A Pilot Study of Near-Infrared Light Treatment for Alzheimer's Disease

Background: Laboratory investigations have demonstrated that near-infrared (NIR) light treatment can reduce amyloid-beta burden in models of Alzheimer's disease (AD). However, previous clinical studies are rather insufficient. Objective: Before starting a large-scale clinical trial, we performed a pilot study to characterize the efficacy of NIR light for AD patients. Methods: Twenty participants with mild to moderate AD were assigned randomly to the intervention (1060-1080 nm and 800-820 nm NIR light treatment for 12 weeks) or control group (without sham treatment). Safety and efficacy were evaluated at baseline, week 4, 8, and 12, and 4 weeks after treatment. Results: In the intervention and control groups at week 12, mean changes from baseline on the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog) were -3.1 and -1.3 (p = 0.5689). Mean changes from baseline on the Activities of Daily Living (ADL) were -3.6 versus 3.1 (p = 0.0437). Mean changes from baseline on the Mini-Mental State Examination (MMSE) were 4.4 versus 1.0 (p = 0.0253). The percentage of participants who exhibited a change larger than 4 points from baseline to week 12 was determined for the intervention and control groups on the ADAS-Cog (57% versus 29%), ADL (29% versus 0%), and MMSE (57% versus 14%). Treatment with NIR light did not increase the incidence of adverse events in participants. Conclusion: NIR light treatment appears to be safe and potentially beneficial for AD patients. It improved cognitive function and activities of daily living. The preliminary data encouraged us to launch a large-sample, multicenter, double-blind clinical trial.