VOA慢速英语2012--Health Report - Mouth X-Rays and the Brain; Infected Gums Do Not Cause Heart Attacks

Health Report - Mouth X-Rays and the Brain; Infected Gums Do Not Cause Heart Attacks

This is the VOA Special English Health Report.

A new study suggests that dental X-rays may increase the risk of the most common kind of brain tumor¹. However, experts say the risk of these mostly non-cancerous growths is still very small.

The study involved about fourteen hundred patients with brain tumors called meningiomas. They were compared with a control group without brain tumors.

Dr. Elizabeth Claus of Yale University in Connecticut led the study. She says there was a clear relationship between dental X-rays and the brain tumors.

ELIZABETH CLAUS: "We found that the individuals that were diagnosed with meningioma were essentially² about twice as likely to report having a specific type of X-ray, which is very common, a bitewing."

The link was greater with a different kind of imaging, called a panoramic³ X-ray. There was up to five times the risk, depending on age or how often the X-rays were taken.

Dr. Claus points out that in this study, the people were generally in their fifties or older. They were asked to remember X-rays they might have had many years earlier. 

ELIZABETH CLAUS: "There is always some difficulty in people remembering past exposures. And so patients could under- or over-report their dental X-rays. And so you always have to keep that in mind."

Dr. Claus says she does not want to scare people away from dental visits.

ELIZABETH CLAUS: "The big take-home message is, keep going to the dentist. But have a conversation with your dentist about whether you might be able to reduce the number of X-rays that you receive."

Her research paper appears in the American Cancer Society's journal, Cancer.

During dental procedures, and even when people brush their teeth, mouth bacteria often enter the blood system. A popular belief is that gum disease can lead to heart attacks. But last week, Circulation, a journal of the American Heart Association, published a statement saying there is no scientific proof.

The statement says gum disease has not been proven to cause heart disease or stroke. And, it says, treating gum disease has not been proven to prevent them. There is also not enough evidence to know whether brushing and flossing regularly can prevent heart disease.

A committee of heart doctors, dentists and infectious disease specialists considered five hundred journal articles and studies. They say there is not enough evidence at this time to confirm a cause-and-effect relationship between gum disease and heart disease.

Both diseases are often found in the same patient. But the experts say this is possibly because of risk factors common to both diseases. People who do not pay attention to risk factors like smoking, diabetes⁴ or high blood pressure may not pay close attention to their oral health either.

And that's the VOA Special English Health Report. I'm Jim Tedder⁵.

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Contributing: Avi Arditti and Art Chimes

1 tumor   

n.（肿）瘤，肿块(英)tumour

参考例句：

• He was died of a malignant tumor.他死于恶性肿瘤。
• The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。

2 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

3 panoramic   

adj. 全景的

参考例句：

• Most rooms enjoy panoramic views of the sea. 大多数房间都能看到海的全景。
• In a panoramic survey of nature, speed is interesting because it has a ceiling. 概观自然全景，速率是有趣的，因为它有一个上限。

4 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

5 tedder   

n.（干草）翻晒者，翻晒机

参考例句：

• Jim Tedder has more. 吉姆？特德将给我们做更多的介绍。 来自互联网
• Jim Tedder tells us more. 吉姆？泰德给我们带来更详细的报道。 来自互联网