Tea May Help Fight Infection

 

Broadcast: April 30, 2003
By Nancy Steinbach

This is the VOA Special English Health Report.
American researchers say drinking tea may help strengthen the body's defense¹ system against infection. Doctors at Brigham and Women's Hospital in Boston, Massachusetts, did the study.
The team studied a chemical found in black, green, oolong1 and pekoe2 tea. This chemical is an amino acid called L-theanine. The scientists say it may increase the strength of gamma delta² T cells. That's the letter T, not the drink. Gamma delta T cells are part of the body's defenses.
First, the researchers mixed some of these cells with antigens found in the amino acid. Antigens help the body react to infection. Then the scientists added some bacteria. Within twenty-four hours, the cells produced a lot of interferon, a substance that fights infection. Cells not mixed with the antigens did not produce interferon.
In the second part of the study, eleven people drank five to six cups of black tea every day. Ten other people drank the same amount of instant coffee. That is dried coffee mixed with hot water.
Two weeks later, and again two weeks after that, the researchers tested the blood of all twenty-one people. They also looked at what happened when they added bacteria to the blood cells. They found that the tea drinkers produced five times more interferon after they started drinking tea. The coffee drinkers did not produce interferon.
The findings appear in the Proceedings³ of the National Academy of Sciences. The National Institutes of Health and the Arthritis⁴ Foundation provided money for the research.
Doctor Jack⁵ Bukowski led the study. He says the antigens added to the gamma delta T cells were responsible for the increased reaction to the bacteria. He says the study also showed that the cells were able to remember the bacteria and fight them again the next time.
Earlier research already has found that tea can help prevent heart disease and cancer. Doctor Bukowski says the new study must be repeated with more people. If the findings are confirmed, he says, then tea drinking might also help protect against bacterial⁶ infections. He says the amino acid L-theanine could be removed from tea and used as a drug to strengthen the body's defenses.
This VOA Special English Health Report was written by Nancy Steinbach.

1. oolong [5u:lCn] n. 乌龙茶
2. pekoe [5pIk[u] n. 香红茶，白毫（指印度、斯里兰卡等国用茶树嫩叶制成的高级红茶）

1 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

2 delta   

n.（流的）角洲

参考例句：

• He has been to the delta of the Nile.他曾去过尼罗河三角洲。
• The Nile divides at its mouth and forms a delta.尼罗河在河口分岔，形成了一个三角洲。

3 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

4 arthritis   

n.关节炎

参考例句：

• Rheumatoid arthritis has also been linked with the virus.风湿性关节炎也与这种病毒有关。
• He spent three months in the hospital with acute rheumatic arthritis.他患急性风湿性关节炎，在医院住了三个月。

5 jack   

n.插座，千斤顶，男人；v.抬起，提醒，扛举；n.（Jake）杰克

参考例句：

• I am looking for the headphone jack.我正在找寻头戴式耳机插孔。
• He lifted the car with a jack to change the flat tyre.他用千斤顶把车顶起来换下瘪轮胎。

6 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。