2. 外语
  3. For years the media, food labels, dietitians, and even scientists who should know better have bombarded (轰炸) us with advice to l

For years the media, food labels, dietitians, and even scientists who should know better have bombarded (轰炸) us with advice to l

admin2012-01-27  23
问题     For years the media, food labels, dietitians, and even scientists who should know better have bombarded (轰炸) us with advice to load up on antioxidants: compounds found mostly in fruits and vegetables that mop up free radicals, which are highly reactive clusters of atoms that have been fingered as the evil-doers responsible for aging and for illnesses from cancer to heart disease.
    Not so fast. First, studies piled up showing that taking antioxidants — even such common and seemingly harmless ones as vitamins C and E — as supplements was not beneficial to health and might even be dangerous. Many of the free radicals that are neutralized by antioxidants perform valuable functions in the body. The most important: fighting toxins (毒素) and fighting cancer. Maybe it’s not such an excellent idea to flood the body with something that neutralizes these warriors of the immune system. Or as British chemist and science writer David Bradley noted in his blog, Reactive Reports, "It’s always struck me as odd that you would want to absorb extra antioxidants anyway, given that oxidizing agents are at the front-line of immune defense against pathogens(病原体) and cancer cells... Suffice to say that taking antioxidant supplements... may not necessarily be good for your health if you already have health problems, especially cancer or an infection."
    The first hints that the trend was crashing came from the hundreds of studies that have tried to assess the health effects of antioxidant supplements. The results have not been pretty. In 2008 the Cochrane Collaboration, an international organization of scientists who assess medical research, carefully checked 67 studies with nearly 400,000 participants. The goal: to determine whether antioxidant supplements reduce mortality in either healthy people or in people with diseases. Conclusion: "We found no evidence to support antioxidant supplements for primary or secondary prevention, and Vitamin A and E may increase mortality." In analyses of antioxidant supplements and Lou Gehrig’s disease, Alzheimer’s or mild cognitive impairment, and lung cancer, the Cochrane scientists’ verdict was the same: no. And each analysis had an alarming refrain about increasing overall mortality.
    It’s not clear why antioxidants in supplement form might be so dangerous. One idea holds that at high doses they become pro-oxidants, stimulating the harmful DNA- and cell-damaging reactions they’re supposed to prevent. But a more likely explanation is that we are seeing the human version of what scientists are finding in studies of lab animals: antioxidants interfere with immune-system cells that fight infection and cancer.
What do we learn about David Bradley?
选项 A、He is one of the scientists who "should know better".
B、He has made many experiments on antioxidants.
C、He is against taking extra antioxidants.
D、He is against taking extra vitamins.
答案C
解析 根据题干中的David Bradley将本题出处定位到第二段第六句。该句提到，正如英国化学家与科学作家David Bradley在他的博客中提到的：“我一直认为疯子才想摄取额外的抗氧化剂……补充抗氧化剂很可能不会给你的健康带来好处。”由此可见，他反对服用额外的抗氧化剂，故答案为[C]，同时排除[D]“他反对服用额外的维生素”。首段提到的scientists who should have know better指的是那些建议人们摄入抗氧化剂的科学家，而。David是反对摄入过多抗氧化剂的，所以他不属于上述科学家之列，故排除[A]。文中未提到David Bradley是否就抗氧化剂做实验的问题，故排除[B]。
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