閱讀理解

第十六篇Eat to Live

A meager diet may give you health and long life, but it's not much fun - and it might not even be necessary. We may be able to hang on to most of that youthful vigor even if we don't start to diet until old age.

Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation won't reverse other damage caused by time for the mouse, but could help its liver metabolize drugs or get rid of toxins.

Spindler's team fed three mice a normal diet for their whole lives, and fed another three on half-rations3. Three more mice were switched from the normal diet to half-feed3 for a month when they were 34 months old - equivalent to about 70 human years.

The researchers checked the activity of 11,000 genes from the mouse livers, and found that 46 changed with age in the normally fed mice. The changes were associated with things like inflammation and free radical production一 probably bad news for mouse health. In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes. But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 per cent of these gene changes.

"This is the first indication that these effects kick in pretty quickly," says Huber Warner from the National Institute on Aging near Washington D. C.

No one yet knows if calorie restriction works in people as it does in mice, but Spindler is hopeful. "There's attracting and tempting evidence out there that it will work," he says.

If it does work in people,there might be good reasons for rejuvenating the liver. As we get older, our bodies are less efficient at metabolizing drugs, for example. A brief period of time of dieting, says Spindler, could be enough to make sure a drug is effective.

But Spindler isn't sure the trade-off is worth it. "The mice get less disease, they live longer, but they're hungry," he says. "Even seeing what a diet does, it's still hard to go to a restaurant and say: 'I can only eat half of that,. "

Spindler hopes we soon won't need to diet at all. His company, Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.

詞匯：

meager adj.不足的

youthful adj.有青春活力的

vigor n.精力，活力

metabolize vt. 使（一種物質(zhì)）進(jìn)入新陳代謝過(guò)程

genetic adj.基因的

rejuvenation n.恢復(fù)活力，返老還童

注釋?zhuān)?/p>

1.hang on to ：繼續(xù)保留。例如：You should hang on to that painting 一 it might be worth a lot of money one day.你應(yīng)該繼續(xù)保留那幅畫(huà)-----或許有一天它會(huì)值很多錢(qián)。

2.The genetic rejuvenation won't reverse other damage caused by time for the mouse, but could help its liver metabolize drugs or get rid of toxins：老鼠的肝部基因恢復(fù)活力不會(huì)逆轉(zhuǎn)老鼠在其他方面的老化，但卻有助于肝臟代謝藥物或除去毒素。other damage caused by time歲月造成的莫他方面的破壞，即"其他方面的老化"。metabolize drugs：代謝藥物，即"使藥物參與新陳代謝以提高藥效"。get rid of：擺脫，除去。

3.half-ration和half-feed都是指"老鼠飼料正常定量（normal diet)的一半"。

4.free radical production:指體內(nèi)自由基的產(chǎn)生(形成）。

5.kick in：意為"開(kāi)始起作用"。 如：We're still waiting for the air conditioning to kick in.我們還在等著空調(diào)開(kāi)始起作用。

6.be worth it：意為"值得，有益"。如：They are expensive, but they are worth it.那些東西很貴，但劃得來(lái)。

練習(xí)：

1.According to the passage, which of the following is NOT true?

A Eating less than usual might make us live longer.

B If we go on a diet when old, we may keep healthy.

C Dieting might not be needed.

D We have to begin dieting since childhood.

2.Why does the author mention an elderly mouse in paragraph 2?

A To describe the influence of old age on mice.

B To illustrate the effect of meager food on mice.

C To tell us how mice's liver genes behave.

D To inform us of the process of metabolizing drugs.

3.What can be inferred about completely normally fed mice mentioned in the passage?

A They will not experience free radical production.

B They will experience more genetic rejuvenation in their lifetime.

C They have more old liver genes to behave like young genes.

D They are more likely to suffer from inflammation.

4.According to the author, which of the following most interested the researchers?

A The mice that started dieting in old age.

B 27 of those 46 old genes that continued to behave like young genes.

C Calorie restriction that works in people.

D Dieting that makes sure a drug is effective.

5.According to the last two paragraphs, Spindler believes that A calorie restriction is very important to young people.

B seeing the effect of a diet, people will like to eat less than normal.

C dieting is not a good method to give us health and long life.

D drugs do not have the effects of calorie restriction.

答案與題解：

1.D第一k第一句講"節(jié)食可能不是非做不可的事"，第二句講"即使上了年紀(jì)再節(jié)食，我們 仍然有可能在很大程度上保持青春活力"，因此，"我們必須從小就開(kāi)始節(jié)食"是錯(cuò)誤的，D是答案。

2.B第二段提及"一只髙齡老鼠"的時(shí)候，作者談到，"只要連續(xù)四周限制它進(jìn)食，它的肝臟基因就會(huì)變得和衰老前一樣充滿(mǎn)活力"。據(jù)此，"為了描述節(jié)食對(duì)老鼠所產(chǎn)生的影響"最好地回答了題干中的問(wèn)題o

3.D 第四段提到，"正常飼養(yǎng)的老鼠隨著年齡的增長(zhǎng)有46條肝臟基因會(huì)發(fā)生變化，這種變化與炎癥和有機(jī)體組織無(wú)限激增有關(guān)"，因此，D正確。

4.A第四段最后一個(gè)句子講"但最驚人的發(fā)現(xiàn)是那些上了年紀(jì)才開(kāi)始節(jié)食的老鼠也能從70%的基因變化中受益"。"最驚人的"自然是"最令研究人員感興趣的"。

5.C文章的最后兩段談及Spindler對(duì)節(jié)食的看法。首先，他不能肯定節(jié)食是否值得。.其次, 他希望在不久的將來(lái)，我們不必節(jié)食。所以我們可以推知，他認(rèn)為節(jié)食不是得以健康長(zhǎng)壽的好辦法。

參考譯文

第十六篇為生存而食

粗茶淡飯或許能給你健康和長(zhǎng)壽，但這并不有趣--很有可能也沒(méi)必要。即便在年老以后才 開(kāi)始節(jié)食我們也能在很大程度上保持住青春活力。

加州大學(xué)Riverside分校的斯蒂芬o斯潘德?tīng)柤捌渫掳l(fā)現(xiàn)，只要連續(xù)四周限制一些衰老的老 鼠進(jìn)食，它們的肝臟基因就會(huì)變得和衰老前一樣充滿(mǎn)活力。雖然老鼠的肝部基因恢復(fù)活力不會(huì)逆 轉(zhuǎn)它們?cè)谄渌矫娴睦匣?，但是卻有助于這些老鼠的肝臟對(duì)藥物的新陳代謝和清除毒素。

斯潘德?tīng)柕年?duì)員們一直給其中的三只老鼠正常量的飼料，而給另外三只老鼠正常量飼料的一半，給三只34個(gè)月大的老鼠（相當(dāng)于人類(lèi)年齡的70歲）喂了一個(gè)月的半量飼料，之前這三只老鼠 的飼料量是正常的。

研究者們檢查了這些老鼠肝臟的11,000種基因的活性，發(fā)現(xiàn)正常飼養(yǎng)的老鼠有46種基因隨 年齡的改變而改變。這些改變都與體內(nèi)自由基的產(chǎn)生有關(guān)--這對(duì)老鼠的健康來(lái)說(shuō)不是什么好消息。而對(duì)于那些終身都在節(jié)食的老鼠來(lái)說(shuō)，那46種基因中的27種仍然繼續(xù)保持著青春活力。但 是最令人吃驚的發(fā)現(xiàn)卻是那些只是在老年時(shí)期節(jié)食的老鼠們受益于70%的基因變異。

"這只是第一個(gè)這些效果迅速起作用的暗示"，來(lái)自華盛頓特區(qū)周邊的國(guó)家老年學(xué)學(xué)院的哈勃o華納說(shuō)。

至今仍然沒(méi)有人清楚卡路里的控制對(duì)人類(lèi)來(lái)說(shuō)是否如同對(duì)老鼠那樣有效，但是斯潘德?tīng)枌?duì)此 充滿(mǎn)了希望："有足以引人注意的證據(jù)表明這同樣有效。"

如果這確實(shí)也對(duì)人類(lèi)有效，我們有理由相信肝臟也可能恢復(fù)活力。舉個(gè)例子，隨著我們一天天衰老，我們的身體對(duì)藥物的新陳代謝越來(lái)越?jīng)]有效率。短時(shí)期內(nèi)的節(jié)食，斯潘德?tīng)栒f(shuō)到，完全足以保證藥效。

但是斯潘德?tīng)柌⒉淮_定這個(gè)方法值得嘗試。"老鼠患病少了，壽命延長(zhǎng)了，但是它們很饑餓，"他說(shuō)，"即使能清楚地認(rèn)識(shí)到節(jié)食的功效，人們?nèi)匀缓茈y在餐館中說(shuō)自己只能吃一半的食物。"

斯潘德?tīng)栂Ｍ覀兏揪筒挥霉?jié)食。他的公司，加利福尼亞州的壽命遺傳學(xué)公司，正在尋找有限制卡路里效能的藥物

編輯推薦：

2013年職稱(chēng)英語(yǔ)考試報(bào)名專(zhuān)題

2012年職稱(chēng)英語(yǔ)考試真題匯總

（責(zé)任編輯：vstara）

共2頁(yè),當(dāng)前第1頁(yè)  第一頁(yè)  前一頁(yè)  下一頁(yè)