The Search for the Anti·aging Pill成分分析.docVIP

READING PASSAGE 3 You should spend about 20 minutes on Questions 28—40, which are based on Reading Passage 3 The Search for the Anti-·aging Pill In government laboratories and elsewhere, scientists are seeking a drug able to prolong life and youthful vigor．Studies of caloric restriction are showing the way As researchers主 on aging noted谓 recently,（no treatment主 on the market today has been proved to谓 slow human aging-补）宾从the build-up of molecular and cellular damage that increases vulnerability to infirmity 定从as we grow older．But one intervention，consumption of a lowcalorie*yet nutritionally balanced diet主)．Works incredibly well in a broad range of animals，increasing longevity and prolonging good health)．Those findings主 suggest谓 (that caloric restriction could delay aging and increase longevity in humans,too宾从)． Unfortunately, for maximum benefit，people主 would probably have to reduce 谓their caloric intake宾 （by roughly thirty per cent，equivalent to dropping from 2,500 calories a day to l750．Few mortals 主could stick to 谓that harsh a regimen，especially for years on end． But what if someone主 could create谓 a pill宾 that 定从mimicked the physiological effects of eating less without actually forcing people to eat less?Could such a‘caloric-restriction mimetic’，as we call it，enable people 宾to stay healthy longer, postponing age-related disorders宾补(such as diabetes，arteriosclerosis，heart disease and cancer)until very late in ife? Scientists 主first posed 谓this question宾 in the mid-1990s．after引导时间状语从句 researchers came upon a chemical agent that in rodents seemed to reproduce many of caloric restrictions benefits．No compound主 that would safely achieve the same feat in people定从 has been found谓 yet，but the search has been informative and has fanned 谓hope宾 that caloric-restriction (CR) mimetics can indeed be developed eventually． The benefits of caloric restriction The hunt for CR mimetics主 grew out 谓of a desire to better understand caloric restrictions many effects on the body．S