Singapore, July 21, 2008: Drinking four to five cups of tea a day may help maintain a healthy mind and body, according to new research published in a supplement to the August issue of the Journal of Nutrition. One study's results suggest that four to five cups of tea a day may improve attention and focus. This and other studies on tea polyphenols, including research on neurological health, genetic susceptibility to cancer, and insulin sensitivity are included in the Proceedings of the Fourth International Scientific Symposium on Tea and Human Health. The supplement also provides an update on the evidence in support of tea's role in cardiovascular health, and the bioavailability of its beneficial flavonoids.

 

"This supplement highlights many of the new frontiers being investigated regarding black and green tea's potential public health benefits," said Tea Symposium co-chair, Prof Jeffrey Blumberg, Friedman School of Nutrition Science and Policy and Director, Antioxidants Research Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston.

 

Dr Lenore Arab, Professor of Internal Medicine at the University of California, Los Angeles and Blumberg's partner as Tea Symposium co-chair adds that, "There are tremendous advancements to better understand the mechanisms by which tea may reduce risk for heart disease, certain cancers, type II diabetes, and help maintain neurological function."

 

The results of a new human, placebo-controlled, trial published in the Proceedings of the Fourth International Scientific Symposium on Tea and Human Health found that theanine, an amino acid present almost exclusively in the tea plant, including black, green, and oolong varieties, actively alters the attention networks of the brain. "Our results show that after having theanine, individuals had significant improvements in tests for attention, and that activity in cortical regions responsible for attention functions was enhanced," said author Dr John Foxe, Professor of Neuroscience, Biology and Psychology at City College of the City University of New York. "What's more, we have seen that just 20 minutes after consuming theanine, the blood concentrations increase and the brain's alpha waves are impacted. It lasts about three to four hours, which we have speculated may be why people tend to drink a cup of tea every three-to-four hours during the day," added Dr Foxe.

 

The new research from Dr Foxe and his team used electrophysiological measures to monitor brain activity after individuals drank solutions containing a placebo, 50 mg caffeine, an amount of theanine equivalent to five to six cups of tea, or a combined treatment. The subjects were asked to complete a variety of attention-related computerized tasks.

 

The results from Dr. Foxe's laboratory, the Cognitive Neurophysiology Laboratory at the Nathan S. Kline Institute for Psychiatric Research in Orangeburg, New York, supported by the Lipton Institute of Tea, suggest that the effects of theanine in combination with caffeine are even greater than with either one alone in improving attention. Theanine may work synergistically with caffeine to help induce a more calming, relaxed state, but one that allows the mind to focus and concentrate better at tasks Theanine 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. A cup of brewed tea typically contains between 10 and 20 mg of theanine.