Effect of Matcha green tea on cognitive functions and sleep quality in elderly adults with cognitive decline: a randomized controlled study over 12 months

Nutrition is a pivotal factor in the prevention of dementia. Matcha green tea powder, which contains L‐theanine, caffeine, and epigallocatechin gallate, has the beneficial effects of each constituent on cognitive functions and mood. However, no long‐term clinical study has yet been performed to evaluate the effect of Matcha on psychological functions. Here, we performed a randomized, double‐blinded, placebo‐controlled, clinical study, conducted over 12 months, to investigate the effect of Matcha on cognitive functions and sleep quality. Furthermore, the relationship between blood and neuroimaging biomarkers and the effect of Matcha was investigated.