In the present study, we examined the cognitive function during mastication of lemon-flavored gum, which is said to enhance cerebral blood flow. Nine healthy subjects (8 female and 1 male) participated in this study. Subjects chewed the gum for 3 min after fasting for 2 h and conducted a Stroop test while continuing to chew. At the end of all answers, gum chewing ended. The response time in the Stroop test was used as an indicator of cognitive function. We set the three conditions (lemon-flavored gum, mint-flavored gum, no gum chewing). There was no significant difference in reaction time between chewing mint-flavored gum and not chewing (p>0.05). However, the response time during chewing gum with a lemon flavor was significant slower than the conditions with mint-flavored gum and without gum chewing (p<0.05, in both). From the results of the present study, it was suggested that the response time delay of the Stroop test observed during the chewing of lemon-flavored gum revealed temporary decay of cognitive function during lemon-flavored gum chewing. It is suggested that lemon-flavored chewing gum forces a brain overload, resulting in a temporary decrease in cognitive function.
Keywords: Stroop test; cognition; gum; mastication.