VOA慢速英语2012 Health Report - Rethinking 'Good' Cholesterol; PSA Test Debate

 

Health Report - Rethinking 'Good' Cholesterol¹; PSA Test Debate

This is the VOA Special English Health Report.

A study has raised questions about a widely held belief involving cholesterol. The belief is that high levels of so-called good cholesterol in the blood can reduce the risk of a heart attack.

The medical name for "good" cholesterol is high-density lipoprotein, or HDL. Doctors commonly believe it reduces the risk of heart attack by removing fatty deposits that can block the flow of blood in the arteries² of the heart.

But Dr. Sekar Kathiresan at Massachusetts General Hospital in Boston says the effects of high HDL have never been proven. He says the new study that he and other researchers did suggests that HDL cholesterol does not affect the risk of heart attack.

SEKAR KATHIRESAN: "This has been the major assumption over the last thirty years, that if you raise HDL cholesterol, the risk for heart disease will be lowered. And I think we have now broken that assumption, broken that link using this gene³ variant⁴."

The researchers say about four percent of people have a genetic⁵ change that gives them a naturally high level of HDL. The study found that those who were genetically⁶ "programmed" to have higher HDL levels were just as likely to suffer heart attacks as those who were not.

A second analysis looked at fourteen gene variants⁷ that increase good cholesterol. Dr. Kathiresan says people with the most variants had no more protection against heart attacks than anyone else.

But he says there is no dispute about low-density lipoprotein, or LDL. LDL, the so-called bad cholesterol, causes a buildup of fatty substances inside arteries and increases the risk of heart attack.

Dr. Kathiresan and his colleagues published their findings in the Lancet medical journal.

Another widely held medical belief has also come into question recently. For years, men over the age of forty have been told to get a simple blood test to see if they have prostate cancer. Now, experts on a government committee are advising them not to. Dr. Virginia Moyer heads the United States Preventive Services Task Force.

VIRGINIA MOYER: "Close to two-thirds of older men have prostate cancer and yet the huge majority of them never have a problem from it in their lifetime."

The task force examined two large studies before deciding that treating the cancer found by the PSA test can do more harm than good. Effects of the treatment can include a loss of sexual ability and bladder control, as well as other problems including heart attacks.

Some doctors support the findings of the task force, but others disagree. Urologist Deepak Kapoor says in about twenty years of PSA testing, death rates for prostate cancer have dropped by thirty-eight percent.

And that's the VOA Special English Health Report. I'm Steve Ember.

1 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

2 arteries   

n.动脉( artery的名词复数 )；干线，要道

参考例句：

• Even grafting new blood vessels in place of the diseased coronary arteries has been tried. 甚至移植新血管代替不健康的冠状动脉的方法都已经试过。 来自《简明英汉词典》
• This is the place where the three main arteries of West London traffic met. 这就是伦敦西部三条主要交通干线的交汇处。 来自《简明英汉词典》

3 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

4 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

5 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

6 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

7 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句