对人类长期大脑健康有益这一观点似乎缺乏实证支持。我们建议未来研究的方向，即基于频繁抽样的纵向研究、关注个体差异以及更具生态效度的干预研究，为确立睡眠在大脑健康中的作用的坚实知识基础。
