What follows are reviews of recent research articles on factors that may be brain-protective and on intervention programs to maintain or improve cognitive skills. We will update this link with additional summaries as new studies are completed. Click on the links below to jump to the abstract you wish to read.
Theme: Cognitive training may be beneficial, even for older adults exhibiting mild cognitive impairment (MCI).
Background: Small-scale studies conducted over several decades suggested that cognitively-healthy older adults can improve their memory skills if they enroll in training programs that teach specific memory techniques (e.g., learning how to use mnemonics to remember names). However, this type of non-pharmacologic intervention had never been studied in a large-scale, scientifically rigorous manner, and it was not clear how general, or how long-lasting, the benefits of such training might be. The ACTIVE study (Advanced Cognitive Training for Independent and Vital Elderly) was designed to address these concerns. It is the first large-scale, randomized, controlled trial of cognitive training for healthy older adults.
Methods: 2802 healthy elders (age 65 or older) living in the community (of 6 different cities) received cognitive training that focused on specific thinking skills including: reasoning, memory and speed-of-processing. Each of these skills is important for complex everyday activities and living independently.
Training was conducted in small groups over a 5-6 week period, with 10 sessions of 60-75 minutes each (essentially, 2 sessions per week). Cognitive skills were evaluated at baseline (before training began), immediately after training ended, and at annual intervals.
In addition to the groups who received cognitive training, there was a no-contact control group that had cognitive tests at prescribed intervals, but received no education or training.
The results summarized below looked at training benefits for two subgroups of study volunteers: (1) those who had mild performance deficits on a standardized memory test (but no obvious dementia) at the start of the study; and (2) those who performed well on memory tests initially.
Study Findings:
Why this is important: This study demonstrates that older adults can benefit from an organized program of training in specific cognitive skills, even if they have some mild memory problems. Although memory training per se was not helpful to the memory-impaired volunteers, other types of cognitive skills did improve with training for these participants. That may be because some brain regions remain healthy and fully functional for older adults who are undergoing mild memory changes. Another important finding is that benefits persisted to some degree for at least two years. We do not know if the persisting benefits were a direct result of training or a "placebo" effect (e.g., due to improved confidence among participants that might have come about with any intervention).
Cautions: This study did not tackle the question of whether training benefited everyday life skills. An earlier analysis from the ACTIVE study (Willis and colleagues, JAMA, 2006) found that volunteers who received training did report slightly better maintenance of everyday skills for up to five years after training. But, there was little benefit of training on simulated everyday tasks. The question of strength of benefits (what researchers call "effect size") is an important question to ask about all types of treatments or interventions.
Reference:
Unverzagt FW, Kasten L, Johnson KE, Rebok GW, Marsiske M, Mann Koepke K, Elias JW, Morris KN, Willis SL, Ball K, Rexroth DF, Smith DM,
Wolinsky FD, Tennstedt SL. Effect of memory impairment on training outcomes
in ACTIVE. Journal of the International Neuropsychological Society 2007;13:953-960.
Further information about the ACTIVE STUDY:
Poster by Zelinsky EM, Yaffe K, Ruff RM, Kennison RK, and Smith GE, Presented at the Gerontological Society of America Meeting, November 16-20, 2007, San Francisco, CA
Theme: Computer-based cognitive training may be beneficial for healthy older adults.
Methods: Over 400 healthy, well-educated (>15 years education) older adults over the age of 65, with normal cognition (MMSE >26) were split into an experimental and control group in order to test the effectiveness of a computerized training program. The purpose of the program was to determine whether participants who complete a cognitive training program, designed to increase brain processing speed and "plasticity", improve on measures of attention and memory compared to participants who complete a control training program using a more traditional, education-based approach.
Experimental group: received the Posit Science Brain Fitness Program, a computerized training program with 6 comprehensive listening exercises focused on memory, speed of processing and brain plasticity (changes in information processing efficiency and flexibility).
Active Control group: received a program simulating physician recommendations for memory complaints via DVD-based education training on a computer as well as paper and pencil quizzes on memory and comprehension. This program was reported to be comparable in intensity, complexity and time, to the Brain Fitness Program regimen.
Training was conducted over a 10-week period, with sessions of at least 60 minutes per day, 5 days per week. Before and after training, participants were given neuropsychological tests of processing speed, attention, and memory which were different from the tasks directly involved in the Brain Fitness training program. They also completed a self-report questionnaire about their everyday cognitive abilities.
Conclusions: Compared to the active control group, participants in the experimental Brain Fitness group:
Why this is important: This is the first large, randomized controlled trial to show improvement in untrained measures of mental speed and memory as a result of computer-based cognitive training. Results also suggest that memory and attention can be improved by a specific, focused cognitive training program beyond what may be gained by general cognitive stimulation.
Limitations/Cautions:
Further Information: Posit Science's website (www.positscience.com) contains more information about the Brain Fitness program.
Theme: Older adults who have cognitively active lifestyles appear to have a reduced risk of developing Alzheimer's disease.
Methods: 700 older adults were recruited from continuing care retirement communities and subsidized housing facilities in the city of Chicago to participate in a research study (Rush Memory and Aging Project) examining risk factors for common health conditions in old age, including Alzheimer's disease. Three-fourths of the older adults were female, and 91% of the participants were white and non-Hispanic.
At the beginning of the study, participants rated their current and past frequency of cognitive activity, and then throughout the study, their current activity was measured at yearly clinical evaluations for up to 5 years. The study also gathered information on a variety of other factors, including: participants' physical activity, early life household socioeconomic status, mother's education, father's education and father's occupation; current income and income at age 40; vascular risk factors (i.e. diabetes, hypertension, smoking), and vascular conditions (i.e. heart attack, stroke, congestive heart failure).
During the study, assessment of cognitive function was measured by a battery of 20 cognitive tests that focused on cognitive measures such as episodic memory, semantic memory, working memory, perceptual speed and visuospatial ability.
Results:
Why this is important: This large prospective study shows a fairly strong correlation between cognitive activity and risk of developing dementia. It is one of several recent studies that provide support for the hypothesis that keeping the mind active is beneficial for maintaining a healthy brain.
Limitations: This is an observational study. It measured relationships between predictors (cognitive activity) and outcomes as they occur in natural settings. It does not establish a cause-and-effect relationship between mental activity and risk of Alzheimer's disease. For example, reduced cognitive activity may simply be an early (preclinical) sign that a person is already developing Alzheimer's disease.
Controlled clinical trials, where participants might be assigned to different cognitive activity regimens and then followed long-term, would be the best way to understand cause-and-effect relationships between mental activity and Alzheimer's disease, but there are many practical obstacles to doing such studies. One approach to learning more quickly about the potential benefits of treatments or preventive approaches is to study the effects of the intervention on biomarkers for Alzheimer's disease pathology (e.g., functional neuroimaging profiles) that may be precursors of the clinical Alzheimer's disease syndrome.
Reference:
Wilson RS, Scherr PA, Schneider JA, Tang Y, and Bennett DA. Relation
of cognitive activity to risk of developing Alzheimer's disease.
Neurology 2007:69;1911-1920.
Other epidemiologic studies on cognitive activity and Alzheimer's disease risk:
Theme: Physical activity may benefit cognitive function among older adults at risk for Alzheimer's disease.
Background: Observational studies have shown that people who are physically active appear less likely to develop cognitive decline and dementia later in life. This finding has been confirmed by prospective studies which reveal an association between physical activity and reduced incidence of dementia. Interestingly, this association has been evident even if exercise is only implemented later in life. The problem, however, was that randomized, controlled trials had not yet tested this observation. The following study aimed to address this problem.
Methods: 170 adults aged 50 or older (average=69 years) who reported memory problems- but did not meet criteria for dementia- were randomly assigned to a usual care group or to a physical activity group. 100 of the 170 participants had objective evidence of mild cognitive impairment (MCI) on a cognitive screening battery. Persons with significant physical or mental health problems were not included.
Results:
Why this is important: This was the first randomized trial to demonstrate that a program of physical activity can improve cognitive function in older adults with mild cognitive impairment. The degree of improvement on cognitive testing among the physical activity group members was modest, but it was greater than the cognitive benefits reported in a comparable study of treatment with cholinesterase inhibitor over an 18-month period. The main appeal of this study is that an intervention as simple and widely available as walking has measurable positive effects on cognition. Moreover, the measurable benefits of exercise may extend beyond improved cognitive function, to areas of more general health.
Cautions: Although this study demonstrates the potential benefit of exercise in maintaining brain health, there are some limitations to the conclusions we can draw from it.
Reference:
Lautenschlager, Nicola T, MD, Cox, Kay L, PhD, Flicker, Leon, MBBS,PhD, Foster, Jonathan K, DPhil, Bockxmeer, Frank M,
PhD, Xiao, Jianguo, MD, PhD, Greenop, Kathryn R, PhD, Almeida, Osvaldo P, MD, PhD. Effect
of physical activity on cognitive function in older adults at risk for Alzheimer
disease. JAMA, 2008; 300(9):1027-1037.
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