Building Cognitive Reserve
Now that PET scans with PiB can measure beta-amyloid levels in a living brain, studies have found that about 25 percent of seventy-year-olds have evidence of one pathology of Alzheimer's disease—beta-amyloid plaques—even without showing clinical symptoms of memory loss or cognitive decline. Although these people are cognitively normal, they have a substantial plaque load.
Dr. David Bennett, the director of the Rush Alzheimer's Disease Center at Rush University Medical Center in Chicago, has been researching this phenomenon. He is intrigued by cases like a ninety-year-old nun who had shown no decline in cognition, but was found to have a substantial amount of beta-amyloid plaques upon autopsy. He wondered how she could have so much beta-amyloid in her brain, but experience no evident memory loss.
Scientists do not doubt that beta-amyloid changes the brain, but researchers like Dr. Bennett are focusing on what enables some people's brains to withstand what could be damaging effects. Do they have a bigger brain, a better brain, a more efficient brain, or something else? In some cases, the brain may have some sort of "cognitive reserve," the ability to operate effectively even while damage is occurring.
Alzheimer's disease researchers, such as Dr. Bennett, are working to understand why some people have these brain reserves, which seem to protect them from the presumed damage by beta-amyloid. What protective role might brain efficiency play? Could different personality traits make someone more or less susceptible to AD? How might early life experiences and lifelong behaviors affect the disease?
In particular, Dr. Bennett is studying the possible impact on the aging brain of behavior, lifestyle, and education. As the lead researcher on two major observational studies—the Rush Memory and Aging Project and the Religious Orders Study—he heads a team that is collecting detailed family histories, socioeconomic data, and records of performance on cognitive exams over time from more than twenty-three hundred individuals and retirement home residents, including older Catholic nuns, priests, and brothers living in forty communities across the United States. All participants agree to donate their brains to science upon their death and, to date, Dr. Bennett has collected more than seven hundred brains to study. A third of the people enrolled in the study, including the nun described above, are found upon autopsy to have fully developed Alzheimer's disease plaque pathology without any obvious cognitive problems. He hypothesizes that cognitive reserve may be preventing these brains from expressing clinical signs of Alzheimer's disease.
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Next: Brain Efficiency
Excerpted from THE ALZHEIMER'S PROJECT: MOMENTUM IN SCIENCE, published by Public Affairs, www.publicaffairsbooks.com.
In This Section
- Building Cognitive Reserve
- Brain Efficiency
- The Role of Education
- Brain Building
- Personality Factors and Social Networks
- Assessing the Potential Benefits of Exercise and Diet
- Exercise and the Brain
- Diet and the Brain
- Developing New Drug Treatments
- Drugs in Development
- Practical Challenges
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
Connect with Alzheimer's Research
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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.