Effects of Oral Intake of Noncentrifugal Cane Brown Sugar, Kokuto, on Mental Stress in Humans

Abstract

　We investigated the inhibitory actions of oral noncentrifugal cane brown sugar (Kokuto) on mental stress in healthy subjects. When the subjects orally consumed 5 g of Kokuto before a 15-min Uchida-Kraepelin psychodiagnostic test (pre-task group), the salivary levels of stress biomarkers, including chromogranin A, α-amylase, secretory immunoglobulin A, dehydroepiandrosterone, and testosterone, were lower at 5 min after the test compared with those in the control group. However, Kokuto intake after the stress task (post-task group) showed little inhibitory effects. Subjective ratings for mental state using the visual analog scale were significantly lower in the pre-task group than in the control group, while the post-task group showed no significant differences. Moreover, Profile of Mood States scores showed a positive influence on the five negative mood states, which consequently improved vigor, in the pre-task group. These results suggest that oral intake of 5 g of Kokuto may efficiently suppress mental stress.