Theanine and Caffeine Synergy
Tea Improve Concentration

Many people reach for a cup of coffee when they need to concentrate. People with flagging focus might, however, get more bang for their buck with a cup of tea.

A 2007 study conducted by Doctor Foxe found that theanine and caffeine synergise to boost the activity of brain neurons.

Theanine is an uncommon amino acid found almost exclusively in tea. It has been shown to reduce anxiety especially in young women, reduce high blood pressure and enhance concentration and learning.

“People who drank a solution containing about as much theanine as 10 cups of tea were able to focus better on tasks than those who drank a placebo solution,” says Foxe at an international symposium on tea and human health in Washington.

“As little as 100 milligrams of theanine enabled people to focus better on complicated tasks, but only when consumed with 60 milligrams of caffeine — a combination found in roughly 4 cups of green tea,” says Foxe more recently.

"There was a profound synergistic effect," he says. "My take is, we're all self-medicating with this."

John J. Foxe of the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, N.Y., and his colleagues recruited 16 people for tests of attentiveness on 4 days.

Before testing, each individual drank a glass of water. On 3 days, the drink was spiked with 100 milligrams of theanine, 60 mg of caffeine, or both.

The theanine dose was equivalent to that in 4 to 5 cups of tea, and the caffeine translated to about 2.5 cups of tea.

In the difficult tests, participants watched a computer screen and pressed a button when a designated shape appeared on the side of a busy visual field to which an arrow had previously pointed.

Participants' accuracy differed little between days when they got water alone or with only one additive.

Accuracy improved dramatically, however, on the day that they got the theanine and caffeine combination. The attention benefit lasted throughout the 3 hours of testing.

Brain activity, measured throughout each test, showed that theanine induced strong alpha waves in neurons, suggesting restfulness.

But that lasted only until focus was required.

Then, Foxe says, alpha activity dropped precipitously if a person had gotten theanine especially in combination with caffeine indicating that idling neurons had suddenly revved up their activity.

The study was funded by Unilever, which sells Lipton teas.

Foxe, J. 2007. Investigating the role of tea in human cognition: Theanine and caffeine alter the neurophysiology of attention. Fourth International Scientific Symposium on Tea and Human Health. Sept. 18. Washington, DC. http://www.sciencenews.org/articles/20070929/note17.asp

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