你究竟应该睡多久？.doc

你究竟应该睡多久？ Experts generally recommend seven to nine hours a night for healthy adults. Sleep scientists say new guidelines are needed to take into account an abundance of recent research in the field and to reflect that Americans are on average sleeping less than they did in the past.专家的建议是，成人最好一晚上睡7到9个小时。睡眠科学家说考虑到睡眠领域的众多研究都反映现在美国人的平均实际睡眠时间低于过去，有必要制定新的准则。 Several sleep studies have found that seven hours is the optimal amount of sleep—not eight, as was long believed—when it comes to certain cognitive and health markers, although many doctors question that conclusion.不少睡眠研究都表明7个小时是最佳的睡眠时间(当考虑到一定的认知和健康标志的时候)——而不是之前一直认为的8个小时，而很多医生都质疑这一结果。 Other recent research has shown that skimping on a full nights sleep, even by 20 minutes, impairs performance and memory the next day. And getting too much sleep—not just too little of it—is associated with health problems including diabetes, obesity and cardiovascular disease and with higher rates of death, studies show.有相关研究表明熬夜，即使你只少睡了20分钟，也会损害第二天的表现和记忆。而睡得太多也与诸如糖尿病、肥胖症、冠心病这些病联系在一起，死亡率也会更高。 The lowest mortality and morbidity is with seven hours, said Shawn Youngstedt, a professor in the College of Nursing and Health Innovation at Arizona State University Phoenix. Eight hours or more has consistently been shown to be hazardous, says Dr. Youngstedt, who researches the effects of oversleeping.美国亚利桑那州立大学护理与健康创新学院的教授 Shawn Youngstedt，在研究过度睡眠的影响时说道：“睡7个小时的人，死亡率和发病率都是最低的。而睡8个小时及以上的人则比较危险。” The Centers for Disease Control and Prevention is helping to fund a panel of medical specialists and researchers to review the scientific literature on sleep and develop new recommendations, probably by 2015.疾病预防和控制中心正准备赞助一组医学专家和研究人员，让他们回顾以前关于睡眠的科学文献资料，他们可能于2015年推出新的睡眠准则。 Daniel F. Kripke, an emeritus professor of psychiatry at the University of California San Diego, tracked over a six-year period data on 1.1 million people who participated in a large cancer study. People who reported they slept 6.5 to 7.4 hours had a lower mortality rate than those