問題詳情

第 72 至 75 題為題組    People diet for many reasons - to fit into clothes, to look more attractive, or for the sakeof their health. But to improve their memory? It's an interesting idea, and one that's been givenfresh support by Veronica Witte from the University of Munster in Germany.   Witte found that elderly people who slash the calories in their diet by 30% were betterable to remember lists of words than people who stuck to their normal routine. It's the firstexperiment to show that cutting calories can improve human memory at an age when decliningmemory is par for the course.    The benefits of low-calorie diets have been extensively studied in animals, ever sinceClive McCay discovered that "caloric restriction" doubled the lifespan of rats, over 70 yearsago. But until now, no experiments had confirmed that the same benefits are relevant to thehuman brain.    Witte did so by recruiting fifty healthy people, aged 52-68, and asking twenty of them tocut their calorie intake by 30%. Experienced dieticians gave them advice on following theirnew diet and were just a phone call away for the duration of the experiment. A second groupof 20 volunteers were asked to eat more unsaturated fatty acids, such as olive and fish oils. The10 remaining volunteers carried on with business as usual.   At the start, middle and end of the period, Witte took blood samples from the volunteers.She also tested their memories by asking them to learn a list of 15 words and repeat as many asthey could after half an hour. Witte found that the low-calorie group remembered more wordsand made fewer mistakes at the end of the three months of the experiment.   Witte argues that it was the drop in calories that lay behind these changes. Of course, it'spossible that the low-calorie group were actually benefiting from the interaction they had withthe dieticians, rather than anything to do with their diets. However, Witte thinks that thisexplanation is a very unlikely one, for the volunteers who ate more unsaturated fatty acids alsohad friendly dieticians to talk to, and their memories did not get better   So what was behind their superior recollection? Their blood samples provide a clue:after the three months, the volunteers had lower levels of the hormone insulin circulatingaround their bodies. In fact, those who showed the greatest improvements in memory also hadthe largest falls in insulin - a link that was particularly found in those who stuck most closelyto their dietary instructions.    For the moment, Witte's work suggests a promising and relatively simple way ofimproving memory in old age. It will, of course, be important to repeat the experiment with amuch larger number of people. And it will be interesting to see whether a low-calorie diet hasany other mental benefits, beyond the ability to commit words to memory.
72. What is the best title of this passage?
(A) The Benefits of Low-calorie Diet
(B) A Study on Memory Loss from a German University
(C) How to Improve Your Memory
(D) Low-calorie Diets Improve Memory in Old Age

參考答案

答案：D
難度：非常困難0
統計：A(0),B(0),C(0),D(0),E(0)

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