Auraptene in the Peels of Citrus Kawachiensis (Kawachibankan) Contributes to the Preservation of Cognitive Function: A Randomized, Placebo-Controlled, Double-Blind Study in Healthy Volunteers

Objectives Dementia, which is characterized by a progressive decline in cognitive function, is a major concern in aging societies. Although a number of treatments have been approved, an effective therapy to prevent the disorder is lacking. A supplement that improves cognitive function would benefit patients. The aim of this study was to assess whether auraptene, a citrus coumarin, has a protective effect on cognitive decline. Design A randomized, placebo-controlled, double-blind study Setting Outpatient medical check-up program for cognitive disorders Participants 84 adult volunteers (they are cognitively normal) met inclusion and exclusion criteria to participate. Intervention 42 participants received auraptene enriched (containing 6.0 mg/day of auraptene) test juice, and another participants received placebo juice. Measurements 1) Mild Cognitive Impairment (MCI) Screen using the 10-word immediate recall test. 2) The Mini-Mental State Examination (MMSE). Cognitive assessment ware carried out baseline and at 24 weeks. Results Auraptene enriched test juice did not improve cognitive function after 24 weeks compared with baseline data. However, there was a significant difference in the percentage change in cognitive function between the test and placebo orange juice groups (6.3 ± 18.9 vs. −2.4 ± 14.8, P < 0.05). Multiple regression analysis demonstrated a significant independent relationship between the percentage change in the 10-word immediate recall test score and test juice consumption including baseline 10-word immediate recall test score in all subjects. Conclusion This is the first study to assess the effectiveness of auraptene in the prevention of cognitive decline. Our results suggest that auraptene is a safe supplement for the prevention of cognitive decline.