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Centenarian Anna Morgan's lifelong charisma, vitality and
intelligence shone through at age 101.
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Population Genetics
We are carefully analyzing the pedigrees of centenarians to
determine if extreme longevity is more prevalent among these
families. If this turns out to be the case than such findings
would strengthen the argument that genes play an important
role in rates of aging and diseases associated with aging.
Collaborators include Jan Vijg Ph.D. at the Harvard Institute
of Medicine,CarrieWager Ph.D.at the Harvard School of Public
Health, Laura Alpert MPH and Leonid Krugliak PhD, at the Whitehead
Institute.
Studies of centenarian pedigrees led to our findings with
co-investigator, Ruth Fretts M.D. (Instructor at Harvard Medical
School and Obstetrician-Gynecologist at Beth Israel Deaconess
Medical Center) that middle aged mothers live longer. Essentially,
we found that centenarian women were four times more likely
to have had children while in their forties compared to women
who lived only to their early seventies. A woman's ability
to naturally have children (that is, without the help of fertility
experts) in her forties probably means her reproductive system
is aging slowly and therefore the rest of her is as well.
This would be predictive of one's ability to reach extreme
old age. This work was reported September 12, 1997 in Nature.
See our background section for the full text.
From the Beth Israel Deaconess Medical Center's News Release:
Centenarian Siblings
Increase Your Life Expectancy
Boston, MA -- If your
brother or sister lived to 100 years you have a 4 or 5-times
greater chance of surviving to age 90, than if your sibling
died in their seventies, supporting a link between the ability
to achieve extreme old age and how prevalent it is in your
family,say Beth Israel Deaconess Medical Center scientists
in the May 23 The Lancet. Female siblings of centenarians
survived to a median age of 80 and males to 76, whereas male
and female siblings of 73-year-olds only survived to a median
age of 74 - the average life expectancy.
The authors showed
that having a centenarian sibling increases one's chances
of surviving to very old age, indicating a strong familial
component to longevity. "If you know you have longevity in
your family you can relax a bit" says gerontologist and lead
author Thomas Perls. "If there's not longevity in your family
it's a wake-up call." It may be more important for people
in this category to beware of lifestyle choices that decrease
longevity such as smoking, obesity, lack of exercise, and
lack of regular checkups with a physician, he says.
Perls, head of the
New England Centenarian Study, and his colleagues studied
families of ten centenarian men and 92 centenarian women living
in the Eastern Massachusetts area. They compared survival
of the centenarians' siblings with siblings of 28 men and
49 women who were born in 1896 and died at 73 years of age.
Comparing people born in approximately the same year as the
centenarians controlled for factors affecting survival such
as W.W.I, the 1919 influenza epidemic, and the Great Depression,
that may have otherwise confounded the results.
Survival rates for
the two sibling groups were the same at younger ages, but
after age 70 the centenarians' siblings had an increasing
survival advantage. Female siblings of centenarians were 4
times as likely to reach age 90-94, and male siblings were
5 times as likely. The survival advantage appeared to continue
increasing beyond age 90-94.
The results further
support emerging research suggesting a link between genetics
and longevity. By focusing on survival to extreme old age,
the authors say their study is most likely to detect a genetic
effect if familial factors play a greater role with increasing
age, a finding never proven before, until now.
The centenarians in
the study also had more siblings than the 73 year olds. The
authors speculate that there may be more children in these
families because there is an associated ability to have children
later in life and therefore to have more of them. This theory
is supported by recent research from Perls's group showing
that female centenarians were more likely to have had children
beyond age 40 compared with women who died at the age of 73
years.
This study was funded
by the Alzheimer's Association, the Andrus Foundation, the
National Institute on Aging, and the Paul Beeson Physician
Faculty Scholars in Aging Research Program.
The implications of the finding that extreme old age does
run in families are significant.
A lot of people don't know that the scientific conventional
wisdom is that the heritability of longevity is low. The problem
is that studies in the past, primarily of twins, have been
based upon people only reaching, at the most, their early
eighties. Our finding that siblings of centenarians
live longer supports the assertion that the ability to
achieve extreme old age requires a genetic advantage relative
to people who survive only to their mid to late eighties.
These findings help open the door for the search for genes
in humans which affect rates of aging and susceptibility to
diseases associated with aging.
These findings help people realize that if members of their
families generally die at average life expectancy or younger
they need to take this as a warning. They really do need to
practice good health habits and see their doctor for screening
against cancers, high blood pressure and other age-related
illnesses.
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Scientific
American
The Oldest Old
People in
their late nineties or older are often healthier and more robust
than those 20 years younger. Traditional views of aging may need
rethinking.
January 1995 Volume 272 Number 1 Pages 70-75
By Thomas
T. Perls
In medical school I was taught that the incidence of chronic,
disabling disorders, particularly Alzheimer's disease, increases
inexorably with age. I therefore expected that people older than
95 years, often called the oldest old, would be my most debilitated
patients. Yet when I became a fellow in geriatrics, I was surprised
to find that the oldest old were often the most healthy and agile
of the senior people under my care. In fact, the morning I was scheduled
to interview a 100-year-old man as part of a research project, he
told me I would have to delay my visit. He had seen 19 American
presidents take office, and he would be busy that morning voting
for the next one.
Such encounters
made me wonder if the prevailing view of aging as advancing infirmity
was partly wrong. Could it be that many people in their upper nineties
enjoy good health and that the oldest old constitute a special--and
long-misunderstood--population? Since then, the centenarians I have
met have, with few exceptions, reported that their nineties were
essentially problem free. As nonagenarians, many were employed,
sexually active and enjoyed the outdoors and the arts. They basically
carried on as if age were not an issue. And accumulating evidence
indicates that a significant portion of the oldest old are indeed
healthier than many people in their eighties or early nineties.
The common idea that advancing age inevitably leads to extreme deterioration
does, indeed, seem to require revision.
Estimated
costs of caring for the oldest old in the future might need modification
as well. The centenarian population grew by 160 percent in the U.S.
during the 1980s. Many demographers predict that 20 million to 40
million people will be aged 85 or older in the year 2040, and 500,000
to four million will be centenarians in 2050. The economic burden
of caring for people older than 85 could be vast, especially if
a huge percentage of them need special care. Yet it may well be
that health bills for the oldest old will be lower than previously
expected.
Some of
the first evidence supporting my suspicions came from a study on
Alzheimer's disease that I conducted with my mentor, Lewis A. Lipsitz
of the Hebrew Rehabilitation Center for Aged in Boston. Surveys
have reported that this disorder devastates the mind and ultimately
kills about 40 percent of those aged 85 and older. Some investigators
believe that close to 50 percent of 90-year-olds have Alzheimer's
disease and that up to 70 percent of centenarians are affected.
Yet many of the studies on which these conclusions are based did
not include subjects older than 93 years, which casts some doubt
on these projections. In 1991 Lipsitz and I undertook a pilot study
to see if the occurrence of Alzheimer's disease at the center, a
chronic care hospital, matched the predictions for centenarians.
We found that of the 12 residents in their hundreds, only four seemed
to have Alzheimer's disease. This low figure--only 25 percent--was
particularly striking considering that residents of such facilities
are more likely to be impaired than are their counterparts in the
community.
Selective
Survival
Our finding
suggested that, at least cognitively, the oldest old were indeed
in better shape than has usually been assumed. What, we wondered,
could explain their good condition? We suspect that the answer to
this riddle is that, for whatever reason, some people are particularly
resistant to acquiring the disorders that disable and kill most
people before age 90. Because of this resistance, they not only
outlive others, they do so relatively free of infirmities. In other
words, in a kind of survival-of-the-fittest phenomenon, these individuals
seem to be selected for long-term survival because they possess
traits that enable them to avoid or delay the diseases that commonly
accompany aging.
The concept
of selective survival was applied, somewhat more narrowly, by demographers
in the 1970s to older African-American populations. Researchers
reported that although the death rates for blacks were higher than
for white Americans up to age 75, the trend reversed after that
age. Then, in what some called a crossover phenomenon, whites were
more likely to die at a given age than were their African-American
counterparts. They speculated that blacks tended to die earlier
because many of them were economically disadvantaged and had less
access to health care services. Therefore, those who survived represented
an unusually vigorous group, able to overcome obstacles that defeated
others. Their vigor, in turn, later gave them a survival advantage
over the majority of white Americans of similar age.
This selective
survival hypothesis may also clarify various other once puzzling
findings demonstrating unusually good cognitive and physical health
in the oldest old. It seems that men who survive into their late
nineties become less and less likely to develop Alzheimer's disease
with each passing year. Moreover, the average man in his late nineties
has a more intact mind than the average man in his eighties. These
patterns probably emerge because men who are susceptible to Alzheimer's
disease generally die of the condition in their eighties or early
nineties. These trends would be explained if the group of men who
reach their late nineties consist almost exclusively of individuals
who are not susceptible to Alzheimer's disease and who therefore
retain their cognitive abilities indefinitely. (Continued)
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