美国国家公共电台 NPR How Helpful Would A Genetic Test For Obesity Risk Be?

 

RACHEL MARTIN, HOST:

Now, if you're worried about developing heart disease, you could take a blood test to see if you have high cholesterol¹. But there hasn't been a test to check your risk for obesity². Researchers have now developed an experimental genetic³ scan to identify people likely to become severely⁴ overweight. NPR science correspondent Richard Harris reports.

RICHARD HARRIS, BYLINE⁵: The current obesity epidemic⁶ shows that our environments and habits are driving a lot of obesity. But genes⁷ play an important role, as well - and not just a few genes, apparently⁸ a whole bunch of them. Each makes a tiny contribution. But collectively, they can influence everything from appetite control to metabolism⁹.

Sekar Kathiresan, a cardiologist and geneticist at the Broad Institute at Harvard and MIT, set out to see whether his team could find a bunch of these genetic variants¹⁰ and add up their effects to create a test to predict who is at highest risk of obesity.

SEKAR KATHIRESAN: This information, this genetics could explain why somebody's so big, why they have so much trouble keeping their weight down.

HARRIS: Kathiresan and his colleagues identified more than 2 million DNA¹¹ variations linked to obesity. He figures most of them are irrelevant¹². But his hunch¹³ is - hidden somewhere in there are a few thousand meaningful variants. And his risk score based on the 2 million variants does identify people who are most at risk of becoming severely obese¹⁴.

KATHIRESAN: The impact of the genetics starts very early in life, in the preschool years, around the age of 3.

HARRIS: That means prevention efforts are more likely to succeed if they start in childhood. Kathiresan has a more philosophical¹⁵ takeaway from his work as well.

KATHIRESAN: This work hopefully will destigmatize obesity and make it very similar to every other disease, which is a combination of both lifestyle and genetics.

HARRIS: The findings were recently reported in the journal Cell. A lot of the broad conclusions aren't new. Scientists already knew that obesity has a strong genetic component¹⁶, and other studies show that obese children are at high risk for becoming obese adults. Cecile Janssens, an epidemiologist at Emory University, doesn't think much of this strategy of adding up the minuscule¹⁷ risks from millions of genetic variants to come up with a cumulative¹⁸ risk score.

CECILE JANSSENS: We do not know for sure whether all these variants really matter.

HARRIS: So what is the value of doing something like this then?

JANSSENS: I have no clue. I have no idea.

HARRIS: This type of analysis doesn't reveal anything about the individual genes that are contributing to obesity, which means you can't use it to understand the underlying¹⁹ biology. If obesity were a rare disease, a test could be useful to identify people at elevated risk. But since it affects 40% of Americans, Janssens says really prevention efforts should include everybody.

JANSSENS: It is not really answering a very relevant question from the biological perspective and not really answering a very relevant question from a clinical perspective.

HARRIS: Janssens is among a group of scientists informally rebelling against the gene-centric way of looking at disease. It's frustrating²⁰ for them to see so much effort poured into this kind of genetics work since the results often don't lead to meaningful actions. Theresa Marteau, who directs the Behaviour and Health Research Unit at the University of Cambridge, says scientists had hoped that using genetic information to inform people that they're at high risk of a disease would make a difference - but no.

THERESA MARTEAU: This kind of personalized risk information has little if no impact on people's actual behavior.

HARRIS: Ewan Birney, who heads the European Bioinformatics Institute, says the critics have a point.

EWAN BIRNEY: One needs to do more than just be able to show a strong statistical²¹ association. One really needs to be able to show that you can use that to do an intervention²².

HARRIS: There are other cases where you can do that, he says - for example, by using this kind of risk score to identify people who don't know that they could benefit from cholesterol-lowering drugs. So this strategy has its place, he says, along with its limitations.

Richard Harris, NPR News.

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 obesity   

n.肥胖，肥大

参考例句：

• One effect of overeating may be obesity.吃得过多能导致肥胖。
• Sugar and fat can more easily lead to obesity than some other foods.糖和脂肪比其他食物更容易导致肥胖。

3 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。

4 severely   

adv.严格地；严厉地；非常恶劣地

参考例句：

• He was severely criticized and removed from his post.他受到了严厉的批评并且被撤了职。
• He is severely put down for his careless work.他因工作上的粗心大意而受到了严厉的批评。

5 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

6 epidemic   

n.流行病；盛行；adj.流行性的，流传极广的

参考例句：

• That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。
• The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。

7 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

8 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

9 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

10 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

11 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

12 irrelevant   

adj.不恰当的，无关系的，不相干的

参考例句：

• That is completely irrelevant to the subject under discussion.这跟讨论的主题完全不相关。
• A question about arithmetic is irrelevant in a music lesson.在音乐课上，一个数学的问题是风马牛不相及的。

13 hunch   

n.预感，直觉

参考例句：

• I have a hunch that he didn't really want to go.我有这么一种感觉，他并不真正想去。
• I had a hunch that Susan and I would work well together.我有预感和苏珊共事会很融洽。

14 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

15 philosophical   

adj.哲学家的，哲学上的，达观的

参考例句：

• The teacher couldn't answer the philosophical problem.老师不能解答这个哲学问题。
• She is very philosophical about her bad luck.她对自己的不幸看得很开。

16 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

17 minuscule   

adj.非常小的；极不重要的

参考例句：

• The human race only a minuscule portion of the earth's history.人类只有占有极小部分地球历史。
• As things stand,Hong Kong's renminbi banking system is minuscule.就目前的情况而言，香港的人民币银行体系可谓微不足道。

18 cumulative   

adj.累积的，渐增的

参考例句：

• This drug has a cumulative effect.这种药有渐增的效力。
• The benefits from eating fish are cumulative.吃鱼的好处要长期才能显现。

19 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。

20 frustrating   

adj.产生挫折的，使人沮丧的，令人泄气的v.使不成功( frustrate的现在分词 )；挫败；使受挫折；令人沮丧

参考例句：

• It's frustrating to have to wait so long. 要等这么长时间，真令人懊恼。
• It was a demeaning and ultimately frustrating experience. 那是一次有失颜面并且令人沮丧至极的经历。 来自《简明英汉词典》

21 statistical   

adj.统计的，统计学的

参考例句：

• He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
• They're making detailed statistical analysis.他们正在做具体的统计分析。

22 intervention   

n.介入，干涉，干预

参考例句：

• The government's intervention in this dispute will not help.政府对这场争论的干预不会起作用。
• Many people felt he would be hostile to the idea of foreign intervention.许多人觉得他会反对外来干预。