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How
do you define a healthy 80-something? By
Scott LaFee UNION-TRIBUNE
April
9, 2003
Today,
an estimated 5,574 Americans will celebrate their 65th birthday. That's
362,310 candles, if you're counting. Traditionally,
reaching age 65 has marked a sort of endpoint. But while that might apply
to many careers, it's far from true about life. Americans are living
longer than ever. At age 65, the average American can expect to see at
least one more generation mature. According to IRS mortality tables,
there's a 5 percent chance he or she will even reach 100.
Not
great odds perhaps, but the numbers are compelling. There are roughly
70,000 centenarians living in the United States today. In 50 years, there
will be more than 800,000, according to population projections. That's
almost double the current total population of Wyoming. Such
longevity presents questions and challenges well beyond finding enough
candles. What does it take to live a long life? Are aging and decline
inextricably linked? What does healthy mean when you're 80 years old? "Just
as children are not small adults, older people are not simply older
adults," said Dr. Dilip Jeste, chief of geriatric psychiatry at UCSD.
"They are different due to changes in biology, psychosocial changes,
the accumulation of life experience, not to mention diseases common to the
aging process." In
some ways, doctors and medical researchers are just beginning to fully
appreciate these differences. Gerontology – the study of aging and old
age – and geriatric medicine are comparatively new endeavors, said Dr.
Dennis Carson, director of the Stein Institute for Research on Aging at
UCSD. "Up
until probably this decade, doctors didn't get much opportunity to see
normal aging. Most people died from specific diseases," said Carson.
"Now we can treat and often prevent many diseases, which means we're
getting a better look at what it means to be an octogenarian and older.
Still, at the moment, nobody has a complete understanding of what aging
means in humans." To
be sure, aging means death – eventually. By most estimates, the maximum
human life span is somewhere around 120 years. Jeanne Calment, a French
woman who died in 1997, represents the oldest documented life. She lived
to be 122.
But
far less certain is the connection between aging and disability. "We
all die from something," said Carson, "but there are a lot of
very old people who are as smart as ever, who jog, play tennis, do what
they've done all their lives. Aging brings general decline, but no one yet
can define how much, or what's normal." Norton
Davey is proof of Carson's point. Davey is an Oceanside triathlete. Four
years ago, he competed in an Ironman triathlon in Florida (2.4-mile swim,
112-mile bike ride, 26.2-mile run). Davey finished the race, but was
declared an unofficial competitor because he took longer than the maximum
17 hours. Davey finished in 18 hours. He was 80 years old at the time. "I
got interested in triathloning in my mid-50s, after my company's medical
director said he thought I needed some exercise. I had a pretty sedentary
life at the time, a desk job," said Davey, now 84. "Obviously,
the exercise has done some good." Davey,
of course, is an exceptional case. Few people in their 80s can reasonably
expect to run, swim and bike daily without suffering unwanted
consequences. Most Americans really aren't interested in how fast they can
run a mile, but they do want to know what it means to be elderly and in
normal health. These
days, life expectancy at birth is almost 80 years for women, 74 years for
men. The population of older Americans, based on the 2000 U.S. census,
stands at approximately 35 million. In less than 30 years, it is projected
to double, swelled primarily by elderly baby boomers. But
it is the ranks of oldest Americans that are growing fastest of all. In
1900, there were just 122,000 Americans 85 years or older, a figure less
than the current total population of Escondido. In
2000, however, the number of Americans age 85 and older exceeded 4.2
million, and it is projected to reach 8.9 million by 2030. This total
would exceed the current combined populations of Vermont, Maine, Idaho,
Hawaii, Delaware, Montana, New Mexico, South Dakota and Alaska. Decline
vs. disease
In some ways, medically speaking, it's harder than ever to tell the
difference between young and old. For example, doctors once presumed blood
pressure inherently climbed with age. Hypertension was inevitable. Now,
they're not so sure. "Blood
pressure in a healthy older person shouldn't be much different than that
in a young person," said Dr. Joe Ramsdell, head of UCSD's division of
internal medicine and geriatrics. The same holds true for most basic blood
tests, such as cholesterol levels. Indeed,
the real culprit in hypertension or elevated cholesterol for many people
is behavior and lifestyle. "It's related to living a long time in a
Western, urbanized lifestyle," said Dr. Elizabeth Barrett-Connor of
UCSD's Family and Preventive Medicine program. "It's excesses in
food, the amounts eaten and underexercising." Some
standards of health in the elderly simply don't yet exist. There isn't
enough data, for example, to categorize pulmonary function, according to
Ramsdell. What's healthy for one person may not be for another. It all
depends upon individual factors, such as diet, lifestyle, genetics and
other health factors. One
major rule of thumb in deciding what is normal, successful aging and what
is not, said Ramsdell, is the rapidity of physical change. The effects of
normal aging don't happen overnight. "If
somebody suddenly starts complaining of shortness of breath, that's
probably not due to normal aging, which tends to be felt gradually and is
most often related to diminishing, limited reserves." For
example, a 70-year-old who has exercised regularly likely boasts the same
lung capacity as a 20-year-old who does not exercise regularly. "A
lot of decline is influenced by activity," said Ramsdell.
"Staying active can keep the body working well for a very long
time." The
same advice applies to cognitive function. Neuroscientists once thought
that the human brain, after childhood, was essentially doomed to lifelong
decline. A child began life with a maximum number of neurons and, over
time, many of these cells died. They were not replaced. Eventually, neuron
loss tipped the scales toward dysfunction, disease and dementia. But
that's no longer believed to be true. "The good news is that there's
very little death in the early to middle stages of aging in the
brain," said Dr. Mark Tuszynski, a neurologist and neuroscientist at
UCSD. Mental
abilities may diminish with age – increasing bouts of mild forgetfulness
or memory loss, for example – but many neuroscientists now suspect the
cause is linked to changes in the brain's biochemistry. "The
best guess is some decline of expression in some genes that correlates
with some loss of function," said Tuszynski. For
example, in studies of aged rats with impaired cognitive function,
researchers found that certain cell pathways no longer recognized or
reacted to key neurotransmitters, such as growth factors. On the other
hand, other rat studies indicate that older brains learn to compensate for
age-connected impairments. "The
emerging picture is that the brain is much more dynamic than once thought.
Connections are actively changing, turning over," Tuszynski said.
"The way we learn things or record experiences is through actual
change in the receptors of cells and the literal structure of the brain. "Animals
exposed to an enriched environment show better, improved cognitive
function than those who do not. It's no doubt true of humans, too. Staying
engaged in life, mentally active, keeps the brain young. The idea that one
ought to (mentally) slow down with age is 180 degrees wrong." The
growing number of older Americans poses particular problems for
psychiatrists and psychologists. To wit: There are simply more mentally
ill people over the age of 65. In fact, the rate appears to be increasing
disproportionate to population growth. In
a 1999 paper published in Archives of General Psychiatry by
Jeste and colleagues, the number of Americans older than 65 with
psychiatric disorders was projected to grow to 15 million in 2030 from
about 4 million in 1970. Jeste
cited a couple of likely causes: More
people with serious mental illnesses were living longer. "It
used to be that many of these patients died young. Ten to 15 percent of
schizophrenics committed suicide. But as better treatments have emerged,
more mentally ill are reaching old age," Jeste said. Aging
baby boomers appear to be at higher risk of developing depression and
substance abuse than previous generations. Jeste conceded that the reasons
why aren't clear. "There's
possibly some sort of biological explanation, but it could also be
psychosocial. Families after World War II were smaller and more mobile.
Divorce rates rose. There were more broken families, more
disconnectedness. Gender roles changed. And baby boomers are more
accepting of mental illness. It's more OK to admit to depression." Everyone
at one time or another, said Jeste, gets depressed about aging. It's a
normal part of growing old, learning to accept and adapt to changing
levels of vitality or ability. The
challenge for mental-health experts is differentiating between temporary
melancholy and clinical depression. "Many of the symptoms of
depression – difficulty sleeping, loss of appetite – are also signs of
normal aging," Jeste said. "It's critical, though, to discern
which is which because depression in older people can be especially
devastating. The risk of suicide increases with age, especially among
white males. It's five to 10 times greater than in younger men." For
a lot of older people, despair begins with the measurable decline of
mental abilities. Jeste says the picture is rarely as bleak as people
think. Some decline is normal and inevitable, particularly after age 80,
but like Tuszynski, Jeste said the human brain seems to possess a
remarkable ability to compensate, if given the chance. And
some mental diseases actually appear to diminish with age. The symptoms of
schizophrenia, for example, appear to ease in persons after the age of 50,
possibly due to dropping levels of dopamine, a brain chemical. "Sigmund
Freud wrote in 1924 that people over the age of 50 were no longer
educable. They weren't worth trying psychotherapy," said Jeste.
"New research shows Freud was wrong. Older test animals that learn
new things actually show better functioning. Increased brain activity
promotes efficiency, the regeneration of neurons. This isn't just
feel-good science. The notion that old age equals mental decline is really
being challenged." The
old standard There
are multiple theories, from the notion that inevitable cellular repairs
become sloppier and less effective over time to the idea that genetics
dictates how many times a human cell will be able to divide and live
before it finally wears out and dies. It's
a complicated question. Only less daunting is defining a healthy
80-year-old. After age 75, the typical older person suffers from three
chronic medical conditions and regularly uses about five prescription
drugs. Their bodies work differently. Metabolisms have slowed. Some bodily
functions are likely to be restricted or less efficient than in youth. Doctors
expect to see some degree of decline in all elderly patients. It's
unavoidable. Disease is a different matter. "Our
ability to diagnose and treat some major diseases has really
improved," said Barrett-Connor. "Fifty years ago, we would have
said hypertension was just part of getting old. Now we understand that
it's a real disease and it can be treated." One
result is that living to old age increasingly emphasizes the living.
"A
big issue has been when do you treat a disease," said Carson at the
Stein Institute for Research on Aging. "In the past, doctors balked
at doing certain procedures or treatments after a certain age. Not as much
now. People are getting coronary bypasses and hip replacements in their
90s. They're still quite functional, with years ahead of them." Perhaps
the question, some time in the future, won't be what constitutes a robust
80-year-old, but how healthy is healthy at age 100? Copyright
© 2002 Global Action on Aging
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