An object is to find out a safe component that can effectively exhibit action including the protection of a brain function, the prevention or alleviation of a reduction in cognitive ability, and the prevention or alleviation of dementia. A component of a plant body of a hybrid between Camellia sinensis and Camellia taliensis is contained as an active component. The hybrid between Camellia sinensis and Camellia taliensis is preferably Sunrouge. A tea leaf extract of the plant body of the hybrid between Camellia sinensis and Camellia taliensis is preferably contained.
