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CHS Research News
Vol 17, Issue 2, Spring 2005

Feature Article

Successful aging: CHS research focuses on "thriving" while growing older

By Katie Saunders

By the year 2030, seniors will outnumber school-age children in many states—a demographic shift that raises the profile of "successful aging" in our nation. It’s a matter of "thriving, not just surviving," says Group Health Center for Health Studies Director Eric Larson, MD, MPH. As leading researchers in geriatrics, Larson and colleagues are among a cadre of scientists who are looking beyond issues of disease and disability to consider factors—especially those an individual can control—that increase the likelihood of aging successfully.

Most of us can probably point to people who epitomize successful aging, but coming up with a standard definition proves difficult. Is it simply living to a ripe old age? Or is it living a "quality" life, however that is defined? Is it adjusting and adapting to the changes and challenges of aging? Over the last several decades, researchers have attempted to nail down the notion of successful aging but no standard definition has emerged. This lack of an agreed-upon definition inhibits both health care providers and patients who might want to work together to make successful aging a reality.

To address this problem, Larson and University of Washington researcher Elizabeth Phelan, MD, MS, went straight to the source. In 2000, they surveyed elderly people about their views of aging well. Suspecting that ideas about successful aging are fluid, the researchers also asked seniors if their definitions changed over time. This direct approach contrasted with previous work, which focused on researchers’ own definitions of healthy aging—definitions that may or may not agree with older adults’.

Larson and Phelan surveyed about 4,500 adults aged 65 and older who were participants in one of two ongoing longitudinal studies of dementia and normal aging. The Kame Project consisted of Japanese Americans from King County recruited between 1992 and 1994; the Adult Changes in Thought (ACT) study included white Group Health seniors recruited between 1994 and 1996 who were free of dementia at the time of enrollment. The researchers recruited survey participants from the two groups because they presumed that differing cultural attitudes toward aging would translate into differing views of what it means to age well. (Asian cultures tend to honor their elders while American culture tends to place a higher value on appearing young).

Larson and Phelan’s survey included 20 statements that reflected non-repetitive definitions of successful aging gleaned from the scientific literature. The statements represented four larger domains of health—physical, functional, psychological (mental), and social. Respondents were asked to rate how important these statements were to characterizing successful aging. Examples of statements (and their domains) include:

• Remaining free of chronic diseases (physical)
• Having friends and family who are there for me (social)
• Being able to take care of myself until close to the time of my death (functional)
• Feeling good about myself (psychological)

The survey also asked whether participants had ever thought about successful aging and whether these thoughts had changed over the last 20 years.

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Self reliance ranks high in seniors’ views

One of the biggest surprises, according to Larson, was that the two groups of subjects were remarkably similar in their responses, with more than 75 percent of both groups endorsing the same 13 items as important to successful aging. Also, these 13 items encompassed all four dimensions of health (physical, social, functional, and psychological). This particular multi-dimensional view of successful aging did not correspond with any of the definitions previously put forth by researchers. In addition, the item "being able to take care of myself until close to the time of my death" (from the functioning domain) was rated most important to successful aging by the highest percentage of people in both cohorts. In contrast, the items "living a long time" and "being able to work in paid or volunteer activities after usual retirement age" were rated "not at all important" by the largest proportion of participants. Ninety percent of subjects reported having thought about aging and aging well and about two-thirds said their ideas about the subject had changed over the last 20 years.

Larson hopes that these unique perspectives on aging from older adults will contribute to researchers’ and providers’ understanding of the concept of successful aging, and ultimately, to their efforts to help people age healthily. Related to this ultimate goal, Larson has compiled the lists below of what is currently known about best practices for the "aging brain" and "aging body." These items, among other things, increase older adults’ chances of maintaining their independence in the face of advancing age.

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As Larson’s "Best Practices" lists show, exercise plays a prominent role in successful aging. Extensive research has demonstrated exercise’s benefits such as reduced mortality, improved cardiovascular health, reduced falls, enhanced physical function, reduced depression, and enhanced well-being. Some of these findings came from studies involving Group Health Center for Health Studies. For example, CHS senior investigator Andrea LaCroix, PhD, and others reported that seniors who walked more than four hours per week were 27 percent less likely to be hospitalized for cardiovascular disease than their counterparts who walked less than one hour per week. University of Washington scientist Linda Teri, PhD, in collaboration with Larson and others, found that simple exercise such as walking slowed the physical decline associated with moderate Alzheimer’s disease (AD) and that the benefits appeared to be long-lasting.

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Exploring the link between exercise and brain function

While exercise’s positive effects on physical health and functioning might seem intuitive, its potential impact on cognitive functioning is less so. However, some evidence suggests that aerobic exercise reduces the risk of cognitive decline and dementia. What’s the explanation? A 2003 University of Illinois study using MRI scans found that tissue loss in the brain, a process which begins in one’s 20s and is accompanied by loss of cognitive performance, was substantially reduced as a function of cardiovascular fitness in people 55 years and older. An intriguing observation is that the hippocampus, that part of the brain responsible for memory, gets smaller with age. Fitness and regular exercise reduce the loss of hippocampal tissue, presumably by improving blood flow to the brain and preventing damage. Another less direct explanation for the suggested relationship between fitness and cognitive ability is that traditional vascular disease risk factors, such as high blood pressure, have been increasingly implicated in the development of AD. Exercise helps control such risk factors, so it’s logical that an indirect effect on AD might be observed.

Larson emphasizes that the evidence linking exercise with enhanced cognitive function is mixed. However, given the domains of successful aging where the benefits of exercise are undisputed (i.e., physical health, physical functioning, mental health), Larson argues that the more important question is behavioral. Studies have shown that a small proportion of seniors engage in regular exercise and, if they do start, they are unlikely to sustain it over time. For example, one study reported that less than 40 percent of patients continued to exercise two years after having a heart attack.

"Quite simply, the problem with exercise is not so much whether it is beneficial or not, but how we encourage the behavior change that leads to habitual exercise," says Larson.

CHS is well positioned to shed light on this question. The Center’s staff includes several behavioral scientists who specialize in developing interventions to help people make healthy lifestyle changes (see CHS Research News Winter 2005). In addition, CHS is in the process of recruiting an investigator who specializes in exercise and diet.

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Research encompasses AD risk factors, chronic care issues, and more

Aside from an increased emphasis on exercise, CHS and Group Health are involved in other research related to healthy aging. Larson and colleagues have been studying Alzheimer’s disease (AD) since 1986, with one of the purposes being to identify risk factors, especially those that might be modifiable. AD poses one of the biggest threats to maintaining one’s independence, especially after age 85. The scientists are also investigating how certain medications, including nonsteroidal anti-inflammatories (aspirin, ibuprofen) and estrogen are related to AD.

The Seattle Longitudinal Study (SLS), led by K. Warner Schaie, PhD, of Pennsylvania State University, has an even longer history than Larson’s AD research. Every seven years since 1956, this study has recruited a random sample of Group Health enrollees, as well as followed up existing participants, to better understand how people develop and change from early adulthood to old age. Results from the SLS were among the first to show that cognitive-training interventions could improve mental abilities such as short-term memory and reasoning in older adults. Other researchers have extended Schaie’s and others’ work to studies of whether cognitive training improves older adults’ performance of real-world daily tasks such as food preparation and financial management.

Recognizing that mental health is an important component of successful aging, CHS has also been involved in studies designed to care for older people with depression. Project IMPACT was a collaborative-care model to improve the treatment of depression in patients aged 60 years and older at Group Health and eight other sites. Those in the enhanced model got care from a primary care physician and a depression nurse specialist supervised by a psychiatrist. The study reported in 2003 that after one year, 45 percent of intervention patients had at least a 50 percent reduction in depressive symptoms compared to only 19 percent of those with standard depression care.

The Chronic Care Model, developed by the MacColl Institute’s Ed Wagner, MD, MPH, and CHS colleagues, embodies a systematic, proactive approach to treating chronic conditions (see CHS Research News Winter 2002). Wagner and colleagues are currently testing the model among adults aged 75 years and older at some Group Health group and network model clinics. The researchers will evaluate whether functionally oriented assessments and individualized treatment planning delivered by an interdisciplinary Senior Resource Team (gerontologic nurse practitioner, pharmacist, and fellowship-trained geriatrician) result in less functional decline and less health care.

These are just a few examples of CHS’ efforts to contribute to the evidence base on how to maximize successful aging. As knowledge accumulates, Larson sees health care providers playing a prominent role in helping patients age healthily. In this capacity, doctors can help fulfill the 1955 motto of the American Gerontological Society that modern medicine was "adding life to years; not just more years to life."

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