From the Tea and Health Symposium from September 2007: Dr. John
Foxe, Ph.D., Professor of Neuroscience, Biology and Psychology
at City College of the City University of New York, has been
conducting human studies to measure the effect of theanine, an
amino acid present in all kinds of tea (not herbal), on the
brain and attention. Theanine can cross the blood-brain barrier
and has been shown to reduce mental and physical stress. Dr.
Foxe monitored brain activity in subjects after drinking either
250 mg of theanine or a placebo. The subjects then worked on
various 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,” he said. His research also suggests that theanine
in combination with caffeine may be more effective than either
one alone in improving attention. Blood concentrations of
theanine increase and the brain’s alpha wa