VOA标准英语2010年-Popular Supplement Fails to Lower Bloo

A new study of a popular dietary supplement indicates that, while pine bark extract is safe, it has no significant effect on blood pressure or other risk factors for heart disease. This new research seems to contradict evidence from earlier studies.

Previous research has shown an array of benefits from taking pine bark extract, ranging from reducing inflammation to treating skin disorders¹ and menstrual symptoms. It is reported to have antioxidant properties and to help lower blood pressure, as well.

 

To test out some of the claims, Stanford University researcher Randall Stafford and colleagues recruited people who were overweight and had blood pressure slightly higher than normal — in other words, people likely to try a dietary supplement rather than expensive prescription² drugs.

People in the study were randomly⁴ assigned to either take pine bark extract or a look-alike placebo⁵.

After 12 weeks, the researchers found essentially⁶ no benefit from the supplement.

"We in fact found no difference between the pine bark extract group and the placebo group," said Stafford. "There were very small changes in blood pressure. And in fact, there was a slightly greater reduction in blood pressure among the placebo group, but it was a change that could have easily been explained by random³ chance."

Stafford says the results were surprising, because previous studies had shown some cardiovascular benefit. But he noted⁷ that there were problems with the methodology in the earlier studies, which were not placebo-controlled, double-blind trials like his was.

Also, products sold as "pine bark extract" can be made in a variety of ways and are not all the same, since these sorts of nutritional⁸ supplements are only loosely regulated, at least here in the U.S.

"There are a number of different pine bark extracts out on the market. They are extracted or derived⁹ in different ways. It is possible that other pine bark might have benefits where this one doesn't," he said.

In the United States and many other countries, government officials don't require natural dietary supplements to be proven safe and effective, the way other drugs are.

Stafford says his study illustrates¹⁰ how flimsy the scientific basis is for claims made by sellers of and advocates for many different supplements.

"Much of the expenditure¹¹ on dietary supplements are for products that really don't have rigorous data supporting their use."

The study by Stanford researcher Randall Stafford and colleagues is published in the American Medical Association journal, Archives of Internal Medicine.

1 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

2 prescription   

n.处方，开药；指示，规定

参考例句：

• The physician made a prescription against sea- sickness for him.医生给他开了个治晕船的药方。
• The drug is available on prescription only.这种药只能凭处方购买。

3 random   

adj.随机的；任意的；n.偶然的(或随便的)行动

参考例句：

• The list is arranged in a random order.名单排列不分先后。
• On random inspection the meat was found to be bad.经抽查，发现肉变质了。

4 randomly   

adv.随便地，未加计划地

参考例句：

• Within the hot gas chamber, molecules are moving randomly in all directions. 在灼热的气体燃烧室内，分子在各个方向上作无规运动。 来自辞典例句
• Transformed cells are loosely attached, rounded and randomly oriented. 转化细胞则不大贴壁、圆缩并呈杂乱分布。 来自辞典例句

5 placebo   

n.安慰剂；宽慰话

参考例句：

• The placebo has been found to work with a lot of different cases.人们已发现安慰剂能在很多不同的病例中发挥作用。
• The placebo effect refers to all the observable behaviors caused by placebo.安慰剂效应是指由安慰剂所引起的可观察的行为。

6 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。

7 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

8 nutritional   

adj.营养的，滋养的

参考例句：

• A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
• The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。

9 derived   

vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取

参考例句：

• Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
• He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》

10 illustrates   

给…加插图( illustrate的第三人称单数 )； 说明； 表明； （用示例、图画等）说明

参考例句：

• This historical novel illustrates the breaking up of feudal society in microcosm. 这部历史小说是走向崩溃的封建社会的缩影。
• Alfred Adler, a famous doctor, had an experience which illustrates this. 阿尔弗莱德 - 阿德勒是一位著名的医生，他有过可以说明这点的经历。 来自中级百科部分

11 expenditure   

n.(时间、劳力、金钱等)支出；使用，消耗

参考例句：

• The entry of all expenditure is necessary.有必要把一切开支入账。
• The monthly expenditure of our family is four hundred dollars altogether.我们一家的开销每月共计四百元。