文章大意:这是一篇说明文。一项针对老年痴呆症的重大研究表明,中年时每晚经常睡6小时或更少的人比那些每天睡7小时的人更容易患痴呆症。文章介绍了研究开展的过程以及研究人员对此的看法和建议。
People who regularly sleep for six hours or less each night in middle age are more likely to develop dementia than those who routinely manage seven hours, according to a major study into the disease.
Researchers found a 30% greater risk of dementia in those who during their 50s, 60s and 70s consistently had a short night's sleep, regardless of other risk factors such as heart condition and poor mental health.
Sabia, an author of the study at the university of Paris and her colleagues analyzed survey data from University College London's Whitehall study, which launched in 1985 and followed the health and lifestyles of more than 10,000 British volunteers. The French team focused on nearly 8,000 participants who self-reported their sleep patterns.
During 25 years of follow-up. 521 participants developed dementia, with most diagnosed in their late 70s. Writing in Nature Communications, the scientists described how those who routinely got six hours of sleep or less each night in their 50s and 60s were 30% more likely to develop dementia than those who typically managed seven hours.
The study does not prove that sleeping too little causes dementia, since sleep loss itself may be one of the earliest symptoms of the disease. But some scientists believe the results strengthen evidence that continuous poor sleep may at least contribute to the disease.
The first pathological changes that lead to dementia occur one to two decades before the disease becomes obvious, as sticky proteins called amyloid build up in the brain. When the 1985 Whitehall study first assessed the sleep of volunteers who later developed dementia, this process had probably not started. This meant that if they were sleeping too little, it was unlikely to have been caused by dementia-related brain changes.
“It strengthens the evidence that poor sleep in middle age could cause or worsen dementia in later life,” said Dr. Liz Coulthard, a consultant senior lecturer in dementia neurology. “It makes sense to take measures to improve sleep such as going outside during daylight hours to help maintain the natural rhythms that promote good sleep, avoiding too much alcohol or caffeine, particularly before bed, and finding a bedtime routine that works for you.”
8. What risk factor for dementia does the passage focus on?
A.Sleep loss. | B.Age. | C.Poor mental health. | D.Heart condition. |
9. How did French scientists get the research findings?
A.By making a comparison. | B.By monitoring sleep patterns. |
C.By interviewing British volunteers. | D.By analyzing previous survey data. |
10. In what tone do the scientists talk about the research?
A.Casual. | B.Doubtful. | C.Negative. | D.Cautious. |
11. What is the purpose of the last paragraph?
A.To give examples. | B.To collect proofs. |
C.To offer suggestions. | D.To present arguments. |