TEXT THREE

Everyone is interested in whether different foods or nutrients affect our odds of getting diseases like cancer or of developing risk factors for those diseases, such as too much weight or high blood pressure. But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest. It’s also why you can be forgiven for often feeling whipsawed by headlines: Is coffee good or bad? What about alcohol, garlic, or chocolate?

This week researchers reported in the Journal of the American Medical Association that breast cancer survivors who cram their diets with fruits and vegetables are no more likely to escape a recurrence than women who stick to the usual five-a-day recommendation. Does that mean fruits and vegetables don’t protect against cancer? No—just that in this specific group of women with breast cancer, the extra greens and additional apples didn’t seem to help.

We asked researchers to explain why studies involving dietary changes are so hard to do—and what consumers should keep in mind when they read about them. Here’s what the experts said:

Most diet studies take place in the real world. That means study subjects are keeping diaries of what they eat as they go rather than having their intake strictly controlled by someone else. You can give them meal advice, counseling, and how-to books up to their ears, but at the end of the day, they are on their own when it comes to what they put in their mouths. It’s easier to get people to add something—like garlic, in the form of tasty sandwich spreads, or dark chocolate—than to take something away; no wonder a recent study comparing low-fat and low-carb diet plans found that almost no one was sticking to them by the end.

In studies focusing on diet, including the recent study on breast cancer recurrence, the amount of calories subjects reported eating would have caused them to lose far more weight than they actually did lose. The misreporting isn’t necessarily vicious, but the inaccuracies add up. Say you’re phoned about your daily intake on a day when it was someone’s birthday at work and you had a slice of cake. You may not report it, thinking that a typical day wouldn’t include the cake...forgetting yesterday’s "special occasion" piece of pizza, and the Big Gulp of the day before. Or, despite the portion size guides you get, you characterize your bagel from the deli as a 4-ounce standard serving when a 4-ounce bagel hasn’t been sighted in any major city for a decade.

"You can’t put a camera in everyone’s belly and see exactly what they ate," says Christopher Gardner, a nutrition scientist at the Stanford Prevention Research Center who has recently published research on garlic and diet plans. You can get around this in some studies by taking objective measurements. Weight, for example, or if you’re assessing intake of fruits and veggies, you can measure the level of pigments called carotenoids in the blood. In the breast cancer study, blood tests showed that the study subjects actually did eat more fruits and veggies (carotenoid concentration was 73 percent higher in those women after one year and 43 percent higher after four years). But objective measures can’t definitively nail down whether someone is eating nutrients in certain proportions.

1. One can be forgiven for feeling whipsawed by feeling whipsawed by those headlines because_____

[A] there is no solid and convincing scientific hypothesis on these subjects.

[B] they question about what the healthiest food is has no answers.

[C] opinions on these subjects are quite contradictory.

[D] there is no authoritative answer to these questions.

2.Which one of the following statements is TURE of the conclusion of the study on breast cancer recurrence ?

[A] Women who stick to the five-a-day recommendation are less likely to have a recurrence.

[B] Women who eat extra greens and vegetables are less likely to escape a recurrence.

[C] Women could not depend on fruit diet to avoid the breast cancer recurrence.

[D] Fruits and vegetables are no good to women with breast cancer.

3.From the results of the studies focusing on diet, it can be inferred that_____

[A] the amount of calories set in diet could not help people to lose weight.

[B] people are reluctant to take part in such studies.

[C] it is difficult to get valuable conclusion from these studies.

[D] this kind of studies is not objective enough.

4.The fact that a 4-ounce bagel hasn’t been sighted in any major city for a decade implies that _____

[A] you should re-examine the standard size of the food you intake.

[B] you tend to give an inaccurate report of your actual diet.

[C] you fail to cooperate with the doctor by false record of your daily food.

[D] you make a mistake in noting down the size of standard serving.

5.The limitation of the objective measurements mentioned in the last paragraph is that _____

[A] they could only assess the proportion of fruits and veggies study subjects have taken.

[B] they could not have the subjects follow exactly the food proportion of their diet.

[C] they could not identify the levels of all the nutrients in patients’ blood.

[D] they could not tell the exact proportions of nutrients study subjects have eaten.

篇章剖析：

这篇文章讲述了关于饮食的一些研究所存在的问题。第一段讲述了人们对于食物和营养的困惑;第二段讲述研究表明蔬菜和水果对于防止癌症复发没有改善作用;第三、四段讲述专家对这些问题的解释;第五段讲述饮食研究中存在的一些人们没有进行客观报告的问题;第六段讲述更加客观的测量方法。

词汇注释：

whipsaw v. 拉锯 calorie n. 卡路里

bagel n. 百吉饼 deli n. 熟食店

pigment n. 色素 carotenoid n. 类胡萝卜素

难句突破：

(1) But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest.

[主体句式] But there are many barriers …, which is why…

[结构分析] 这是一个复合句，which引导的定语从句用来修饰整个主句;定语从句中，why引导的是表语从句，该从句中what引导的是宾语从句。

[句子译文] 但是要进行饮食变化的调查有太多的障碍，这就是我们为什么不能轻松地告诉人们什么食物是最健康的。

(2) You can give them meal advice, counseling, and how-to books up to their ears, but at the end of the day, they are on their own when it comes to what they put in their mouths.

[主体句式] You can give them…, but …

[结构分析] 这是一个并列句，后面分句中when引导的是时间状语从句。

[句子译文] 你可以告诉他们一些用餐建议，告诉他们应该买些什么，但是这一天里，他们究竟往自己嘴里塞些什么东西就是由不得别人了。

1. One can be forgiven for feeling whipsawed by those headlines because_____ 1. 人们看到那些新闻标题会觉得很迷茫，这很可以理解，因为_____

[A] there is no solid and convincing scientific hypothesis on these subjects. [A] 关于这些主题的研究还没有得出可靠和可信的假设。

[B] the question about what the healthiest food is has no answers. [B] 关于什么食物是最健康的这个话题是没有答案的。

[C] opinions on these subjects are quite contradictory. [C] 关于这些话题的观点分歧很大。

[D] there is no authoritative answer to these questions. [D] 这些问题不存在权威的答案。

[答案] D

[难度系数] ☆☆☆

[分析] 推理题。根据第一段“But there are many barriers to studying dietary change, which is why we still have no easy answers to the question of what, exactly, we should eat to be at our healthiest”，因为要进行摄入食物变化调查的障碍很多，因此在该问题上并没有一定的答案，选项中D最为符合题意。

2.Which one of the following statements is TURE of the conclusion of the study on breast cancer recurrence ? 2.关于乳癌复发的研究得出的结论，下列哪项陈述是正确的?

[A] Women who stick to the five-a-day recommendation are less likely to have a recurrence. [A] 坚持一天五顿饭的妇女的复发几率要小一些。

[B] Women who eat extra greens and vegetables are less likely to escape a recurrence. [B] 多吃绿色蔬菜和水果的妇女并不能躲避过复发。

[C] Women could not depend on fruit diet to avoid the breast cancer recurrence. [C] 妇女可以依靠水果餐来避免乳癌复发。

[D] Fruits and vegetables are no good to women with breast cancer. [D] 水果和蔬菜对于有乳癌的妇女没有好处。

[答案] B

[难度系数] ☆

[分析] 细节题。根据第二段“breast cancer survivors who cram their diets with fruits and vegetables are no more likely to escape a recurrence than women who stick to the usual five-a-day recommendation”，该研究报道表明吃大量的蔬菜、水果并不能让患有乳癌的妇女避免复发，那么B选项是正确的。D选项，虽然蔬菜、水果不能帮助妇女避免癌症复发，但是还是对她们身体有好处的。

3.From the results of the studies focusing on diet, it can be inferred that_____ 3.从饮食研究的结果来看，可以推出_____

[A] the amount of calories set in diet could not help people to lose weight. [A] 食物中的卡路里数量并不能帮助人们减肥。

[B] people are reluctant to take part in such studies. [B] 人们不愿意参加这样的研究。

[C] it is difficult to get valuable conclusion from these studies. [C] 要从这些研究中得到有价值的结论很难。

[D] this kind of studies is not objective enough. [D] 这类的研究不够客观。

[答案] D

[难度系数] ☆☆☆

[分析] 推理题。根据第五段“the amount of calories subjects reported eating would have caused them to lose far more weight than they actually did lose”，这种研究的结果表明，受实验者报告自己摄入的卡路里数量本来可以让他们体重降的幅度更大的，这和他们自己报告的情况不够切实有关。因此，这样的研究不够客观。答案为D选项。

4.The fact that a 4-ounce bagel hasn’t been sighted in any major city for a decade implies that _____ 4.已经有十几年在任何一个大城市都没有出售这种4盎司的百吉饼了，这个事实说明了_____

[A] you should re-examine the standard size of the food you intake. [A] 你应该重新检查你摄入食物的标准量。

[B] you tend to give an inaccurate report of your actual diet. [B] 你更容易给出与你实际饮食情况相左的报告。

[C] you fail to cooperate with the doctor by false record of your daily food. [C] 你错误地报告了自己每日的饮食，不能和医生很好地合作。

[D] you make a mistake in noting down the size of standard serving. [D] 在记录标准尺寸时犯了一个错误。

[答案] B

[难度系数] ☆☆☆

[分析] 推理题。根据第六段“Or, despite the portion size guides you get, you characterize your bagel from the deli as a 4-ounce standard serving when a 4-ounce bagel hasn’t been sighted in any major city for a decade”，尽管吃了许多百吉饼，却报告说只吃了4盎司大的，那么可以看出报告有误。答案为D选项。C选项错误的原因在于尽管报告有误，但是没有说明这就是不与医生合作。

5.The limitation of the objective measurements mentioned in the last paragraph is that _____ 5.最后一段中提到的客观度量的局限性在于_____

[A] they could only assess the proportion of fruits and veggies study subjects have taken. [A] 它们只能估量被研究者的水果和蔬菜摄入量。

[B] they could not have the subjects follow exactly the food proportion of their diet. [B] 被研究者无法严格遵循这些度量规定的食物比例。

[C] they could not identify the levels of all the nutrients in patients’ blood. [C] 它们分辨不了被研究者血液中所有营养物质的水平。

[D] they could not tell the proportions of nutrients study subjects have eaten. [D] 它们提供不了被研究者已摄入营养品的数量。

[答案] D

[难度系数] ☆☆☆☆

[分析] 细节题。根据最后一段“In the breast cancer study, blood tests showed that the study subjects actually did eat more fruits and veggies (carotenoid concentration was 73 percent higher in those women after one year and 43 percent higher after four years). But objective measures can’t definitively nail down whether someone is eating nutrients in certain proportions”，这种血液测量可以测出试验者具体摄入的食物和蔬菜的量，但是却不能确定人们是否摄入了一定量的营养品。答案为D选项。

参考译文：

人们都很想知道到底不同的食物或营养物质是否会影响到我们患癌症等疾病的几率，或引发导致这些疾病的危险因子，如肥胖或高血压。但是要进行饮食变化的调查有太多的障碍，这就是我们为什么不能轻松地告诉人们什么食物是最健康的。这也就是为什么当人们经常被报纸头条弄得一头雾水：咖啡有利于还是有害健康?酒类、大蒜和巧克力呢?

本周《美国医学协会期刊》上的一篇报道称患乳癌而后康复的女性中，每天吃大量蔬菜、水果的人并不比坚持接受每天五顿饭建议的人们更可能避免复发。那么这是不是就意味着蔬菜、水果不能抗癌呢?是的，对患有乳癌的女性来说，额外的绿色蔬菜和苹果无济于事。

我们会问研究者为什么食物变化的研究这么难做呢，人们应该怎样对待媒体上的各种评价?专家是这样回答的：

大多数的食物研究是在现实生活中进行的，这就意味着研究主体只是每天记录下自己吃的食物，而不是由别的人严格控制他们的饮食。你可以告诉他们一些用餐建议，告诉他们应该买些什么，但是这一天里，他们究竟往自己嘴里塞些什么东西就是由不得别人了。让人们往食物里加上点什么——如夹在美味的三明治里面的大蒜，或是黑巧克力——要比让他们把这些食物拿开容易得多。最近的一项比较低脂和低碳食物的研究表明，到最后几乎没有人坚持这种食谱。

关于饮食的研究，包括最近关于乳癌复发的研究中，按照实验被试报告的卡路里摄入量，这本可以使他们体重下降更大的幅度。这种误报不一定是恶意的，但是确实有各种不精确因素。比如你某天打电话汇报自己吃的东西，而那天正好是一个人的生日，而你吃了一片蛋糕。但你可能不会提到这片蛋糕，觉得正常情况下你是不会吃蛋糕的，同样你忘记了昨天吃过“特殊节日”的比萨，前天吃了Big Gulp。或者是尽管你吃了很多，但你却说自己从熟食店买的百吉饼只有4盎司大，而实际上这十几年以来已经没有任何一个大城市还在出售4盎司的百吉饼了。

“你不可能在每个人的肚子里都安装一个摄像机，看看他们到底吃了什么。”斯坦福预防研究中心营养师Christopher Gardner说，他刚刚发表了关于大蒜和饮食计划的研究。在一些研究中你可以采用客观的测量法来避免以上情况发生。比如，如果在检测人们蔬菜和水果摄入量时，可以测量人们血液中叫做类胡萝卜素的色素水平。乳癌研究中，血液测量表明受试者确实吃了更多的食物和蔬菜(一年后类胡萝卜素浓度高了73%，四年后高了43%)。但是客观的方法不能确定人们是否摄入了一定比例 的营养品。