Influence of Continuous Ingestion of Matcha Latte on Stress: A Preliminary Study

Abstract

Matcha has high contents of theanine, caffeine, and epigallocatechin gallate (EGCG). Among these, theanine reduces psychological and physiological stress responses, although this effect is disturbed by caffeine and EGCG. It was reported that the continuous ingestion of high-quality matcha, whose molar ratio of caffeine + EGCG combined to theanine + arginine combined was maintained at less than two, reduces stress responses¹⁾. However, most matcha on the market has an unfavorable ratio. In a previous study, we investigated the influence of the continuous ingestion of matcha with a ratio of over two, on emotional behaviors after stress in mice. Continuous ingestion of the matcha may prevent loss of motivation after stress²⁾. Therefore, we investigated the influence of the continuous ingestion of matcha products, matcha latte, on the change of motivation after stress in humans. Because activation of the sympathetic nervous system is associated with motivation change, the salivary α-amylase activity was monitored as an index of sympathetic nervous activity. Continuous ingestion of the matcha latte prevented impairment of the response of α-amylase activity to stress, and this may be due to the synergistic effects of caffeine and other matcha components. Taken together, continuous ingestion of matcha may contribute to the maintenance of motivation.