南加州医科大学的一个研究团队发现血浆胆固醇水平与阿尔茨海默病之间有更深层的联系，他们的研究结果与此前的研究结果相近，即在炎症过程中高胆固醇可能是该病的一个重要诱因，该结果在亚特兰大举行的神经科学学会的年会上报告。
他们的研究工作验证了这一假设：即不管是饮食引起的或者遗传因素造成的高胆固醇都会加剧大脑的炎症反应，并刺激淀粉样蛋白的产生，逐步引起神经退行性病变并出现阿尔茨海默病的痴呆特征。
此前的一项在小鼠中进行的实验是用高胆固醇、高脂饲料喂养小鼠两个月，然后进行一项记忆任务测试，结果接受高胆固醇、高脂的动物出现记忆能力消退并伴有显著的神经炎症反应。其它的平行研究尽管对食物配方进行了调整，但凡是高胆固醇水平的动物仍然出现相近的症状。
上述试验结果都为目前的假设提供了证据，即体内食物来源的或遗传因素所致的高胆固醇是引发伴随阿尔茨海默病发病出现的认知能力下降的诱因。这些结果还相应的为低脂饮食或者说富含多聚不饱和脂肪酸的饮食可以预防阿尔茨海默病的发生铺平了道路。而且研究所观察到的这种食物中高胆固醇所致的神经炎症变化与记忆力减退还提示我们，抗炎治疗可能对阿尔茨海默病的痴呆病征有效。
脑中胆固醇水平升高会诱发一个类似于我们在心血管疾病及动脉粥样硬化中所观察到的级联效应。炎症会脑部中小血管产生不利影响，使之过滤有害物质的能力下降，继而炎症反应所引起的免疫细胞在该部位聚***，通过一系列反应逐渐形成淀粉样蛋白，最终导致突触传递紊乱，认知能力下降而出现类似痴呆症状。
http://www.medicalnewstoday.com/medicalnews.php?newsid=54367
Link Between High Cholesterol And Alzheimer's Discovered By MUSC Researchers
A team of scientists at the Medical University of South Carolina (MUSC) has found evidence that further links high cholesterol levels to Alzheimer's disease. The research, led by MUSC neuroloscientist, Narayan R. Bhat, Ph.D., further supports similar previous research as well as high cholesterol's role in inflammation which may trigger the disease. The findings were recently presented at the Society for Neuroscience annual meeting in Atlanta.
Bhat and his team of MUSC Neuroscientists tested their hypothesis that high cholesterol, resulting from either diet or genetic disposition, would intensify the brain's inflammatory response and spur amyloid generation that would, in turn, lead to the neurodegeneration and dementia characteristic of Alzheimer's disease.
A preliminary study of mice that were fed a high cholesterol, high fat diet for two months, and then tested on a memory task, showed a loss of working memory in association with a significant neuroinflammatory response. Parallel studies of mice with existing elevated cholesterol levels revealed similar signs of memory loss and neuroinflammatory responses regardless of the type of diet they were on.
These findings provide experimental evidence for the current idea that high cholesterol levels in the body resulting from dietary and/or genetic factors may contribute to the onset of cognitive decline associated with Alzheimer's disease. These findings could potentially pave the way for low-fat diets or, potentially, diets high in polyunsaturated fats as a preventive measure against the risk of developing Alzheimer's disease. In addition, an observed connection between diet-induced neuroinflammatory changes and memory deficit emphasizes the potential therapeutic usefulness of anti-inflammatory treatments against Alzheimer's-like dementia.
It is likely that high cholesterol levels may result in an inflammatory cascade as has been observed in cardiovascular disease, atherosclerosis. Potentially, systemic inflammation may also adversely affect tiny blood vessels in the brain, making them less effective at filtering out harmful compounds. The gathering of immune cells at site of inflammation in the brain could then initiate a cascade of events leading to the build-up of amyloid in the brain and synaptic/cognitive dysfunction.
编辑：蓝色幻想
