Effects of coffee drinking on reduction of mental stress in young women

Abstract

Coffee is among the most common luxury beverages for Japanese consumers. We investigated the relationships between ingestion of coffee and reduction of mental stress in 256 young Japanese women. We administered a questionnaire to the subjects about preference for coffee and associated feelings of relaxation. An organoleptic test also was performed. Finnaly, effects of coffee were investigated after subjects were palced under mental stress (New Stroop test for 4 min, followed by Uchida-Kraepelin test for 20 min). The degree of mental stress was evaluated by chromogranin A, which is secreted with catecholamines in saliva. <BR> Among the 68% of subjects whose questionnaire responses indicated that they liked coffee, 68% felt relaxed when they drank it. In an organoleptic test, coffee extracted at 80°C exhibited greater relaxation effect than coffee extracted at 65 or 95°C. This effect showed a significant negative relationship to sourness, suggesting that relative lack of sourness enhances the relaxed feeling. Coffee drinking also decreased experimentally induced mental stress evaluated by salivary chromogranin A concentration. [J Physiol Sci. 2006;56 Suppl:S206]