Green tea may fight allergies

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Green Tea May Fight Allergies

 

Allergy sufferers may want to add green tea to their sniffle-fighting

arsenal. New evidence suggests that drinking the popular brew may provide some

relief. Researchers in Japan identified a compound in green tea that, in

laboratory

tests, blocks a key cell receptor involved in producing an allergic response.

The compound, methylated epigallocatechin gallate (EGCG), may have a similar

effect in humans, they say. Their study will be described in the Oct. 9 print

issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed

publication of the American Chemical Society, the world's largest scientific

society.

 

 

 

Although similar compounds in green tea have previously been shown to be

anti-allergenic, this particular compound appears to be the most potent, the

researchers say.

 

" Green tea appears to be a promising source for effective anti-allergenic

agents, " says Hirofumi Tachibana, the study's chief investigator and an

associate

professor of chemistry at Kyushu University in Fukuoka, Japan. " If you have

allergies, you should consider drinking it. "

 

For years, people have been drinking tea to fight the sneezing, coughing and

watery eyes that are characteristic of colds and allergies. The new study adds

to a small but growing body of scientific evidence from both cell and animal

studies that it may actually work, particularly green tea.

 

No one has proven, however, that anti-allergenic compounds found thus far

have an actual therapeutic effect in humans who ingest green tea. If it works,

the brew may be useful against a wide range of allergens, including pollen,

dust, pet dander and certain chemicals, Tachibana says. Further studies are

needed.

 

EGCG is one of the most abundant and biologically active antioxidants found

in tea. It is believed to be responsible for tea's beneficial health effects.

The compound is found in higher concentrations in green tea, the least

processed of teas, than in black and oolong varieties.

 

Previous studies have shown that EGCG fights allergic reactions in rodents

that were given the compound orally, but researchers are just beginning to

understand how it might work.

 

It now appears that the compound works by blocking the production of

histamine and immunoglobulin E (IgE), two compounds in the body that are chiefly

involved in triggering and sustaining allergic reactions, Tachibana says.

 

The current study shows, for the first time, that a methylated form of EGCG

can block the IgE receptor, which is a key receptor involved in an allergic

response. The effect was demonstrated using human basophils, which are blood

cells that release histamine.

 

Methylated EGCG appears to elicit a stronger anti-allergenic response than

normal EGCG, making it the strongest anti-allergen compound found in tea, the

researchers say.

 

Although promising against allergies, no one knows how much green tea is

needed to have a therapeutic effect, or which green tea varieties work best, the

researchers add. They are currently looking for additional anti-allergenic

compounds in the tea.

 

Green tea has been called the second-most consumed beverage in the world,

behind water. It is very popular in Japan, and has a growing following in the

United States, where black tea is favored. Tachibana's study adds to an

expanding

list of the potential health benefits offered by green tea. In addition to

allergies, it is reported to fight cancer, cardiovascular disease, arthritis and

tooth decay.

 

Approximately 50 million people in this country suffer from some type of

allergy. Until studies are done to determine whether green tea is actually

beneficial to humans with allergies, experts urge consumers to see their doctor

for

the best advise on treatment options. Among those options: minimizing or

avoiding suspected allergens (i.e. dust, pollen, certain foods). Exercise and

proper

diets are also thought to alleviate the effect of allergies.

 

Funding for this study was provided in part by grants from the Program for

Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN).

 

Dr. Tachibana's associates in this study were Yoshinori Fujimura and Koji

Yamada of Kyushi University, Mari Maeda-Yamamoto of the National Research

Institute of Vegetables and Tea Sciences, and Toshio Miyase and Mitsuaki Sano of

the

University of Shizuoka.

 

 

 

 

 

Hirofumi Tachibana, Ph.D., is an associate professor of chemistry in the

department of bioscience and biotechnology at Kyushu University in Fukuoka,

Japan

 

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