CALM2 and Cognitive impairment: As the upregulation of calcium calmodulin-dependent protein kinase (CaMII) is effective for preventing memory decline and for the upregulation of synaptic plasticity-related protein in the hippocampus [20], it was considered that the upregulation of these proteins by matcha and decaffeinated matcha could play an essential role in preventing memory decline, aging and cognitive impairment.