托福閱讀材料之肥胖的人更易患癡呆

　　最新一項研究顯示，肥胖會加速人的認知能力衰退，從而增加患癡呆癥的風險。這項研究對6000多名年齡在35到55歲的英國公務員進行了為期十年的跟蹤調(diào)查，并且在十年期間對他們進行了三次記憶力和認知技能測試。結(jié)果顯示，身體肥胖且伴有不健康代謝變化的被試者認知技能退化速度比其他人要快。不過，專家強調(diào)，該研究關(guān)注的知識被試人群的認知功能，而不是癡呆癥。正常老化、輕微認知障礙以及癡呆癥之間的界限很模糊，但并不是所有的認知障礙都會導致癡呆癥。研究人員表示，目前還不清楚為何肥胖和代謝異常與大腦功能退化相關(guān)，不過懷疑可能與高血糖及高膽固醇等因素有關(guān)。

　　Being overweight is not just bad for waistlines but for brains too, say researchers who have linked obesity to declining mental performance.

　　Being overweight is not just bad for waistlines but for brains too, say researchers who have linked obesity to declining mental performance.

　　Experts are not sure why this might be, but say metabolic changes such as high blood sugar and raised cholesterol are likely to be involved.

　　Obesity has already been tipped as a risk factor for dementia.

　　The work, published in Neurology, tracked the health of more than 6,000 British people over a decade.

　　The participants, who were aged between 35 and 55, took tests on memory and other cognitive skills three times over a 10-year period.

　　People who were both obese and who had unhealthy metabolic changes showed a much faster decline on their cognitive test scores compared to others in the study.

　　Delving deeper

　　The experts stress that they only looked at cognitive function, not dementia.

　　The boundary between normal aging, mild cognitive impairment and dementia is blurred - not all impairment leads to dementia.

　　All of the study participants came from one group of civil service workers, which may mean the findings may not apply more generally to other populations.

　　They said: "More research is needed to look at the effects of genetic factors and also to take into account how long people have been obese and how long they have had these metabolic risk factors and also to look at cognitive test scores spanning adulthood to give us a better understanding of the link between obesity and cognitive function, such as thinking, reasoning and memory."

　　Shirley Cramer of the Alzheimer's Research UK said: "We do not yet know why obesity and metabolic abnormality are linked to poorer brain performance, but with obesity levels on the rise, it will be important to delve a little deeper into this association.

　　"While the study itself focuses on cognitive decline, previous research suggests that a healthy diet, regular exercise, not smoking and controlling blood pressure and cholesterol in midlife can also help stave off dementia. With dementia figures spiralling towards a million, the findings suggest we should be conscious of our general health throughout life."