Therapeutic effects of 40 Hz light stimulation on clinical and pathological features of Alzheimer’s disease

BACKGROUND: Current pharmacological treatments offer only limited benefits in altering the course of Alzheimer's disease (AD). Given these limitations, nonpharmacological interventions have emerged as potential therapeutic strategies. This study investigates the therapeutic effects of 40 Hz light stimulation in AD and analyzes blood biomarkers to explore its potential disease-modifying effects. METHODS: This longitudinal study examined the effects of 40 Hz light stimulation on clinical symptoms and blood biomarkers in AD patients. Fourteen individuals were enrolled, with 11 completing the 3-month light stimulation, and 6 continuing to 6 months for the final blood biomarker analysis, including amyloid beta (Aβ) oligomers, Aβ-40, Aβ-42, tau phosphorylated at threonine 181 (p-tau181) and 217 (p-tau217), and neurofilament light chain. RESULTS: = .014). At 6 months, cognitive function and neuropsychiatric symptoms remained stable or improved in 33.3% and 66.7% of participants, respectively. Biomarker analysis showed decreased Aβ oligomers, increased Aβ-42 and reduced p-tau, suggesting potential disease-modifying effects. CONCLUSIONS: 40 Hz light stimulation demonstrated short-term benefits in cognitive stability, caregiver burden relief, and sleep improvement, with biomarker findings indicating possible neuroprotective effects.