What works to protect cognition

As many as 5.3 million Americans have Alzheimer’s disease, according to the National Institutes of Health. The disorder is now the seventh-leading cause of death across all ages in the United States and the fifth-leading cause of death in Americans age 65 and older. Meanwhile, the prevalence of mild cognitive impairment — problems with memory, language or other mental functions that do not yet interfere with daily living — is thought to be even higher.

“Cognitive decline in late adulthood is becoming the No. 1 public health problem we face as a country, particularly as the baby boomers age,” says psychologist Denise C. Park, PhD, director of the Center for Vital Longevity at the University of Texas at Dallas.

With their expertise in neuroscience, learning and memory, psychologists have an important role to play in sustaining — and perhaps even improving — brain function among older adults, say experts in the field.

“We bridge quite a broad range as a discipline, and all of the specialties within psychology have a critical piece of the puzzle in trying to understand how best to intervene to help older adults,” says Neil Charness, PhD, a member of the APA Committee on Aging and a principal investigator of the Center for Research and Education on Aging and Technology Enhancement (CREATE), a National Institute on Aging-sponsored program with the University of Miami, Georgia Institute of Technology and Florida State University.

Over the past 20 years, psychologists have identified several modifiable lifestyle interventions to prevent dementia. Those that show the most promise in keeping the mind sharp include physical exercise, mental stimulation, stress reduction and real-life skills training, says clinical neuropsychologist Paul David Nussbaum, PhD, professor of neurological surgery at the University of Pittsburgh School of Medicine. Nussbaum points to several suggestive studies examining these lifestyle effects on the brain:

• Exercise: A study in the January Archives of Neurology (Vol. 67, No. 1), led by Laura Baker, PhD, a clinical neuropsychologist at the University of Washington, found that older adults with mild cognitive impairment showed significant improvements on tests of executive function after six months of four-day-a-week aerobic exercise.

• Stress reduction: In a 2007 study published in Proceedings of the National Academy of Sciences (Vol. 104, No. 25), researchers led by neurologist David Holtzman, MD, at Washington University in St. Louis reported that short-term stress leads to an increase in the amount of beta-amyloid protein — a key component in the development of Alzheimer’s — in the brains of mice.

• Mental stimulation: A 2006 meta-analysis conducted by a group of Spanish scientists and published in Neuroepidemiology (Vol. 26, No. 4), links fewer years of education to a greater risk of Alzheimer’s disease. “It seems that the more complex and novel the environment, the more likely the benefit to the brain,” Nussbaum says.

Yet some researchers say there’s still a lack of controlled research offering clear cause-and-effect conclusions that these interventions improve brain function. In April, the National Institutes of Health convened a “State-of-the-Science Conference: Preventing Alzheimer’s Disease and Cognitive Decline,” in which an independent panel of experts concluded that there is not enough evidence to support that any particular modifiable factor reduces the risk of dementia.

“These and many other lines of research may show promise, but at the moment, we can’t say with any confidence that they work to reduce Alzheimer’s or prevent cognitive decline,” says panel member Jacqueline Dunbar-Jacobs, PhD, of the University of Pittsburgh.

The panel’s assessment revealed that progress in understanding factors that may delay or prevent the onset of dementia is limited by inconsistent definitions of what constitutes Alzheimer’s disease and cognitive decline. To address this, Dunbar-Jacobs says, the research community and clinicians must collaborate to develop, test and uniformly adopt objective measures of baseline cognitive function and changes over time. The panel is also advocating long-term, longitudinal studies that would better characterize the natural history and progression of these diseases. The panel recommends the creation of a large, multicenter registry for Alzheimer’s disease and cognitive decline, modeled on existing registries for cancer.

Dunbar-Jacobs points out, however, that while no lifestyle changes have yet been proven to fend off cognitive decline, that does not necessarily mean efforts to keep the brain healthy don’t work. “There’s just not sufficient high-quality research to make recommendations to the public,” she says.

Neural circuits or ‘scaffolds’

How might a healthy lifestyle work to protect brain health? A 2009 neuroimaging study led by Park, at the Center for Vital Longevity, offers some clues: As we age, when we are given a demanding task, there is increased activity in our brains’ frontal regions, which requires our brains to develop new neural circuits, or “scaffolds,” as Park calls them. This scaffolding may also protect our cognitive function and may be strengthened by cognitive and social engagement and physical exercise (Annual Review of Psychology, Vol. 60).

To test this scaffolding theory and perhaps shed light on how to enhance brain health and longevity, Park and colleagues are looking at whether acquiring new, real-life skills can preserve cognitive function among older adults. In her Synapse Study, funded by the National Institute on Aging, researchers are randomly assigning participants to one of several activity groups in which they learn, for example, digital photography or how to quilt. Two years ago, the team also received a grant to incorporate an exercise component into each group.

Participants spend a minimum of 16 hours a week for three months working in groups on their assigned projects, and they must undergo fMRI scans and written tests to measure their brain function before and after the 12-week sessions, and again one year after the intervention ends, Park says.

“What’s different about Synapse is that rather than just engaging in training, it really teaches people how to learn new things, so that even after they leave the Synapse setting, they can continue to develop new skills,” she says.

To date, more than 250 older adults have participated. Although the study results are not yet published, a pilot study Park conducted while at the University of Illinois showed that a similar program significantly increased older adults’ working memories.

Research by geropsychologist Leon Hyer, PhD, of the Georgia Neurosurgical Institute is also using Park’s scaffolding theory to develop interventions for older adults with age-associated memory impairment or mild cognitive impairment. In an ongoing study with 60 older adults, Hyer is training participants and their caregivers on how to use memory acronyms, mnemonics and association techniques to improve working memory and attention. Participants also commit to an exercise program, follow a heart-healthy diet, and receive training in meditation and relaxation to help with stress management.

Initial results point to the program’s success: When participants begin the program, most can recall two or three words after they’re shown a list of 15. After the course’s six weekly sessions are complete, Hyer says, most can recall all 15.

While encouraged by this pilot intervention, like many others who are somewhat skeptical of current interventions to fend off cognitive decline, Hyer admits the program merits more expansive study, interpretation and application before being pronounced a durable strategy for promoting brain health.

“Science is arrogant as it assumes that nature is predictable, has a rhyme and reason, and that we can discover it,” he says. “The brain is resisting this. There will be fits and starts for many years until we have a good theory of the aging brain and we can validate it.”

Amy Novotney is a writer in Chicago.