VOA慢速英语2010年-SCIENCE IN THE NEWS - Getting to the H

STEVE EMBER:

This is the VOA Special English program SCIENCE IN THE NEWS. I'm Steve Ember.

BARBARA KLEIN:

And I'm Barbara Klein. This week, we will tell how less salt can lead to better health. We will also tell about the helpful effects of omega-three fatty acids. And, we will share details of recent studies about antidepressant drugs and running shoes.

(MUSIC)

STEVE EMBER:

A small reduction in salt in your diet can be a big help to your heart. A new study used a computer model to predict how just three grams less a day would affect heart disease in the United States. The result was thirteen percent fewer heart attacks. It would lead to eight percent fewer strokes and four percent fewer deaths. The study predicted eleven percent fewer new cases of heart disease. And, two hundred forty billion dollars in health care savings¹.

The New England Journal of Medicine published a report about the study. The lead writer was Kirsten Bibbins-Domingo of the University of California at San Francisco. She says people would not even notice a difference in taste with three grams less salt per day.

BARBARA KLEIN:

Each gram of salt contains four hundred milligrams of sodium². The federal government says the average American man swallows ten grams of salt a day.

But the American Heart Association advises no more than three grams for healthy people. It says salt in the American diet has increased fifty percent since the nineteen seventies, while blood pressures have also risen. Less salt can mean a lower blood pressure.

New York City Mayor Michael Bloomberg is leading an effort called the National Salt Reduction Initiative. The idea is to put pressure on food companies and restaurants. Critics call it government interference. Mayor Bloomberg has already succeeded in other areas, like requiring fast food businesses in the city to list calorie information.

(MUSIC)

STEVE EMBER:

Scientists know that omega-three fatty acids in fish oil can help people with heart disease live longer. Cold water fish like salmon³ and tuna contain omega-three fatty acids. These fatty acids are mainly found in fish oil. They are also in some vegetable oils and foods like walnuts⁴. Earlier studies showed that omega-three fatty acids can decrease the risk of coronary artery⁵ disease. But until now, no one knew why they are so helpful.

Coronary artery disease is a leading cause of death throughout the world. The disease results when plaque⁶ builds up inside coronary arteries⁷ and blocks the flow of blood to the heart.

BARBARA KLEIN:

Ramin Farzaneh-Far is an assistant professor of medicine at the University of California in San Francisco. He led a study to see if there might be a link between omega-three acids and the aging of cells. To do, his team examined telomeres -- the protective covers on the ends of chromosomes⁸. Scientists believe that the shortening of telomeres over time leads to cell death.

His research team measured the length of telomeres in blood cells from six hundred heart disease patients. The patients all had taken part in the Heart and Soul Study, which lasted from two thousand to two thousand two. Blood from the patients was tested for omega-three fatty acids.

Doctor Farzaneh-Far says his team wanted to see if there was any link between the fatty acid levels and the change in telomere length over time.

RAMIN FARZANEH-FAR: "Patients with the highest levels of omega-three fish oils were found to display the slowest decrease in telomere length, whereas those with the lowest levels of omega-three fish oils in the blood had the fastest rate of telomere shortening, suggesting that these patients were aging faster than those with the higher fish oil levels in their blood."

STEVE EMBER:

The Journal of the American Medical Association published the results of the study. The team did not study how much fish oil the patients were receiving, so the amount needed to have an effect is unclear.

Doctor Farzaneh-Far says the results confirm what the American Heart Association advises for patients with coronary artery disease. That is to eat fish two times a week, or have at least one gram a day of omega-three fish oil. Fish oil is not the only thing that can affect telomere length. But the researchers say it does have an influence. The researchers did not study the effect of omega-three fatty acids in people without heart disease. But they note that telomere shortening happens in everyone.

(MUSIC)

BARBARA KLEIN:

Antidepressant drugs are often used to treat depression. They also are among the most commonly prescribed medicines in the United States. One study found that at least twenty-seven million Americans use antidepressants on doctors' orders. That number is two times what it was in the nineteen nineties.

Recently, researchers reported making discoveries that may change the way antidepressants are given to patients. Researchers at the University of Pennsylvania studied information from earlier studies about two drugs: paroxentine and imipramine. Both are commonly used against depression.

STEVE EMBER:

The studies involved more than seven hundred patients with severe, moderate and mild forms of depression. Some of the patients were given antidepressants. Others were given placebos¹⁰ -- harmless substances used in place of medication. The Journal of the American Medical Association reported on the results of the study. Jay Fournier was the lead writer.

JAY FOURNIER "What we found was that patients who are on the lower end of severity, the medications were not doing much more than the placebo⁹ was. For patients at the higher end of severity, the medications had a very potent¹¹ effect."

Doctors have been divided about how to treat patients with less serious signs of depression. The study does not offer suggestions for treatment, but it may affect treatment methods. The results may influence patients with milder signs of depression to seek other kinds of treatment. This is especially true since some antidepressants can have undesirable¹² side effects.

BARBARA KLEIN:

Antidepressant medicines can be extremely helpful for people with severe depression. This level of depression can make it difficult to work, sleep and eat normally.

Stuart Sotsky is a psychiatrist¹³ with George Washington University in Washington, D.C. He completed one of the studies used in the research. Doctor Sotsky says antidepressants can still help some moderately depressed¹⁴ patients. But his study showed that many others could do just as well with exercise, support groups and self-help methods.

(MUSIC)

STEVE EMBER:

Finally, two studies are suggesting that modern running shoes could increase the risk of injuries to runners. One study involved sixty-eight healthy young women and men who ran at least twenty-four kilometers a week. The runners were observed on a treadmill¹⁵. Sometimes they wore running shoes while using the equipment. Other times the runners ran barefoot.

Researchers from the University of Colorado and the University of Virginia worked with a Virginia company -- JKM Technologies.

The researchers found that running shoes create more stress that could damage knees, hips¹⁶ and ankle joints¹⁷ than running barefoot. They observed that the effect was even greater than the effect reported earlier for walking in high heels.

The study appeared in the official scientific publication of the American Academy of Physical Medicine.

BARBARA KLEIN:

The other study appeared in Nature magazine. It compared runners in the United States and Kenya. The researchers were from Harvard University in Massachusetts, Moi University in Kenya and the University of Glasgow in Scotland. They divided the runners into three groups. One group had always run shoeless. Another group had always run with shoes. The third group had changed to shoeless running.

Runners who wear shoes usually come down heel first. That puts great force on the back of the foot. But the study found that barefoot runners generally land on the front or middle of their foot. That way they ease into their landing and avoid striking their heel.

STEVE EMBER:

Harvard's Daniel Lieberman led the study. He says the way most running shoes are designed may explain why those who wear them land on their heels. The heel of the shoe is bigger and heavier than other parts of the shoe, so it would seem more likely to come down first. Also, the heel generally has thick material under it to soften¹⁸ landings.

But the researchers do not suggest that runners immediately start running barefoot. They say it takes some training. And, there can be risks, like running when your feet are too cold to feel if you get injured.

(MUSIC)

BARBARA KLEIN:

This SCIENCE IN THE NEWS was written by Caty Weaver¹⁹ and Brianna Blake. Our producer was Lawan Davis. I'm Barbara Klein.

STEVE EMBER:

And, I'm Steve Ember. Join us again next week for more news about science in Special English on the Voice of America.
 

1 savings   

n.存款，储蓄

参考例句：

• I can't afford the vacation,for it would eat up my savings.我度不起假，那样会把我的积蓄用光的。
• By this time he had used up all his savings.到这时，他的存款已全部用完。

2 sodium   

n.（化）钠

参考例句：

• Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。
• Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

3 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

4 walnuts   

胡桃（树）( walnut的名词复数 )； 胡桃木

参考例句：

• Are there walnuts in this sauce? 这沙司里面有核桃吗？
• We ate eggs and bacon, pickled walnuts and cheese. 我们吃鸡蛋，火腿，腌胡桃仁和干酪。

5 artery   

n.干线，要道；动脉

参考例句：

• We couldn't feel the changes in the blood pressure within the artery.我们无法感觉到动脉血管内血压的变化。
• The aorta is the largest artery in the body.主动脉是人体中的最大动脉。

6 plaque   

n.饰板，匾，(医)血小板

参考例句：

• There is a commemorative plaque to the artist in the village hall.村公所里有一块纪念该艺术家的牌匾。
• Some Latin words were engraved on the plaque. 牌匾上刻着些拉丁文。

7 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》

8 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

9 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。

10 placebos   

n.（给无实际治疗需要者的）安慰剂( placebo的名词复数 )；安慰物；宽心话；（试验药物用的）无效对照剂

参考例句：

• But, eventually, I think they were just kind of like placebos. 但是后来，我想它们只是安慰剂（安慰剂：没有任何药效的药） 来自电影对白
• But comparable numbers of those who received placebos also improved. 但是吃安慰剂的人的病情也改善了。 来自互联网

11 potent   

adj.强有力的，有权势的；有效力的

参考例句：

• The medicine had a potent effect on your disease.这药物对你的病疗效很大。
• We must account of his potent influence.我们必须考虑他的强有力的影响。

12 undesirable   

adj.不受欢迎的，不良的，不合意的，讨厌的；n.不受欢迎的人，不良分子

参考例句：

• They are the undesirable elements among the employees.他们是雇员中的不良分子。
• Certain chemicals can induce undesirable changes in the nervous system.有些化学物质能在神经系统中引起不良变化。

13 psychiatrist   

n.精神病专家；精神病医师

参考例句：

• He went to a psychiatrist about his compulsive gambling.他去看精神科医生治疗不能自拔的赌瘾。
• The psychiatrist corrected him gently.精神病医师彬彬有礼地纠正他。

14 depressed   

adj.沮丧的，抑郁的，不景气的，萧条的

参考例句：

• When he was depressed,he felt utterly divorced from reality.他心情沮丧时就感到完全脱离了现实。
• His mother was depressed by the sad news.这个坏消息使他的母亲意志消沉。

15 treadmill   

n.踏车；单调的工作

参考例句：

• The treadmill has a heart rate monitor.跑步机上有个脉搏监视器。
• Drugs remove man from the treadmill of routine.药物可以使人摆脱日常单调的工作带来的疲劳。

16 hips   

abbr.high impact polystyrene 高冲击强度聚苯乙烯，耐冲性聚苯乙烯n.臀部( hip的名词复数 )；[建筑学]屋脊；臀围（尺寸）；臀部…的

参考例句：

• She stood with her hands on her hips. 她双手叉腰站着。
• They wiggled their hips to the sound of pop music. 他们随着流行音乐的声音摇晃着臀部。 来自《简明英汉词典》

17 joints   

接头( joint的名词复数 )； 关节； 公共场所（尤指价格低廉的饮食和娱乐场所） （非正式）； 一块烤肉 （英式英语）

参考例句：

• Expansion joints of various kinds are fitted on gas mains. 各种各样的伸缩接头被安装在煤气的总管道上了。
• Expansion joints of various kinds are fitted on steam pipes. 各种各样的伸缩接头被安装在蒸气管道上了。

18 soften   

v.(使)变柔软；(使)变柔和

参考例句：

• Plastics will soften when exposed to heat.塑料适当加热就可以软化。
• This special cream will help to soften up our skin.这种特殊的护肤霜有助于使皮肤变得柔软。

19 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。