Effect of Single Administration of Mulberry Milk on the Cognitive Function of 6–12-Year-Old Children: Results from a Randomized, Placebo-Controlled, Crossover Study

Abstract

Currently, cognitive enhancers are considered necessary because they play a critical role in daily and social behaviors. The cognitive-enhancing effect of mulberry milk has gained attention due to the cognitive-enhancing effect of this anthocyanin-rich substance and the cognitive-enhancing effect of mulberry fruit in animal models. However, the effect of anthocyanin-rich mulberry milk in clinical trials especially in children is still unknown. This study was a randomized double-blind crossover intervention. A total of forty-six healthy, normal, cognitive subjects aged 6–12 years old were provided mulberry milk (containing mulberry 10 g) or placebo milk (50 mL). Attention and cognitive function were assessed using the auditory odd ball paradigm of event-related potential, whereas working memory was assessed using a computerized battery test. The assessment was performed at baseline and then at 1.5 and 3 hours postdosing. At the end of study period, the activities of acetylcholinesterase (AChE) and monoamine oxidase (MAO) together with that of saliva cortisol were determined. Following mulberry milk intervention, the decreased N100 latency and the increased P300 amplitude were increased both at 1.5 and 3 hours after dosing. The decreased response time of digit updating was observed both at 1.5 and 3 hours after dosing, whereas the decreased response time of picture updating was observed at 3 hours after dosing. In addition, the reduction of saliva cortisol was also observed at both periods. The improvement of attention and cognitive processing capabilities together with the working memory suggests the cognitive-enhancing potential of mulberry milk for school-age children. The possible underlying mechanism may be associated partly with the reduction of cortisol, a stress hormone.