Abstract: Alzheimer’s disease (AD), a major neurodegenerative disorder, involves multiple pathological processes including amyloid-β (Aβ) deposition, tau protein hyperphosphorylation, and neuroinflammation. Although current pharmacotherapies have made some progress, they remain limited by inadequate efficacy, significant side effects, and high costs, which hinder their utility in long-term clinical management. In recent years, physical intervention strategies, particularly non-invasive neuromodulation approaches, have gained increasing research interest. Among these, 40 Hz gamma-frequency light stimulation has attracted considerable attention due to its ability to specifically modulate neural oscillations and its demonstrated potential to mitigate AD pathology and cognitive impairment. Emerging evidence indicates that this therapy may restore glymphatic system function, thereby enhancing metabolic waste clearance in the brain and slowing disease progression. This review systematically summarizes recent advances in 40 Hz light therapy for AD via glymphatic system modulation, examining its mechanisms, animal study findings, current translational status, and future directions, with the aim of laying a theoretical foundation for further research and clinical application in this field.
Key words: 40 Hz light therapy; non-invasive treatment; Alzheimer’s disease; glymphatic system; aquaporin 4
（Acta Laser Biology Sinica, 2026, 35(2): 121-129）