The Problem of Cholesterol
Cholesterol is essential for life. It is a component of cell membranes in mammals and is necessary for proper membrane function. Transported in the blood of all animals, cholesterol can come from the diet, can be recycled within the body through reabsorption, or produced "from scratch" by all cells. Cholesterol comprises about 25 percent of the brain's mass and, in addition to being part of the cell membranes, it is a key component of myelin. However, too much cholesterol in the blood increases the risk of vascular disease. High blood cholesterol can lead to the buildup of plaques in the walls of blood vessels, restricting and possibly blocking the flow of blood; this condition is called atherosclerosis.
The association between high blood cholesterol and Alzheimer's disease is under intense investigation. One hypothesis is that the cholesterol-filled plaques in blood vessels contribute to Alzheimer's disease by restricting blood flow to the brain, damaging but not killing neurons. Scientists also speculate that cholesterol may be involved in the metabolism of beta-amyloid, though this process is not yet fully understood. Studies in animals have found that a high-cholesterol diet can increase beta-amyloid deposits in the hippocampus. Other animal studies show that when AD transgenic mice are given a statin (a cholesterol-lowering drug), both their blood cholesterol and their beta-amyloid levels decrease. Recent large clinical trials examining the effectiveness of statins in slowing the progression of AD in patients with mild to moderate AD did not show an effect. However, there are a number of clinical trials now examining whether earlier treatment with statins might delay the onset of AD in individuals with MCI or at risk for AD.
Excerpted from THE ALZHEIMER'S PROJECT: MOMENTUM IN SCIENCE, published by Public Affairs, www.publicaffairsbooks.com.
In This Section
- Vascular Disease
- Insulin Resistance and Diabetes
- Connecting Alzheimer's Disease to Vascular Disease
- Vascular Injury
- Vascular Dementia and Alzheimer's Disease
- The Problem of Cholesterol
- What's Good for the Heart is Good for the Brain
- Atherosclerosis and Alzheimer's Disease
- Associating Alzheimer's Disease with Insulin Resistance and Diabetes
- Diabetes and Insulin Resistance
- Insulin in the Brain
Momentum in Science: The Supplementary Series
- Understanding and Attacking Alzheimer's 12 min
- How Far We Have Come in Alzheimer's Research 15 min
- Identifying Mild Cognitive Impairment 20 min
- The Role of Genetics in Alzheimer's 12 min
- Advances in Brain Imaging 11 min
- Looking Into the Future of Alzheimer's 6 min
- The Connection Between Insulin and Alzheimer's 21 min
- Inflammation, the Immune System, and Alzheimer's 29 min
- The Benefit of Diet and Exercise in Alzheimer's 16 min
- Cognitive Reserve: What the Religious Orders Study is Revealing about Alzheimer's 20 min
- Searching for an Alzheimer's Cure: The Story of Flurizan 30 min
- The Pulse of Drug Development 15 min
- The DeMoe Family: Early-Onset Alzheimer's Genetics 25 min
- The Nanney/Felts Family: Late-Onset Alzheimer's Genetics 20 min
- The Quest for Biomarkers 17 min
Video: Inside the Brain: Unraveling the Mystery of Alzheimer's Disease
This 4-minute captioned video shows the progression of Alzheimer's disease in the brain.
Inside the Brain: An Interactive Tour
The Brain Tour explains how the brain works and how Alzheimer's affects it.
Alzheimer's Disease: Unraveling the Mystery
This book explains what AD is, describes the main areas in which researchers are working, and highlights new approaches for helping families and friends care for people with AD.
- About The Scientists
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- Rapid advances in our knowledge about AD have led to the development of promising new drugs and treatment strategies. However, before these new strategies can be used in clinical practice, they must be shown to work in people. Advances in prevention and treatment are only possible thanks to volunteers who participate in clinical trials.
- Among those touched by Alzheimer's (excluding self), nearly one-third provide support as a friend or relative, another 3% provide support as a healthcare professional, and the remaining two-thirds provide no support to the person suffering from Alzheimer's. When support is provided, it most often entails emotional support, followed by care-giving support. While small in comparison, more than one person in ten is providing financial support. Read more.