Successful aging lacks a clear definition. Elizabeth Saenger, PhD, Medscape Psychiatry & Mental Health Program Director, speaks with Dilip Jeste, MD, Director of the Institute for Research on Aging, University of California, San Diego, about the impact of the mind and the body on aging. How do they influence and predict success?
Medscape: How do you define successful aging?
Dr. Jeste: Successful aging has not been consistently defined; that is one reason why this area is ideal for research. There have been some studies funded by the MacArthur Foundation beginning in the mid-1980s going on through the mid-1990s. But the [scientific] literature is limited, and there is no consensus on what is successful aging. Our research goals include developing a definition as well as criteria for successful aging.
At this stage, we think that there are several elements or domains that are important constituents of successful aging:
Higher level of cognitive functioning;
Adaptation to changes associated with aging;
Socialization -- that is, some kind of social activity and/or social contacts; and
It is also important to say what is not an essential part of successful aging -- absence of either physical diseases or physical disability is not necessarily a part of successful aging. I want to stress that people who have physical illnesses or physical disabilities can be aging successfully. However, severe dementia or severe mental illness cannot be a part of successful aging. Optimal functioning of the brain and mind are primary components of successful aging.
Medscape: Can you tell us a little bit more about those different components? What has your research uncovered about cognitive functioning, adaptation to change, and so on?
Dr. Jeste: About 1 year ago, when I took on my current position at the Institute, we started to consider what defines successful aging by first reviewing the existing literature. But, as I already mentioned, the literature is limited. There are several reasons for the lack of literature on successful aging:
The definition has been inconsistent.
It is not clearly diagnosable.
There is a stigma about aging -- a kind of cultural belief that successful aging is a misnomer or even an oxymoron.
Aging is associated with loss of abilities, illnesses, dementia, and depression. Many believe that life just goes downhill in old age. Given that kind of pessimistic, almost nihilistic, attitude towards aging, people have not focused on aging successfully. At the same time, the population is growing older, and increasing numbers of people are living healthy, functional lives well into old age.
After completing our literature review, we started to look at people from San Diego County living in retirement communities as well as those attending an extension course at University of California, San Diego (UCSD) called Institute, available for retired or semiretired people to take classes or seminars. The third and largest cohort from whom we are collecting data is the Women's Health Initiative (WHI). As you and many readers may know, WHI is a very large National Institutes of Health (NIH)-sponsored study that has been going on for the last 12 to 13 years or longer. It involves roughly 150,000 women in the United States. For our purposes, we evaluated the contingent of women from San Diego County; there are about 6000.
We have been conducting surveys in each of these 3 groups of subjects, most of whom are over the age of 60. After gathering background, demographic information, and a medical history, we ask them whether they think they're aging successfully, and we have them rate themselves on a 1 to 10 scale. We also ask about physical illnesses, disabilities, health behaviors (smoking, drinking, etc.), physical activities such as exercise, mental activities like participation in classes, and use of computers. Then, we ask a series of questions about their resilience -- how they adapt to the changes of aging -- and whether they feel that they have control over their lives. Finally, using rating scales, we ask them to rank factors like their level of function and quality of life.
We have found that a surprisingly large proportion of older adults surveyed report that they are aging successfully; our results also suggest that this perspective, this self-perception, is not related to type of physical illness or degree of disability. People can have diabetes, hypertension, arthritis, even cancer, heart disease, or stroke and still age successfully. The key seems to be for one's brain and mind to function at optimal levels.
Medscape: Can you speak more about resilience?
Dr. Jeste: To measure resilience, we use the Connor-Davidson Scale which is designed to find out how people adapt to stress and to change. To some extent, changes are inevitable with aging -- loss of mobility from arthritis, for example, or problems with vision or hearing, financial stress from retirement, and loss of friends, family members, or even one's spouse.
In many cultures, there is a stigma associated with aging -- a sense of lack of value or lack of self-esteem, often related to the way the society views aging. In addition, healthcare costs go up. These particular stresses are, for the most part, universal; the question is how do people adapt to these stresses? That's where people differ. One person may be totally overwhelmed with a physical illness or loss of a near and dear one, while someone else is stressed out for a short time, but then recovers from the situation and adapts to the change in a positive way.
Medscape: What makes some people react in one way rather than another?
Dr. Jeste: That's a billion-dollar question! It seems that both genes and environment play an important role. Genes play an important role not only for longevity, but also for how well people live. There are genes that predispose to diseases and genes that predispose to healthy living, as well as genes for personality, coping strategies, and resilience.
At the same time, I think we are not necessarily slaves to our genes. Many people say that to live a long and healthy life, choose your parents wisely. That's not exactly true. Studies have shown that less than 50% of longevity is accounted for by genetic factors. Plus, environment and behavior have a significant impact on the expression of genes. For example, 2 people may have similar genes, but one develops lung cancer because he smoked, while the other one does not.
Another interesting concept emerging from the literature is neuroplasticity of aging. There are some studies showing that the brain can continue to grow or develop even in old age. In other words, neuronal regeneration can occur, under certain circumstances, as we age. It has been shown in animals, for example, that a stimulating environment facilitates regeneration of neurons in our brains. Just that suggests that [a stimulating environment] might facilitate neuroplasticity of aging and, thereby, successful aging.
Medscape: Can you give a few examples of people who have aged successfully?
Dr. Jeste: Franklin Roosevelt was a great example of somebody with a physical disability -- in a wheelchair most of his life -- who was amazingly successful. Another example is the story of an 83-year-old man named Frank White, published in The Los Angeles Times earlier this year. Until the age of 68, he was aging unsuccessfully. He had severe diabetes, hypertension, and arthritis. He was an alcohol abuser and a dependent person. It looked like his life was going downhill. At 68, he had a turning point and decided to change his lifestyle. He stopped drinking, and took to yoga. (This is not an ad for yoga, but yoga can be more than physical exercise.) Frank became so good at yoga that now he has become one of the most acclaimed yoga teachers in Hollywood, which is a feat, given the numbers of yoga teachers in Hollywood. He still has diabetes and hypertension, but they are under much better control. He is a prime example of how you can take control of your life and change it.
I don't mean to be simplistic, however. Not everybody can make such changes. Many people have serious physical illnesses over which they have no control and, in spite of the best treatment available, cannot do much. Again, I don't want these points to sound naive. The main message is that there are things within one's control, and certain changes canimpact one's physical health, even though they don't determine one's physical health.
Medscape: Along these lines, can you talk about physical exercise and its impact on mood and successful aging? For instance, isn't there research suggesting walking on a regular basis instead of going to therapy or in addition to going to therapy is a great mood enhancer?
Dr. Jeste: There have been some great studies in mice and in dogs showing that exercise not only improves physical function but also brain function. In other words, it is not merely improvement in mood -- I mean, it's hard to assess a mood in mice, right? But their neuronal function improves.
There have been several well-controlled studies in people as well that show that physical exercise not only improves mood, but also improves cognitive function. There are studies showing that exercising during your 50s is associated with better functioning when in your 60s. Exercise need not be strenuous exercise; you don't have to climb mountains or anything like that. Just improving your level of physical activity on a consistent basis has a positive impact.
Medscape: Would you say, then, that physical activity is essential for successful aging.
Dr. Jeste: Physical activity is one key element for successful aging, but mental activity is essential as well. You must keep your mind active by reading, writing, attending classes, etc. Aging is often associated with retirement, but that should not mean retirement from learning new things. There is a certain myth that you can't teach an old dog new tricks. In fact, that's totally wrong. Even Freud said something along these lines that was wrong. He said that people over the age of 50 don't have the capacity to learn new things, suggesting that doing any kind of reconstructive therapy in old people is a waste of time. Of course, he was talking about classic psychoanalysis, which may be different, but old people can learn new things. Not only that, people who try to learn new things, actively engaging their minds in the process, are much more likely to age successfully than those who do not.
Medscape: Is there anything you would like to add?
Dr. Jeste: Well, in my opinion, successful aging should be considered a neuropsychiatric entity and, as such, of particular interest to mental health clinicians. To date, we have not been involved enough; I think that should change.
Also, the typical attitude toward aging is quite negative. When we read in the papers about the population growing older, there is a sense of gloom and doom about how much we are going to spend on healthcare and Social Security. As a culture, we need to look at the positive sides of aging; aging can be associated with continued productivity, learning of new things, and better contributions to the society. There are things that old people can do through their wisdom and experience that would not be possible for those who are younger.
Medscape: Thank you very much for sharing your insights and for ending on such an optimistic, positive note.
UCSD. 2005;10(2) © 2005 University of California, San Diego, School of Medicine
Cite this: Secrets of Successful Aging: An Expert Interview With Dilip Jeste, MD - Medscape - Sep 21, 2005.