We may want to live forever, but who looks
about this magical transformation. These
forward to getting old? We hope we’re vigor-
are the types of questions and kinds of experi-
ous right up until the very end. Still, day-to-
ences that could stimulate a lifelong quest to
day, many of us make unhealthy choices that
explore what happens as we age.
could put our future at risk.
Since the National Institute on Aging (NIA)
From the beginning of time, people
was established at the National Institutes of
have tried to understand aging. Almost
Health (NIH) in 1974, scientists asking just
every culture has a mythology to explain it.
such questions have learned a great deal
As we grow up, tales of eternal youth pique
about the processes associated with the
our curiosity. And, it is these musings that
biology of aging. For scientists who study
may provide just the spark needed to ignite
aging—called gerontologists—this is an excit-
a budding scientist. There’s the little girl,
ing time. Technology today supports research
excited to visit her grandmother, who asks
that years ago would have seemed possible
her parents how someone so spunky and
only in a science fiction novel. And, a scientific
fun could be so old. Or, the 3rd grader who,
community that values active collaboration as
after watching in awe as a caterpillar spins
well as individual scientific achievement has
a cocoon and then days later emerges as a
helped to move research forward faster than
butterfly, peppers the teacher with questions
ever before.
BIOLOGY OF AGING: RESEARCH TODAY FOR A HEALTHIER TOMORROW 3
Over centuries, theories about aging have
literally slowed down the runners. Although
emerged and faded, but the true nature of the some physical decline may be a normal result aging process is still uncertain. The fact is—
of aging, the reasons for these changes are of
aging is a part of everyone’s life. But the facts
particular interest to gerontologists.
of aging—what is happening on a biochemi-
Gerontologists look for what distinguishes
cal, genetic, and physiological level—remain
normal aging from disease, as well as explore
rich for exploration.
why older adults are increasingly vulnerable
This booklet introduces some key areas of
to disease and disability. They also try to
research into the biology of aging. Each area
understand why these health threats take
is a part of a larger field of scientific inquiry.
a higher toll on older bodies. Since 1958,
You can look at each topic individually, or you
NIA’s Baltimore Longitudinal Study of Aging
can step back to see how they fit together in
(BLSA) has been observing and reporting on
a lattice-work, interwoven to help us better
these kinds of questions. As with any longi-
understand aging processes. Research on aging tudinal study, the BLSA repeatedly evaluates is dynamic, constantly evolving based on new
people over time rather than comparing
discoveries, and so this booklet also keeps an
a group of young people to a group of old
open eye on the future, as today’s research
people, as in a cross-sectional study. Using this
provides the strongest hints of things to come.
approach, BLSA scientists have observed, for
example, that people who have no evidence
What is aging?
of ear problems or noise-induced hearing
loss still lose some of their hearing with
In the broadest sense, aging reflects all the
age—that’s normal. Using brain scans to learn
changes that occur over the course of life.
if cognitive changes can be related to struc-
You grow. You develop. You reach maturity.
tural changes in the brain, BLSA scientists
To the young, aging is exciting—it leads to
discovered that even people who remain
later bedtimes and curfews, and more inde-
healthy and maintain good brain function
pendence. By middle age, another candle
late in life lose a significant amount of brain
seems to fill up the top of the birthday cake.
volume during normal aging.
It’s hard not to notice some harmless cosmetic
However, some changes that we have long
changes like gray hair and wrinkles. Middle
thought of as normal aging can be, in fact,
age also is the time when people begin to
the signs of a potential disease. Take, for
notice a fair amount of physical decline.
example, sudden changes in personality.
Even the most athletically fit cannot escape
A common belief is that people become
these changes. Take marathon runners, for
cranky, depressed, and withdrawn as they get
example. An NIA-funded study found that
older. But an analysis of long-term data from
their record times increased with age—aging
the BLSA showed that an adult’s personality
4
AGING UNDER THE MICROSCOPE
POSSIBLE PATHWAYS
LEADING TO AGING
SIGNALS ENTERING THE CELL
CELL
NUCLEUS