Tea Theanine Link to Attention and Focus The results of several ongoing human trials presented by John Foxe, Ph.D., Professor of Neuroscience, Biology and Psychology at City College of the City University of New York, have found that theanine from tea actively alters the attention networks of the brain. Theanine is an amino acid present almost exclusively in the tea plant. After drinking tea, the amino acid theanine, which is present in Green, Black and Oolong varieties, is known to be absorbed by the small intestine and cross the blood-brain barrier where it affects the brain's neurotransmitters, and increases alpha brain-wave activity. This alpha brain rhythm is known to induce a calmer, yet more alert, state of mind.
Foxe and his team used electrophysiological measures to monitor brain activity after individuals drank solutions containing either 250mg theanine or placebo. The subjects were asked to complete a variety of attention-related computerized tasks. "Our results showed that after having theanine, individuals showed significant improvements in tests for attention and that activity in cortical regions responsible for attention functions was enhanced," said Dr. Foxe.