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Healthy Aging: What Is It? Are There Acceptable Markers to Utilize in Developing Strategies to Promote It?
Moderator Simin Meydani, director, Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging, Tufts University, opened the final session of the workshop, a panel discussion, with introductory remarks on how the notion of successful, or healthy, aging has changed over time to encompass more than simply the absence of disease or functional impairment. She then asked each of the four panelists of this session to provide their reflections on the workshop presentations and discussions. These comments were followed by an open discussion with the audience.
MEYDANI’S REMARKS
Meydani began by presenting some of her thoughts on healthy aging, informed by the workshop discussion. First, she called attention to some aging statistics that show, she said, “the burden that this could have” on society. One is that in the 1930s, for every retiree, another 16 people were still working, while by 2030, there will be only 2.2 working people per retiree. Another, Meydani said, is the cost associated with the care of chronic diseases. In her opinion, then, developing strategies for increasing the “health span” is critical, both socially and economically. Developing these strategies in turn will require understanding what leads to successful aging, she asserted, including the genetic, lifestyle (including psychosocial interactions), and environmental factors that determine both rate of aging and disease susceptibility. She stated that as yet, there is no consensus on
what these factors are—that is, what constitutes healthy aging—a question that remains a major challenge for the field.
Healthy aging used to be defined in terms of the absence of disease, Meydani continued, whereas today’s definitions revolve around an understanding that healthy aging is not merely synonymous with lack of disease or functional impairment. She referred to early work by Rowe and Kahn (1987), who, in addition to freedom from disease and disability, considered successful aging to be characterized by having high cognitive and physical functioning, social and productive engagement, and resilience. As one example of the many subsequent attempts to develop an index of successful aging, she cited a study of 2,663 elderly persons (aged 65-100) in the Mediterranean basin. She explained that Tyrovolas and colleagues (2014) found that a multidomain approach—one that accounted for low probability of disease and disability (“clinical characteristics”), high cognitive and physical capacity (“lifestyle characteristics”), and active participation through social activities (“psychosocial-economic characteristics”)—better predicted different health outcomes (e.g., use of health care services) than any single domain indicator. She called attention to the fact that in this study, lifestyle characteristics accounted for 48 percent of the variance in successful aging, while psychosocial-economic factors accounted for 23 percent, leaving only 38 percent explained by clinical characteristics.
Meydani also emphasized that studies of successful aging vary considerably in the proportion of individuals considered to have aged successfully depending on how successful aging is defined. She explained that studies of self-rated successful aging result in much higher percentages of successful aging relative to studies based on the definitions of health care workers (Depp and Jeste, 2006). For Meydani, this trend raises an important question: Who should define successful aging, and should older people themselves be providing input?
Meydani referred to other work showing that cognitive performance declines more rapidly with increasing age among people with limited as opposed to average social engagement, and that it declines more slowly among people with more extensive social connections (Haslam et al., 2014). She views social interactions among older adults as important not only for their cognitive functioning but also for the opportunities they provide for food and nutrition interventions (i.e., delivery of healthy foods).
To conclude, Meydani reiterated that there are many ways to define successful aging, including both objectively and subjectively. She observed that while most older people may not meet objective definitions of successful aging, they do meet subjective measures (Jeste et al., 2010). From the perspective of older adults, she asserted, the absence of disease is much less important than independent living, self-rated successful aging, life satisfaction, and several other factors.
PANELIST REMARKS
Following Meydani’s presentation, each of the four panelists was asked to present 5 minutes of thoughts on healthy aging.
“Successful aging is living,” began Frank Busta, director emeritus, National Center for Food Protection and Defense, and professor emeritus of food biology, University of Minnesota. “Even if you have an illness and disease, you bypass that, and you live.” As a microbiologist, he was delighted that the microbiome is being examined over the lifespan, and he suspects that in the near future, this knowledge will have a tremendous influence on healthy aging, given that only part of what people ingest is used to support them directly, with the remainder supporting their microbiome. The many aspects of healthy aging, he continued, including bone structure, skeletal muscle, digestive tract health, appropriate weight, and others, create what he described as a “challenge of choices.” In his opinion, the social aspects of healthy aging are extremely important. He observed that he had not heard much about behavior modification at the workshop, yet in his opinion, it is “terribly significant.” People know what they should be eating, he asserted, but so many things are associated with food (e.g., socializing, entertainment) that behavioral change is a “tremendous challenge.” Some people are capable of meeting this challenge, he suggested, but many have a very difficult time with it, especially those struggling with overweight or obesity. He knows many older people who say, “I am going to enjoy myself. If it cuts 5 years off my life, so be it,” an attitude that also raises questions about when in a person’s life it is no longer appropriate to intervene.
Mary Ann Johnson observed that much of the workshop discussion had revolved around what she described as “aging process markers.” By aging process, she meant the fundamental biological processes of aging. Among gerontologists, whether a process is part of aging or a disease is often the topic of extended conversation. She referred to a December 2015 series of articles in Science on this question. In her opinion, physical function (as measured by walking speed, strength, and so on) and living independently (as measured by social engagement) are two markers of the aging process of particular practical significance. Additionally, she noted, while inflammatory markers may not indicate what is wrong, they indicate that something is wrong. Thus, they serve as integrative markers that cut across multiple domains.
In addition to her comments on markers, Johnson called on nutritionists to learn to speak the language of the people who make daily differences in the lives of older adults (e.g., the aging services community, the medical community). “Gait speed,” for example, is something professionals in these other communities understand, she said, whereas deficiencies in vitamin D or B12 are not. More generally, she encouraged thinking about how to be
partners with and influence the health care system and to find ways, for example, of incorporating nutrition services into care transitions so that older adults are not readmitted to hospitals so quickly.
A workshop message that reverberated for Janet King was the complexity of the aging process. Aging does not begin at age 50, 70, or 90 but in utero, she observed. Because aging is a lifelong process, she continued, healthy aging requires thinking about the lifespan from the very beginning. Moreover, she added, people age differently, some faster than others. When thinking about interventions, she stressed the importance of keeping in mind the socioeconomic context of aging and ensuring that recommendations for interventions can apply to everyone. While speakers at the workshop had identified improving social contacts and cognitive function, for example, as important healthy aging interventions, she works in the poorest part of Oakland, California, where many elderly people lack the resources to participate in those interventions. She suggested identifying key targets that are simple and easy to comprehend and can be communicated to the public. She cited maintaining a certain walking gait (e.g., being able to walk 1 mile in 15 minutes) as an example of something everyone can understand.
Regarding what people should be eating for healthy aging, King found it difficult to offer an answer because no one food can serve this purpose. Despite all the talk about fruits and vegetables, she believes it is time to look critically at nutrient recommendations and start thinking about Dietary Reference Intakes (DRIs) for people aged 51-70 and 71 and older, and then translate those nutrient requirements into food patterns and simple targets. In her opinion, not even ChooseMyPlate is simple enough. She suggested a recommendation such as, “Make sure you have a good source of protein once a day.” Not only would meeting that recommendation result in ingesting many micronutrients, but also, according to King, some experts are beginning to think that protein needs may grow higher as one ages and that older adults tend to reduce their protein intakes naturally.
King also observed that this workshop had been a meeting primarily of nutritionists. While nutrition clearly plays a role in the aging process, she asserted, so do many other disciplines as well. In her opinion, it is critical that the issue of healthy aging be addressed in a multidisciplinary way, not through food alone.
The fourth and final panelist, David Reuben, suggested that older people are “painted” as adults with gray hair and wrinkles. “In fact, they are not,” he said. He acknowledged many people’s desire for 90 to be the new 70. If someone’s goal is to be 70 at 90, he suggested, then some of the traditional biomarkers of successful aging are the appropriate focus. However, he argued, it takes a lot of work to be 70 at 90, and many people do not want to work that hard. Moreover, he added, geriatricians work with many frail people, often with incurable diseases such as Alzheimer’s.
Rather than geriatricians telling people “this” is how they should be at 90 or at 85, he said, “it’s really about what you [the patient] think you should be at 90 or 85 or now through the next 5 years.” He commented on the body of literature that exists on the topic of goal setting and goal attainment and suggested that it may be a useful resource. In his practice, he sits down with patients and asks them what they want to achieve. Some of his patients want to be able to watch television with their families, have people over, visit, and so on. He helps them set goals and develop a strategy for meeting those goals, even though sometimes the goals may not resonate with him as a physician.
While Meydani agreed with Reuben that seeking input from older adults about what matters to them is important, she also stressed the need to develop some tangible measures of successful aging. She argued that health care providers need markers to identify at-risk people and know when intervention is appropriate, governments need markers to develop recommendations for older people regarding nutritional intakes or other lifestyle changes, and the food industry needs markers so they can develop products to meet targets.
PANEL DISCUSSION WITH THE AUDIENCE
Following these remarks, Busta asked about public use of the Dietary Guidelines for Americans (DGA). Angie Tagtow, Food Forum member, replied that any federal agency that implements a food or nutrition program is supposed to apply the guidelines. Thus, she asserted evaluating the impact of the DGA requires examining all of their federal applications and the number of individuals, families, and communities that are impacted by these federal programs. She noted that the Center for Nutrition Policy and Promotion (CNPP) also relies on practitioners and policy makers to apply the guidelines, which she said is more difficult to measure. She cautioned against making any direct connection between the DGA and overall population health given the numerous confounding variables. She also encouraged looking beyond individual-level interventions and adopting a more systematic approach and, she said, “calling everybody to the table.” Meydani asked whether there is a record of how many people have actually visited ChooseMyPlate.gov. Tagtow replied that CNPP measures a wide array of process outputs as part of its Web analytics. To illustrate, she noted that as of the week before the workshop, SuperTracker, an online tool designed to help individuals apply the DGA, had almost 7.4 million registered users. She commented that the small size of the agency is a limiting factor with respect to reaching all 321 million Americans, which in her opinion makes it all the more important that other federal agencies as well as intermediaries apply the guidelines.
Recognizing how difficult the DGA process is, having worked on the guidelines herself in the past, Wendy Johnson-Askew challenged the process. “They [the guidelines] were intended for healthy individuals,” she said, “and our population is not healthy.” In her opinion, the guidelines need to be translated for individuals based on where they are, not “where we think they should be.”
Johnson-Askew also responded to Busta’s remarks about behavior. Even in the context of the socioecological model, she said, the individual is still at the center, and thus, individual behavior needs to be driven. She challenged the scientific community, especially researchers who examine behavior, to think about ways of understanding the behavior proclivities of individuals so interventions can be tailored to their needs. Meydani agreed that understanding how behavior can be changed will be helpful for implementing nutrition recommendations. However, she argued, the first step to a behavioral change intervention is understanding what needs to be changed. In terms of successful aging, she asserted, it is unclear what needs to be changed. In her opinion, the parameters of successful aging need to be understood before interventions can be developed. For Johnson-Askew, the first step is to understand how behavior can be changed. She made a call to capitalize on what scientists in other fields have been learning about behavioral phenotyping (e.g., in relation to drug adherence).
Sharon Donovan, workshop participant, said she was struck by the demographics of the aging population. “If we are not doing something,” she said, “this country is going to be in for a world of hurt.” But she also views the current demographics as an opportunity for research. She has observed a disinvestment of the National Institutes of Health (NIH) in nutrition research over the last 20 years. She cited the lack of nutrition research on the 0 to 24-month age group in particular and said she suspects that the same is true of the elderly. Moreover, she noted, most DRIs have not been reevaluated since they were issued. In her opinion, no one really knows what percentage of the older population is meeting recommended nutrient levels. She asked, “Why do we have a cancer moonshot and we don’t have a baby boomer moonshot?” She underscored the current opportunity to enroll a very large cohort (i.e., the baby boomers) in long-term studies that could involve lifestyle interventions, supplements, and other factors. She called for building an evidence base with the appropriate outcomes that are going to have an impact and urged considering interventions beyond those that are behavior-based, given the challenges of adult learning. Johnson agreed that answering many of the questions raised in the workshop will require 10-, 20-, or 30-year studies to see how the aging process plays out.
Meydani agreed on the urgency of understanding the needs of older adults, given the impact not just in the United States but around the world. She observed that most of what is known about the nutritional status of
older individuals is based on dietary intake. But, she asserted, dietary intake does not necessarily reflect what is going on in the body. For example, she said, while dietary intake of zinc might not be considered low, in fact 20 to 30 percent of older adults have low serum zinc levels, with potential health consequences. Much remains unknown, she observed, and funding for the necessary research is inadequate. She noted that funding for the National Institute on Aging (NIA) has not increased (although Reuben noted later that the NIA has received increased funding, but that funding has been earmarked for research on Alzheimer’s disease).
Johanna Dywer mentioned the many National Academies of Sciences, Engineering, and Medicine reports on aging that have been issued over the past 25 years. More important, she said, she recently received a letter from her long-term care insurance carrier notifying her that her quarterly premiums had increased from $375 to $1,400, and that at least a 15 percent increase would follow in 2017. Many people will not be able to pay these increasing premiums, she observed, and the cost of their care will become public responsibility. “There is a tsunami coming of people over 85, and I’m not sure we can deal with that with the kinds of thing we have been talking about,” she said. Reuben agreed that these are major societal issues that keep being kicked down the road. By 2030, he noted, 20 percent of the U.S. population will be aged 65 or older, and he suggested that over the next decade or so, “The hand is going to be forced to make the choices to start addressing these problems in real time.” Johnson added that conversations around these issues are beginning to take place, including at the federal, state, and local levels. Much of this discussion, she said, is focused on rebalancing long-term care in a way that keeps people at home and out of nursing homes through home- and community-based services. A big part of these services, she observed, is foods and meals.
CLOSING REMARKS
In closing, Meydani asked the panelists whether there are any markers for healthy aging that could be utilized now and if not, what the next step should be toward compiling a set of such markers. Reuben suggested that there are indeed some existing and some emerging physiological and psychological markers, but there is also a third category—personalized markers based on individuals’ perceptions of their own healthy aging. King encouraged thinking about early determinants of inappropriate aging processes, such as inflammation. Johnson agreed with Reuben on the need to identify markers based on what older adults themselves consider to be important, but she suggested that markers also need to be developed based on what programs and payers perceive to be important. Finally, Busta said, “I think the marker of successful aging is being proud of how old you are.”
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