Matcha contains the nutrients from the entire tea leaf, which results in a greater amount of caffeine and antioxidants than typically found in green tea.
Matcha is rich in catechins, a class of plant compounds in tea that act as natural antioxidants. Antioxidants help stabilise harmful free radicals that can damage cells and cause chronic disease.
Matcha has been shown to improve attention, memory, and reaction time. It also contains caffeine and L-theanine, which can improve several aspects of brain function.
When you add matcha powder to hot water to make tea, the tea contains all the nutrients from the entire leaf. It will tend to have more catechins and antioxidants than simply steeping green tea leaves in water.