求翻译短文 According to a report issued in May 1998,elderly peopl

求翻译短文 According to a report issued in May 1998,elderly people who have .不要机器译的

高度的压力会损害记忆力
根据1998年发表的一份报告,如果老年人在血液中的皮质醇含量持续处于高水平,他们的记忆力不及那些同龄但紧张激素水平较低的人.更重要的是,皮质醇水平高也与海马区萎缩有关,那就是在学习和记忆方面发挥关键作用的大脑区域.
研究结果表明,即使皮质醇水平在正常"健康"的范围内,实际上可以加速大脑老化.
研究结果是「现在提供了大量的证据,表明如肾上腺压力荷尔蒙长期处于高的分泌状态下,可促使正常的老年人的海马区老化」,这是出自列克星敦肯塔基大学（University of Kentucky at Lexington）的波特（Nada Porter）教授和兰菲尔德（Philip Landfield）教授的发表.肾上腺在肾脏上方,皮质醇是一种激素,由肾上腺因应压力而释放.
在5至6年间,鲁皮恩（Sonia Lupien）博士和她的同事为51名健康的志愿者量度他们在24小时内的皮质醇水平,大部分志愿者都是70来岁的.
尽管皮质醇水平差异很大,随着时间的推移,参与者的测试结果可分为三小组：1.皮质醇逐渐增加,而目前状态是高（增加/高）；2.皮质醇逐渐增加,而目前状态是中度（增加/中度）; 3.皮质醇下降,而目前状态是中度（减少/中度）.
研究人员从“增加/高”组的志愿者中选了六个人,从“减少/中度”组中选了五个人,来测试他们的记忆力.在即时记忆测试中,两组差异不大,但与“减少/中度”组相比,“增加/高”组就存在了其它问题.
研究人员还发现,那些在“增加/高”组的海马区总体积,比那些在“减少/温和”组低14％,尽管其他脑区无明显差异.
结果表明,「.脑的老化是由于肾上腺皮质激素的水平增加而导致,一般不以为这是病理性的,而在正常范围的变化与大脑老化的速度变化相关」,波特教授及兰菲尔德教授的发表中说道,「这进一步表明,慢性压力可能会加速海马区的退化.」
High Stress May Damage Memory
According to a report issued in May 1998,elderly people who have consistently high blood levels of cortisol don't score as well on memory tests as their peers with lower levels of the stress hormone.What's more,high levels of cortisol are also associated with shrinking of the hippocampus,a region of the brain that plays a key role in learning and memory.
The findings suggest that even cortisol levels in the normal,"healthy" range can actually accelerate brain aging.
The study results "now provide substantial evidence that long-term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans," write Nada Porter and Philip Landfield of the University of Kentucky in Lexington in their editorial.Cortisol is a hormone released in response to stress by the adrenal glands,which sit on top of the kidneys.
Over a 5-to-6-year period,Dr.Sonia Lupien and his colleagues measured 24-hour cortisol levels in 51 healthy volunteers,most of whom were in their 70s.
Despite wide variation in cortisol levels,the participants could be divided into three subgroups:those whose cortisol progressively increased over time and was currently high (increasing/high); those whose cortisol progressively increased over time and was currently moderate (increasing/moderate); and subjects whose cortisol decreased,but was currently moderate (decreasing/moderate).
The researchers tested the volunteers' memory on six people in the increasing/high category and five people in the decreasing/moderate group.The groups did not differ on tests of immediate memory,but the increasing/high cortisol group had other memory problems compared with those in the decreasing/moderate group.
The researchers also found that the total volume of the hippocampus in those in the increasing/high group was 14% lower than those in the decreasing/moderate group,although there were no differences in other brain regions.
The results suggest that "…… brain aging can be accelerated by levels of adrental hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging," write Porter and Landfield."This further suggests that chronic stress may accelerate the worsening of hippocampus." 再答： 全手人翻译，欢迎采纳