Download Life Expectancy, Aging and Centenarian research

Life Expectancy, Aging
and Centenarian research
Carolyn R. Fallahi, Ph. D.
Life Expectancy
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The definition of Life span: the maximum #
of years an individual can live.
What is the maximum? Probably 120 years.
Average Life Expectancy
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Males 74
women 80
overall 77
social factors affect when we will die.
Sex differences & longevity.
Predictors of Psychological longevity?
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1921 Louis Terman
“Termite” study
Reanalyzed by Friedman et al (1995)
Centenarians
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The number of centenarians has increased.
In 1980 there were only 15,000 centenarians.
2000 there were 77,000
Projected that by 2050, 834,000
New England Centenarian study.
Segerberg, 1982
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1,200 centenarians interviewed
What makes a difference?
Duke Longitudinal Study
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Palmore (1982)
25 year period
270 volunteers
Ages 60-94
The Nun Study
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David Snowdon
678 nuns in Minnesota
Issues: intellectual job & folic acid
Theories of Aging
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The first 3 theories that I’m going to talk
about today explain aging at a cellular level.
Theories of Aging
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Cellular Clock Theory: Leonard Hayflick
(1977) theory.
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Cells can divide a maximum number of times,
approximately 75-80 times.
As we age, our cells become less capable of
dividing.
Cellular Clock Theory
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The tips of chromosomes are called telomeres
and they are DNA sequences that cap
chromosomes.
After about 70 or 80 replications, the
telomeres are dramatically reduced and the
cell can no longer reproduce.
Free – Radical Theory
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A second microbiological theory of aging is
called the free-radical theory.
People age b/c their cells metabolize energy.
When they do this, they generate waste that
includes unstable oxygen molecules known as
free radicals.
These cells cause damage.
Mitochonrial Theory
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The role of mitochondria – tiny cellular
bodies that supply energy for function,
growth, and repair – might play in aging.
It seems that the decay of mitochondria is
primarily due to oxidative damage and loss of
critical micronutrients supplied by the cell.
Hormonal Stress Theory
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This theory explains aging not at a cellular
level, but at a hormonal level.
The hormonal stress theory – argues that
aging in the body’s hormonal system can
lower resistance to stress and increase the
likelihood of disease.
Which one is correct?
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This is anyone’s best guest.
Maybe all of them are involved.