Findings Published in August Issue of Journal of Nutrition NEW YORK, July 18
NEW YORK, July 18 /PRNewswire/ -- 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, Jeffrey Blumberg, Ph.D., Professor, 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. Lenore Arab, Ph.D., 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."
Theanine in Tea Increases Attention and Focus
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 John Foxe, Ph.D., 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.
Tea May Protect Aging Brains from Alzheimer's and Parkinson's Diseases
Newly published study by Sylvia Mandel, Ph.D., of the Eve Topf Center for
Neurodegenerative Diseases in Israel, show that the active flavonoids in tea
may have multiple mechanisms of action on a cellular level on maintaining
neurological health. Mandel, who has been studying the effects of tea on
brain functions in laboratory and animal models for over a decade, looked at
animal models of neurological diseases such as Parkinson's and Alzheimer's.
An amount of purified EGCG equal to about two to four cups of green tea per
day was provided to animals with induced Parkinsonism as part of their diet to
evaluate how their symptoms improved or progressed. They found that when the
animals are fed green tea EGCG, the polyphenol appeared to prevent brain cells
from dying, and showed improvements in reducing compounds that lead to lesions
in the brains of animals with Alzheimer's disease.
"In the past, it was thought that once brain cells were damaged, there was
no way to repair them. Not only may the EGCG help prevent brain cells from
dying, it appears that the polyphenol may even rescue the neurons, once they
have been damaged, to help them repair," says Dr. Mandel.
While numerous studies have concluded that diets rich in fruits and
vegetables support the body in fighting neurological decline through
antioxidant mechanisms associated with their high flavonoid content, the
importance of tea's polyphenolic flavonoids in supporting healthy brain cells
appears to go beyond the simple oxygen species scavenging, involving
pleiotropic effects on numerous biological pathways to help keep human brain
cells from dying and even help repair them when they are subjected to insults
that damage the cells' DNA.
Human epidemiological and new animal data from around the world suggests
that drinking tea -- especially those rich in flavonoids named catechins --
may help support the brain as we age. Recent publications from earlier this
year also contribute to the growing body of research on the potential
neuroprotective benefits of tea polyphenols. Tan et al found an inverse
association between black tea and Parkinson's disease, based on a 12 year
prospective study of over 63,000 men and women, that was due to black tea
ingredients separate from its caffeine content. A retrospective study, by
Kandinov et al, of nearly 300 patients with Parkinson's disease found that
drinking three or more cups of tea per day delayed motor symptoms by 7.7
years. In addition to epidemiological data, results from recent animal
studies showed that tea polyphenols may improve memory in Alzheimer's disease
(Rezai-Zadeh et al), and be neuroprotective against oxidative stress (Hague et
al).
Tea May Alter Cancer Genetics
Results from a tea intervention on the role of green tea on the prevention
of cancer provided insights into the cutting-edge field of nutri-genomics, or
how gene susceptibility toward chronic diseases can be altered through dietary
interventions. Iman Hakim, M.D., Ph.D., M.P.H., Professor and Dean of the Mel
and Enid Zuckerman College of Public Health and Professor at the Arizona
Cancer Center, University of Arizona, has conducted several human clinical
trials over the past decade on the role both green and black tea may play in
certain cancers. Her latest human clinical trial suggests that bioactive
compounds in tea have a significant effect on genes that impact cancer
susceptibility and repair from environmental insults.
"The good news is that we are seeing that green tea is impacting genes
that play a role in cancer, but we cannot pinpoint who will be responders
versus non-responders at this time," noted Dr. Hakim. "In addition, our
recent preliminary data show a beneficial effect of green tea on lipid profile
among smokers and former smokers. Since there are no known negative effects
of consuming tea, and it may be beneficial, there's no reason not to recommend
drinking it." Dr. Hakim recommends at least four cups per day.
Growing Body of Evidence
The Proceedings of the Fourth International Scientific Symposium on Tea
and Human Health provides the latest scientific update from key research
scientists from top medical institutions in North America, Europe, the Middle
East and Asia, based on their clinical, laboratory, and epidemiological
studies related to the role of tea in promoting healthfulness and reducing the
risk of disease. The ongoing scientific exploration of the health benefits of
drinking tea has led to a growing body of research that points to tea as an
important contributor to overall health. The Proceedings extends the base of
credible, published data supporting the health benefits of tea, encouraging
the scientific community to continue exploring this exciting area.
Please visit http://www.teausa.com/scisymp/publicity.cfm for access to the
studies.
Press Contacts for the Tea Council of the USA, Inc.:
Kevin Hughes
Pollock Communications
646-277-8720
khughes@pollock-pr.com
Melissa McAllister
Pollock Communications
646-277-8711
mmcallister@pollock-pr.com
SOURCE Tea Council of the USA, Inc.
