Participants took 300 mg of EGCG or a placebo. Before and two hours afterwards, researchers took a resting-state electroencephalogram (EEG) to measure brain activity.
While the placebo group did not change, the EGCG group had a greater sense of calm, reduced feelings of stress, and a significant increase in alpha, beta, and theta brain waves, which correspond, respectively, to relaxation, reasoning and creative powers.