10/19/2015 – Keynote Address:  Laura Carstensen, Ph.D.
25
August

By Adem Lewis / in , , , , , , , , /


Thank you, Dr. Reece. It is an honor to be
here with you this morning as we begin a day considering these added years that we have
been granted. One thing is very clear, we are living in an era where people are living
longer than our grandparents, our great grandparents ever could have dreamed. And let me say that
members of the National Academies, this elite body, are special in many ways. Reasoning
from the research literature, I can also tell you that the vast majority of you are going
to live to very advanced ages. You’re going to sail past 80, see your 90’s, and lots of
you are going to live to be 100. And your children, your grandchildren, well one prominent
demographer in Germany recently estimated that about half of the babies born since 2000
will live to 100 and beyond. In the 20th Century life expectancy in industrialized
nations around the world nearly doubled. And I know you know these statistics, but, make
no mistake, this is a change that is unprecedented in the history of humankind. More years were
added to average life expectancy in the last century than all of the increases across all
prior millennia of human evolution combined. So, in historical terms, in a blink of an
eye we nearly doubled the length of the lives that we are living. We don’t know for sure what life expectancy
was as our ancestors were evolving in the African savannah, but the estimates range
from 18 to 20. Life was short. You know, think about it for a minute. You know, you have
to grow old enough to be able to reproduce, and then hang around long enough for your
offspring to be able to grow old enough to reproduce. So it was touch and go for the
species throughout much of our history. Evolution acted on age, especially in these early years.
It acted in the way that evolution acts, at a snail-like pace. And life expectancy got
a little bit longer, a little bit longer, a little bit longer. By the mid-1800’s life expectancy in the U.S.
had reached the mid-30s. By 1900, it was 47. And then by the end of that same century life
expectancy was 77. Today, it’s 79, and this change is not finished with us yet. In recent
years, three months has been added to average life expectancy at 65 every year. And because
fertility rates dropped by half across the very same years that life expectancy increased
so dramatically, we have now aging societies. We could have just had a larger population
of long-lived people had we not also seen this decline in fertility. But now we see
age redistributed in societies in very important and dramatic ways. In 1900, about 4% of the population in the
United States was over 65. Today, it’s 14%. And by 2030 it will go to 20%. And we are
the young kid on the block compared to our friends in Western Europe and parts of Asia
where this proportional change is much greater. Today, 23% of the population in Japan is over
65. And projections range from 35% to 40% for 2050. These are stunning changes in the
population. Well, so far, the reigning champ of longevity
is a woman named Jeanne Louise Calment, a French woman. She holds the title of the longest-lived
person ever. She died in 1997 at the age of 122. And so we know that lifespan capacity
has to be at least 122. She’s already made it. And I like to tell stories about her whenever
I get a chance because she was a wonderful character. She’d met Van Gogh when she was
a teenager, and so she played herself in the movie “Vincent and Me” at the age of 114,
which made her the oldest actress of all time. She was known for her sharp wit to the end.
A journalist interviewed her when she was 120 and asked her what sort of a future she
envisioned. Calment paused and said, “A very short one.” But my favorite story about Calment, hands
down, is one about a property deal that she made at the ripe old age of 90. She lived
in her own home, the family home, in the French city of Arles. And she had every intention
of living there for her entire life, until she died. But there was this young lawyer,
this 47-year-old lawyer, and he really wanted to buy the house. So he would make her an
offer. And she would say no. And he would go away, and then come back later and make
her a better offer. And this went on for some time. At one point, he appears on her doorstep
and he says, “I have a proposition for you, I will pay you $400 a month for the rest of
your life if you will deed the house to me on your death.” So she thinks about it and
she says okay and a contract is drawn up. And over the next 30 years he pays her more
than three times the value of her home. In the end, she outlived him by two years. He
died at 77. But they had become friends over the years and he attended her 120th birthday
party shortly before he died. And they were overheard talking and word has it that she
had turned to him at one point and said, “Look, we all make bad deals.”
That’s what 122 can look like. Well how long can we live? What is lifespan
capacity? The answer to this question is unknown. And the topic is a subject of considerable
debate. You know, ever since we humans understood our own mortality, we have been searching
for a fountain of youth. We used to sail off in ships. Now we turn to laboratories. And
today you will hear from very serious scientists who believe that scientific advances in the
21st Century may lead to an increase in lifespan, the capacity of life. But what we also know is that increasing lifespan
capacity had nothing to do with the increases in life expectancy that we are living through
today. To our knowledge, we are hardly different genetically from our ancestors 10,000 years
ago. Rather, the story of how we, as a society, somehow launched ourselves into this era of
long life doesn’t really begin with a discussion about older people. It begins with a story
about babies. The dramatic increase in life expectancy, the average length of life, came
about largely because fewer of the youngsters died. In 1900, 25% of babies born in the United
States died before they reached five. Many more died before they reached 12. Maternal
mortality was very high. And, in fact, death was not associated strongly with age because
people would become sick and die at all ages. So life expectancy in the last century increased
greatly from saving the lives of the little ones. Well how did this happen? In a word, culture.
By culture I don’t mean only the languages we speak and the foods that eat, but the crucible
that holds science and technology and broad scale social norms and behavioral practices.
We built a world to protect the young. We, I should say, you discovered the causes of
many diseases and the ways that they were spread. We developed public health programs
to inoculate young ones against diseases they would never have to suffer. We didn’t stop
there. We pasteurized milk and purified waterways. We implemented the systematic collection of
waste, garbage collection. And there are historians who write that you have your garbage collectors
to thank as much as your physicians for this increase in life expectancy. Scientists discovered the nutritional needs
of young children, and in a matter of decades, about 20 years, food fortification programs
in United States and Europe built vitamins into the food supply that virtually eliminated
conditions like rickets and other nutritional disorders. We didn’t stop there. As fertility
rates fell dramatically, we came, as a society, to invest more in children and put public
education in place in every state in this great nation so that all children, not just
the privileged few, could learn how to read and write. Agricultural technologies led to
a steady food supply throughout the year. The discovery of electricity meant that not
only electricity but refrigeration was made available in virtually every American household.
And imagine how the safety of the food supply improved with refrigeration in the entire
population. In other words, we built a world explicitly designed to support young life. Today, it’s not just from birth. We begin
to care for young ones before they’re even born. Think prenatal vitamins and care. Think
Mozart played at belly height. And now this population pyramid that we learned about in
school is being transformed into a rectangle. And if you’re the kind of person who can get
chills from biostatistics, my people, these are the ones that should do it because what
this means is that for the first time in history the vast majority of babies born in the developed
world are having the opportunity to grow old. This is a stunning achievement. And so here we are, standing at a point in
history where for the first time people in the Western world can anticipate living to
old age, and where we will see four, five, and conceivably six generations alive at the
same time. You know, we often hear people say back in the old days all the generations
lived together on the family farm. Not really. Occasionally, but mortality prevented that.
A 20-year-old male today has a better chance of having a living grandmother than a 20-year-old
in 1900 had of having a living mother. That’s what these changes have done. And this is
a game changer. It will change every aspect of life as we know it, work, retirement, the
nature of family, education, politics, all of these aspects, these fundamental aspects
of life will change. I’ve had the privilege of serving in a MacArthur
Network on Aging Societies in the past recent years that’s led by Jack Rowe. And we have
been considering how aging societies can be high quality societies, and perhaps, again,
how aging societies could improve even more the welfare of young children. You will hear
more from him this afternoon. But, interestingly, even though we’ve been given this gift of
life, 30 extra years, where you think we might be out dancing in the streets, you know, cheering
on, “Yay, we’re going to live for a long time,” we’re not seeing that at all. Policymakers
are concerned about the sustainability of policies, and individuals are concerned about
their own futures. Why? Well I don’t have a lot of time with
you today, and so I thought I would summarize the research literature in one slide. You
can put anything you like on the Y-axis. This has been the premise, I think, of most research
on aging. And I would like to tell you that there’s really no support for this model.
But, in fact, there’s a lot of evidence for many problems that occur with age. At the
same time, the more we learn about aging, the more nuanced that story becomes. It is
clear at this point that the steady downward trajectory does not characterize aging necessarily. And, in fact, there’s a lot of good news.
Every generation over the last 50 years, every birth cohort that has arrived at old age has
been healthier than the one before it. And today there is some evidence that this progress
may have paused and may even reverse, but there is no question that the elderly today
are functioning better than the elderly 50 years ago. By and large, older people today
are emotionally stable, knowledgeable, and, among the educated, are faring very well. Let me show you some findings that are quiet
reassuring. This is a slide produced by my colleague, John Shoven at Stanford, an economist.
And what you’re seeing here is not age on the X-axis but historical time. And what you’re
seeing in these lines is the age where mortality risk reaches different levels. So, in black,
you see the age where mortality risk gets to 1%, 2%, 4%. What Shoven argues is that
when your mortality risk reaches 2%; that is, in the next year you have a 2% chance
of dying, we’ll call you old. And what he says is that we’ve been measuring age wrong
because we’ve been measuring it as the number of years since you were born, and a better
way to think about it may be the number of years you have left. And you know how people like to say 60 is
the new 40? Well 65 really is the new 59 by this measure. So if we look at 1970 — this
is for men but women’s’ trajectories are highly similar — a man reached that mortality risk
point at 59. In 2000, it was 65. Now, Jim Vaupel, a demographer, says that in 2014 these
findings are even more striking, that 70 is the new 60. So what we’re seeing is this indication
of impairment of illness being pushed out farther into the future. Demographers were
very nervous early on when they saw just how big this change was, that what we had done
was to create longer and longer periods of disability. And instead it looks like we haven’t
reduced those periods of disability very well, but we have pushed them out to the future.
So the added years of life expectancy in adulthood are largely healthy ones. Arguably, even more important is functional
health. And these are findings from a recent study published in the Journal of Gerontology.
This is self-reported functional health, asking people at different ages whether they are
healthy enough to do housework, whether they are healthy enough to work. And what you see
is that the majority of people, even in the 85+ age group, report that they are functionally
health enough to work. Now, what you also see in this study, and in the literature at-large,
is that what does change is the variability that we see in functioning at increasingly
older age groups. And this variability in functioning is not random. What you see here are the proportion of people
with no functional limitations at different ages. This is a study published by Jim House.
And at 30, regardless of education level — so in red you’re seeing people with college education,
little education in blue, and less than a high school education in green — at 30, they’re
functionally healthy regardless of education. And if we go to the very end of life, people
over 85, we begin to see functional health converge again. This, very likely, reflects
mortality and illness just prior to the end of life. But in the middle we see dramatic
differences by education level. And we don’t fully understand what education does, but
it clearly predicts optimal aging. The story about cognition is not quite so
cheery, but we’re also learning more about that. This is what we have seen in study after
study, longitudinal data, cross-sectional data that processing speed, the ability to
take in new information and act on it declines gradually across adulthood. What we hear less
about, however, is that across the same years, knowledge is increasing. So people know more,
even if they’re not as quick in generating responses to brand new, novel information.
And this estimate of knowledge really has to be grossly underestimated because the tests
of knowledge are general knowledge, you know, “What is the Afghanistan?” It’s not — they’re
not questions about deep expertise, which also seems to improve. And there have been two new studies published
recently supported by the National Institute on Aging that, to me, may be really turning
on its head this idea that we see gradual decline in cognitive processing with age.
This is a slide from an article published by David Bennett and his group. And they followed
people over time, a large group of older people, over a decade. And what they find is that
some of the people they were following go on to develop Alzheimer’s disease, others
never do. And what you see in the blue line is the cognitive functioning over that ten-year
period of people who were in prodromal stages of Alzheimer’s disease, they were going to
go on and develop it. To me, the really exciting part of this is
when you look at the cognitive decline in those people who did not develop Alzheimer’s
disease. And if there’s any good news about Alzheimer’s disease, and there is not much,
it’s that most people won’t get it. And so I think this also is telling us, as are these
other studies, that a reliance on statistical means as the primary way to describe aging
and to think about what it means may be conflating illness with aging. And the story about emotion, emotional experience,
and stability is really good. If it surprises you, you’re not alone. It makes headlines.
But older people report better emotional experience in day-to-day life. They’re better able to
regulate strong emotions, better able to solve emotionally-charged problems, and slower to
anger, more likely to forgive, more appreciative, more grateful about life. We must not fail
to tap a growing resource, maybe the only natural resource in the world that’s actually
growing, older people, who are knowledgeable, healthy, emotionally stable, and even-handed.
We need to build an infrastructure that taps older citizens. Of course, it’s hardly time to rest on our
laurels. There are a raft of diseases, not new but new in terms of their impact on society,
that are associated with aging, and we need now to invest in finding cures and finding
ways to prevent them from developing. We need a cure for Alzheimer’s disease. We need to
find ways to prevent osteoarthritis, osteoporosis, stroke, cardiovascular disease. Age is a risk
factor for most diseases. And in a society that is aging, we need to find ways to address
them. Human need, we say, is the basis for virtually
all of science. Science helped get us here, and we need science today more than we ever
have so that we can move forward with new advances that keep the population healthy.
And today maybe the best news of all is that the potential of science is breathtaking.
Biologists are finding ways to rejuvenate stem cells. This is an — there’s an approach called parabiosis.
My colleague, Tom Rando at Stanford, has been working in this area with muscle tissue. And
for many years people believed that muscle tissue could not repair as well as in younger
organisms because of some deficiency in the stem cell itself. With parabiosis, attaching
the blood supply of a young animal to an old animal, Tom and his colleagues have shown
that the stem cell activity, this is what you’re seeing in young and old animals, and
then — whoops, sorry — after attaching this blood of the old animal to the young, we see
this rejuvenation of stem cell activity and muscle repair. This has been shown now in
liver, in brain, and hear tissue. You’ll hear more from the biologists shortly. But these
kinds of findings on the biology of aging, suggesting that there may be ways to improve
healthy and to keep us healthy over time are remarkable. Technologies will come to help us function,
despite problems. And we are seeing many new technologies emerge. There are sensor technologies
that can be placed in homes that maintain privacy, just a few sensors in a home that
can monitor activity and let loved ones or other individuals know if there is a change
in activity. A colleague of mine, Tom Andriacchi, has developed a shoe that slows the progression
of osteoarthritis. Wearable devices like this will be coming on the market. And bioskin,
these very, very thin sensors that will be wearable and wirelessly allow for the monitoring
of different kinds of health conditions. And, in some cases, also the treatment of those
conditions is being developed and is very exciting. These bioskins will be ten times
thinner than Saran wrap, that kitchen wrap that we’ll wear or have tattooed on us that
can monitor health states. We’re beginning to make a little bit of progress
with obesity. Just as we need to turn to the laboratory and support research on basic cures
and biology, we need to find ways to change the way we live. In long-lived populations,
solving problems will mean changing behavior. Today, more than a third of adults and 17%
of youth are obese, and we must turn this around. We’re beginning to make progress on
understanding the nutritional needs of young children. And we need to find out more about
this, about individualized medicine, but also individualized nutritional needs so that we
understand what kinds of diets are best for people at different ages, and be able to counsel
people on ways that diet must change. When we think about health in an ear of longevity,
it will not be about older people alone. We need to get younger people engaged in activities
and exercise with habits that begin early in life and continue all the way through.
High impact exercise, especially in girls, may help to prevent osteoporosis. And we have
to develop new norms so that these exercise practices never stop. Exercise today may be
the best preventive practice around, including competing with other kinds of medications.
Geriatricians I know say that if we could put exercise in pill form it would be the
most sought after drug on the market. We’re learning that behavior influences health
in other ways. Engaging in emotionally meaningful contributions to society appears to have as
big health consequences, benefits, as smoking cessation. If Linda Fried has her way, public
health recommendations in the future will be get a flu shot and go volunteer. And as
research accumulates, it also appears that work, paid or unpaid, may improve cognitive
functioning. We have known for a long time that people in the workforce are better physically
and cognitively than people who are out of the workforce, but selection effects have
prevented a deep understanding of this. In a comparison of countries by the generosity
of the pension programs, Bob Willis and Rohwedder have shown that cognitive functioning in a
population in countries where pension policies are less generous perform better cognitively
than in countries — I won’t say anything here, but — in countries where people retire
early. You already saw a slide of this book, Dr.
Dzau. In an age where people are coming to live out their full lives, it is time, it
is essential that we come to terms with death. You know, medicine was born in an era where
the vast majority of people died prematurely. Today, aggressive medical treatment at the
end of life tops the list of the greatest fears of older people. My colleague, Phil
Pizzo, and former comptroller David Walker, chaired this report, and already, as you’ve
heard, this is having a big effect on policies and programs and approaches. And member Atul
Gawande’s book, “Being Mortal,” has done just a tremendous service for the nation. Writing
a book on dying and making the New York Times Bestseller List is really an accomplishment.
But he has so beautifully crafted the situation and the arguments that people are beginning
to engage in these conversations. We have the opportunity to live long and to die well. More and more we see that this is possible.
And, indeed, in the end, the problem may not be aging at all. The problem may have much
more to do with inequality. I mentioned the MacArthur Network on Aging Societies. Another
network, chaired by Nancy Adler, on inequality came to similar conclusions. Both of these
networks, both on socioeconomic status, one on longevity, concluded that the cumulative
effects of disadvantage on health present a challenge that we must address. To fully
reach the potential that longevity affords we must acquire a deep understanding of disadvantage
and we must develop bold, lifelong interventions and investments in the entire population. Disadvantage has effects early in life on
children. You see here the prevalence of health problems by socioeconomic status from asthma,
ear diseases, injury, physical inactivity. We’re seeing this very early in life. And
socioeconomic status, education puts people on tracks where they enter workplaces, where
they don’t have health insurance, their shift work, long working hours, family conflicts,
low job control, job insecurity, and by some accounts this may account for about 20% to
40% of the differences in life expectancy. Here you see that it’s not just quality of
life that is affected by disadvantage, the very length of life is predicted by family
income. The greatest threat to failure in realizing
the potential of aging societies is setting the bar too low. It will be assuming that
aging is synonymous with decline. It will be a failure to recognize that pediatrics
is as important as geriatrics in long-lived societies. It will be a failure to make physical
exercise something that begins early and lasts all the way through. It will be a failure
to tap the resource that older people represent. It will be a failure to recognize that a growing
population of even-handed, emotionally stable people can address some of the greatest problems
in the world today. We can make aging societies the best thing that ever happened to children
and families. Longevity is giving us the opportunity for the first time ever to fully redesign
life so that added years of life can improved quality of life at all ages. We must not waste
this gift of long life. Thank you.


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