2007年VOA标准英语-Study: Antioxidant Vitamins May Increase Health

By Jessica Berman
Washington
28 February 2007

According to the results of a new study, antioxidant vitamin supplements taken by people to promote their health may actually shorten their life.  The findings were based on a review of dozens of studies on the health effects of vitamin supplements.  VOA's Jessica Berman reports.

The study by Danish researchers analyzed¹ the data of 68 anti-oxidant studies involving almost a quarter of a million people.  About half took beta carotene, and vitamins A, E and C supplements, thinking the vitamin pills improved their health.

The supplement-takers in the studies were compared to groups of participants who did not take antioxidants.

The Danish investigators² found that on average, those taking vitamin A increased their risk of death by 16 percent; beta-carotene supplements taken regularly increased the risk of premature³ death by seven percent and vitamin E supplements increased the risk by four percent.  The researchers found that vitamin C did not have an effect one way or the other.

The results of the study were published in the Journal of the American Medical Association (JAMA).

Edgar Miller⁴ is a professor of medicine at Hopkins University School of Public Health in Baltimore, Maryland.  Miller called the study extremely well done and one that would be hard to replicate⁵ given its size and scope. 

The study looked at the effects of supplements that can be purchased in the average health food store, like vitamin E, which Miller says can be up to 50 times the amount found in a healthy diet.

Those kinds of mega-doses, says Miller, might do more harm than good.

"The emerging evidence that giving high dose supplements like this can actually displace other natural antioxidants," he said.  "It can affect your normal cell signaling where if you have a damaged cell that is maybe is pre-cancerous typically what happens it sends out these signals that it needs to be taken care of by your own immune system.  But perhaps these anti-oxidants [from supplements] are blocking that signal."

Natural anti-oxidants neutralize⁶ free radicals⁷, cell-damaging molecules⁸ that are produced in the body as a result of the energy producing process. 

Balz Frei is director of the Linus Pauling Institute at Oregon State University, which studies the role of vitamins and minerals in preventing disease.  Frei says the study was flawed.

"This study really does nothing to advance the knowledge in the field.  It does not do anything to help consumers decide what they should do," he said.  "And it does not reveal the true health effects of anti-oxidants, whether beneficial or otherwise."

Frei says additional, large scale studies need to be done that measure the benefits of vitamin supplements, and they should be compared head to head to studies such as the one that was just published. 

In the meantime, Miller thinks people ought to proceed with caution if they are taking vitamin supplements or are thinking about it.

"If it is anecdotal reports or if it is a nutraceutical or pharmaceutical⁹ company that is promoting the use of it, you really need to look at the evidence whether it would benefit or not.  I think this study in JAMA shows that in this large number of trials it does not prolong life.  In fact, it may actually shorten life."

Miller believes there will now be medical research into why anti-oxidant supplements appear to cause harm.

1 analyzed   

v.分析( analyze的过去式和过去分词 )；分解；解释；对…进行心理分析

参考例句：

• The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
• The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》

2 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

3 premature   

adj.比预期时间早的；不成熟的，仓促的

参考例句：

• It is yet premature to predict the possible outcome of the dialogue.预言这次对话可能有什么结果为时尚早。
• The premature baby is doing well.那个早产的婴儿很健康。

4 miller   

n.磨坊主

参考例句：

• Every miller draws water to his own mill.磨坊主都往自己磨里注水。
• The skilful miller killed millions of lions with his ski.技术娴熟的磨坊主用雪橇杀死了上百万头狮子。

5 replicate   

v.折叠，复制，模写；n.同样的样品；adj.转折的

参考例句：

• The DNA of chromatin must replicate before cell division.染色质DNA在细胞分裂之前必须复制。
• It is also easy to replicate,as the next subsection explains.就像下一个小节详细说明的那样，它还可以被轻易的复制。

6 neutralize   

v.使失效、抵消，使中和

参考例句：

• Nothing could neutralize its good effects.没有什么能抵消它所产生的好影响。
• Acids neutralize alkalis and vice versa.酸能使碱中和碱，亦能使酸中和。

7 radicals   

n.激进分子( radical的名词复数 )；根基；基本原理；[数学]根数

参考例句：

• Some militant leaders want to merge with white radicals. 一些好斗的领导人要和白人中的激进派联合。 来自《简明英汉词典》
• The worry is that the radicals will grow more intransigent. 现在人们担忧激进分子会变得更加不妥协。 来自辞典例句

8 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

9 pharmaceutical   

adj.药学的，药物的；药用的，药剂师的

参考例句：

• She has donated money to establish a pharmaceutical laboratory.她捐款成立了一个药剂实验室。
• We are engaged in a legal tussle with a large pharmaceutical company.我们正同一家大制药公司闹法律纠纷。