有益胆固醇和PSA测试受到质疑

This is the VOA Special English Health Report.
这里是美国之音慢速英语健康报道。

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.
一项研究对一种涉及胆固醇的普遍观点提出了质疑。这种观点认为，血液中的有益胆固醇水平高能够降低心脏病发作的风险。

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 arteries of the heart.
这种有益胆固醇的医学名称是高密度脂蛋白（以下简称HDL）。医生们普遍认为，它能通过带走阻塞心脏动脉血液流动的脂肪沉积，降低心脏病发作的风险。
 
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.
但波士顿市马萨诸塞总医院的谢卡尔·凯瑟雷森（Sekar Kathiresan）表示，HDL含量高的影响从未被证实。他表示，自己和其他研究人员进行的这项新研究证实，HDL胆固醇对心脏病发作的风险没有影响。

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 gene variant."
凯瑟雷森：“这是过去30年的一种主流假设，如果提高HDL胆固醇含量，心脏病风险将会降低。而我认为，我们现在已经通过分析基因变异打破了这种假设，打破了这两者的联系。”

The researchers say about four percent of people have a genetic change that gives them a naturally high level of HDL. The study found that those who were genetically "programmed" to have higher HDL levels were just as likely to suffer heart attacks as those who were not.
研究人员称，约4%的人拥有一种遗传变异，使得他们生来HDL水平就高。研究发现，这种天生就HDL水平更高的人和普通人同样会患心脏病。

A second analysis looked at fourteen gene variants that increase good cholesterol. Dr. Kathiresan says people with the most variants had no more protection against heart attacks than anyone else.
第二项分析着眼于能够提升有益胆固醇含量的14种基因变异。凯瑟雷森表示，拥有基因变异最多的人群与其他人相比，并未能更好地预防心脏病发作。

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.
但他表示，有一点没有争议，低密度脂蛋白，也就是所谓的有害胆固醇（以下简称LDL），会导致动脉内的脂肪物质堆积，提高心脏病发作的风险。

Dr. Kathiresan and his colleagues published their findings in the Lancet medical journal.
凯瑟雷森医生及其同事将他们的这一研究结果发表在《柳叶刀》医学杂志上。

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.
另一种普遍医学观点最近也受到了质疑。多年来，40岁以上男子一直被告知进行一种简单的血液测试，看他们是否患有前列腺癌。目前，某政府委员会的专家建议他们不要这么做。弗吉尼亚·莫耶医生（Virginia Moyer）负责美国预防医学特别委员会。

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."
莫耶：“将近2/3的老年男子患有前列腺癌，但他们中的绝大多数人终其一生都未因为前列腺癌产生什么问题。”

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.
在断定对经由PSA测试发现的前列腺癌患者的治疗弊大于利前，该委员会审查了两项大型研究。这种治疗的后果包括丧失性能力和膀胱控制，以及包括心脏病发作在内的其它问题。