From: Doug Skrecky (oberon@vcn.bc.ca)
Date: Sun Apr 27 2003 - 11:44:16 MDT
Newsgroups: alt.health,sci.life-extension,misc.health.alternative,sci.med
Study: Tea sharpens body's defense against germs
By Paul Recer, Associated Press, 4/21/2003 17:05
WASHINGTON (AP) A wee cuppa tea may help keep the doctor away.
A new study finds that tea boosts the body's defenses against
infection and contains a substance that might be turned into a drug to
protect against disease, researchers say. Coffee does not have the
same effect, they say.
A component in tea was found in laboratory experiments to prime the
immune system to attack invading bacteria, viruses and fungi,
according to a study in the Proceedings of the National Academy of
Sciences released Monday.
A second experiment, using human volunteers, showed that immune system
blood cells from tea drinkers responded five times faster to germs
than did the blood cells of coffee drinkers.
FULL REPORT:
http://www.boston.com/dailynews/111/wash/Study_Tea_sharpens_body_s_defe:.shtml
Same topic from the BBC:
http://news.bbc.co.uk/1/hi/health/2955491.stm
Tea helps fight off infections
Drinking tea may prime the immune system to fight infections and even
cancer, researchers have said.
The drink contains particular chemicals which are also present in some
bacteria, tumour cells, parasites and funghi.
Because these are present in tea, the body is exposed to them so it
can build up a defence against them if it comes up against them as
part of a disease.
The chemicals are called alkylamine antigens.
US researchers looked at the effect of the antigens on gamma-delta T
cells in the immune system, which act as a first line of defence
against infection.
Human gamma-delta T cells were exposed to an alkylamine antigen.
They were then exposed to bacteria to simulate an infection.
Those cells which had been "primed" fought back against the bacteria,
by multiplying up to 10 times and secreting disease-fighting
chemicals.
Cells which had not previously exposed to an alkylamine antigen showed
no significant response to the simulated infection.
Tea versus coffee
The researchers from Brigham and Women's Hospital and Harvard Medical
School in Boston and the University of New Hampshire, Durham, then
looked to see if the results were replicated in tea drinkers.
They asked volunteers to drink either five small cups of black tea or
coffee daily for up to four weeks.
Green and black teas contain an alkylamine antigen and its precursor,
L-theanine, but coffee does not.
After two weeks, gamma-delta T cells from tea drinkers were better
able to produce disease-fighting chemicals, but coffee drinkers were
not.
The researchers say this suggests that drinking tea can promote a
strong immune response, in addition to other known health benefits.
Tenuous
Dr Emma Knight, science information officer at Cancer Research UK told
BBC News Online: "The potential health benefits of tea have been
discussed for many years, primarily focusing on its anti-oxidant
activities.
"This study suggests that the nation's favourite drink might offer yet
another, unforeseen, benefit to our health."
She added: "It builds upon previous research, published in 1999, which
showed that these molecules could help immune cells grown in the
laboratory fight infections.
"The researchers now have early results suggesting that alkylamines in
tea might be able to boost our natural immune responses to infections.
"Intriguingly, some cancers also contain alkylamines, opening up the
possibility that exposure to these molecules could help our immune
systems fight cancer.
"This link is currently very tenuous and further research is needed to
address the role of these molecules in cancer."
Bill Gorman, executive director of the Tea Council, said the research
was added evidence of the benefits of drinking tea.
He said: "Next to water, tea is the most consumed beverage in the
world, and as a result, has attracted an enormous quantity of research
over the years.
"There is a huge body of scientific evidence showing that tea can make
a significant contribution to a healthy lifestyle, and in particular,
in the areas of cardiovascular health and dental hygiene".
But he added: "As with all science, there is some way to go before
conclusive proof is established, but the message emerging for the
scientific research into tea is very encouraging indeed."
The research is published in the Proceedings of the National Academy
of Science.
Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/health/2955491.stm
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