How does green tea cause alpha brainwaves?

Green tea contains the amino acid L-theanine, which promotes relaxation and may increase alpha brainwave activity. Alpha brainwaves are associated with a state of calm alertness, often experienced during meditation or light relaxation. L-theanine can enhance the production of these brainwaves by influencing neurotransmitter levels, particularly by increasing GABA, dopamine, and serotonin. This effect may lead to improved focus and reduced stress, contributing to a more relaxed mental state.