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"I often tell people that my grandmother lived to be 99," says Marilyn Albert. "They would sometimes ask me if that was the reason I decided to study aging and I would say, 'No.' I've since realized that that's not true, that she probably was the reason."
Albert's grandmother, Rose Silbermann, was mentally intact until the day she died. She was interested in the world, Albert recalls, liked to talk about everything that was going on in her family, and determinedly and admirably independent. Albert remembers the home-cooked food her grandmother would unpack after bringing it from the Bronx to Manhattan on the subway. After her husband died, she lived on her own until three months before her own death. "I always felt comfortable with her," Albert says. "She looked very old but she was comfortable with herself and that comfort put me at ease. This ingrained in me that aging was something positive."
More and more researchers are looking to the Rose Silbermanns of the world for information about successful aging. She, Henrietta Aladjem, and Ruth McShane sound so unusual because they defy our notions about aging. Although about 1.7 million Americans live in nursing homes, they constitute only 4.5 percent of the over-65 population. The rest of the elderly live in homes: houses, apartments, retirement communities, with in-laws, or in assisted-living facilities. However you count them, the vast majority of elderly are noninstitutionalized participants in society, albeit with widely varying degrees of independence.
In the early 1980s, when the MacArthur Foundation decided to devote funding to studies of successful aging, Albert, Jack Rowe, and Lisa Berkman (now Norman professor of health, social behavior, and epidemiology at the Harvard School of Public Health), were some of the first researchers to become involved. The results of a recently released collaborative study draw strong connections between preserved cognitive function-an important component of successful aging-and education, physical activity, and lung function.
Although the link between education and successful aging seems firm, its implications are not entirely clear. It is possible that higher education could substitute for environmental factors the study didn't measure, such as better health care. Or perhaps formal schooling enables people to perform better on tests. The explanation Albert feels is most plausible is that mental activity produces lasting change in the brain itself-proliferation of nerve cells, for example-that may serve the brain in good stead in years to come. "Just having more synapses may make the brain more resilient to stress, even the stress of cognitive degeneration," she says. "This change may be produced by education early in life, but we hope it also is effected by lifelong habits of mental activity."
That's a small piece in a larger puzzle. "Normal, successful aging is an interesting and vital way to study the aging process," says the medical school's Ken Minaker. "We're focused on provoking the system, stressing it, and then watching it recover. For example, in the elderly, there's an erosion of capacity to tolerate extremes of too much or too little salt. Older patients are frequently on the brink of over- or under-hydration. Under these conditions, simple illnesses such as a mild fever can precipitate severe dehydration."
In one set of experiments, Minaker looked at the capacity of elderly people to regulate fluid and electrolyte balance in their bodies. This is a common source of problems; dehydration costs some $400 million to $600 million in hospitalization and treatment each year, primarily among the elderly. In some cases, people become disoriented and may temporarily appear demented. "What we've found," says Minaker, "is that in adapting to different conditions, elderly people 'get there'-they make the adjustment-but it takes them more time and they do it by different mechanisms than younger people."
If you've ever watched an older tennis player on the court, you can visualize what he is talking about. Lost mobility encourages restraint. Players learn that if they take fewer chances, they stand a much better chance of returning the next volley. Likewise, the body learns that recovery from stress is a process best undertaken cautiously, with one eye toward what's coming next.
"There's a tendency to muddle through," Minaker says. "I think that advancing age means adapting to limits on maximum capacities that allow people to adjust, but without doing self-damage. Physiologically, age is a time of adaptation, when compensatory mechanisms adjust in order to fight off challenges and keep self-regulated. You can't tolerate severe challenges, but for little hits you manage pretty well."
As a result, the aging body seems capable of much more than has been widely acknowledged. In many cases, it's not the depredations of aging itself that cause disease, but factors outside the body: infection, behaviors like diet, smoking, lack of exercise, and the social environment. And most of these factors can be modified; they don't bear the permanent stamp of genetic birthright.
More signs on the route to successful aging come from the interface of social sciences and medicine. It's now becoming clear that keeping up social connections and interpersonal contacts-friends, family, and community-matters as much as mental and physical fitness. Lisa Berkman began thinking about this issue when she worked at a family-planning clinic in San Francisco. She observed what she was later to call "a protective web of social networks."
"It struck me that those people who were most disconnected and socially isolated were vulnerable, and were in trouble across a lot of domains," recalls Berkman. "On the other hand, people who were really connected to their communities were doing really well."
She decided to investigate the connection further, despite the obvious pitfalls of looking for connections between health and such hard-to-define variables as social support. Her research demonstrated that people with no close ties to friends, relations, or the community were three times more likely to die over a nine-year period than those with at least one source of social support.
"It's clearly a two-way street," says Berkman, now chair of the School of Public Health's department of health and social behavior. "It's clear that people by the nature of their illness undergo social and psychological changes that are consequences of illness, like the loss of social contacts. However, it also seems that social circumstances like isolation precede and predict the onset and course of illness. My question was, how could something that's 'outside' your body-like social support-get 'inside,' and what are the pathways through which it could get inside?"
Berkman is forging the next link by looking for the biochemical effects that social contacts might have. She's focusing on levels of hormones that increase in response to stress; repeated exposure to these hormones may leave elderly people more vulnerable to all types of illnesses, such as heart disease. She is also testing interventions to see if prognoses may be improved with alterations in social support.
"People thought it was normal to experience health and functional declines with age and that it was all determined by genes," Berkman says. "Today, more people recognize that the key to aging is in large part related to conditions we can do something about, like the social environment, behaviors, health practices, and kinds of experiences we have in midlife. The key to extending life lies in genes and in how we're living."
