VOA标准英语2010年-Blood Vessel Disease Linked to Dementi

Researchers have identified a link between dementia and the brain damage that can occur in older people with high blood pressure and other forms of cardiovascular disease. High blood pressure, high cholesterol², and other conditions that affect blood flow don't have obvious symptoms, which is why they are sometimes described as silent vascular¹ disease. But researcher Owen Carmichael at the University of California-Davis says most people develop vascular disease as they age, and it affects blood flow to the brain.
"Vascular disease is so widespread, and such a small amount of it can affect your ability to think, that it's almost — I don't want to use the word 'ubiquitous,' but it's very, very common in the elderly," he said.
Carmichael is lead author of a new study that found people with brain damage caused by this silent vascular disease are more likely to show a faster decline in memory and thinking ability — cognitive³ impairment.
Study participants were given MRI scans to identify damaged brain tissue that was, in effect, starved when the blood vessels⁴ couldn't provide enough nutrients⁵. They were also given tests to evaluate any change in their cognitive abilities over three years.
Although people with damage to the brain tissue called white matter are more likely to have dementia, Carmichael stops short of saying that the brain damage actually causes the dementia.
"Many different things are going on in the brains of people who are aging. So cognitive problems in late in life are not like cancer or HIV, where there's basically one big biological problem going on. There's actually many different things going on at the same time."And he says it's up to researchers to figure out how those factors interact to cause the decline in memory, thinking, and other skills that are seen in dementia.
"If you walked in on day one and you seemed to have a great deal of this white matter damage, then you tended to do worse over the course of a year in terms of your ability to think," he said. Carmichael says for now this is just a research finding, not the basis for screening patients to see if they have a higher chance of developing dementia. But he says it does underscore the importance of cardiovascular health for keeping the brain, as well as the heart, healthy.
He says there's no treatment for Alzheimer's Disease, one feared cause of dementia.
"But now, if vascular problems are also affecting your ability to think over time, we have gobs of treatments for that. There are all sorts of different things you can do to help your blood flow. So treating the vascular disease might actually, in the long term, help your process of cognitive aging."Owen Carmichael describes the results of this study in the Archives of Neurology, a journal published by the American Medical Association.

1 vascular   

adj.血管的，脉管的

参考例句：

• The mechanism of this anomalous vascular response is unknown.此种不规则的血管反应的机制尚不清楚。
• The vascular changes interfere with diffusion of nutrients from plasma into adjacent perivascular tissue and cells.这些血管变化干扰了营养物质从血浆中向血管周围邻接的组织和细胞扩散。

2 cholesterol   

n.（U）胆固醇

参考例句：

• There is cholesterol in the cell of body.人体细胞里有胆固醇。
• They are determining the serum-protein and cholesterol levels.他们正在测定血清蛋白和胆固醇的浓度。

3 cognitive   

adj.认知的，认识的，有感知的

参考例句：

• As children grow older,their cognitive processes become sharper.孩子们越长越大，他们的认知过程变得更为敏锐。
• The cognitive psychologist is like the tinker who wants to know how a clock works.认知心理学者倒很像一个需要通晓钟表如何运转的钟表修理匠。

4 vessels   

n.血管( vessel的名词复数 )；船；容器；（具有特殊品质或接受特殊品质的）人

参考例句：

• The river is navigable by vessels of up to 90 tons. 90 吨以下的船只可以从这条河通过。 来自《简明英汉词典》
• All modern vessels of any size are fitted with radar installations. 所有现代化船只都有雷达装置。 来自《现代汉英综合大词典》

5 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》