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Life Expectancy, Life Expectancy, Aging, & Centenarian Aging, & Centenarian

ResearchResearch

Carolyn R. Fallahi, Ph. D.Carolyn R. Fallahi, Ph. D.

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How has the life span How has the life span changed?changed?

2020thth Century = 65 years old. Century = 65 years old. Definition of Life span = upper Definition of Life span = upper

boundary of life, the maximum boundary of life, the maximum number of years an individual can number of years an individual can live.live.

What is the maximum theoretically?What is the maximum theoretically?

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Average Life ExpectancyAverage Life Expectancy

MalesMales FemalesFemales What influences when we will die?What influences when we will die? Sex differences associated with Sex differences associated with

longevity.longevity.

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What are the predictors of What are the predictors of psychological longevity?psychological longevity?

Louis Terman 1921 – termite studyLouis Terman 1921 – termite study Freidman et al (1995) – analysis of Freidman et al (1995) – analysis of

the “termites”the “termites” Looked at:Looked at:

– Effects of personalityEffects of personality– Stressful life eventsStressful life events– Health-related behaviorsHealth-related behaviors

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Divided stress Divided stress

Parental divorce in childhoodParental divorce in childhood Marital instability in adulthoodMarital instability in adulthood Both were found to be good Both were found to be good

predictors of the age of death.predictors of the age of death. More explanationMore explanation

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CentenariansCentenarians

1980 = 15,0001980 = 15,000 2000 = 77,0002000 = 77,000 2050 = 834,0002050 = 834,000 Why?Why? Segerber (1982) study looking at Segerber (1982) study looking at

1,200 centenarians1,200 centenarians

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Duke Longitudinal StudyDuke Longitudinal Study

Palmore (1982)Palmore (1982) Longitudinal study over a 25 year Longitudinal study over a 25 year

periodperiod 270 volunteers270 volunteers Physical, marital, social, laboratory Physical, marital, social, laboratory

taskstasks Best predictors of longetivity?Best predictors of longetivity?

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The Nun StudyThe Nun Study

David SnowdonDavid Snowdon 678 nuns from a convent in 678 nuns from a convent in

MinnesotaMinnesota Tests included cognitive & physical Tests included cognitive & physical

functioning & they will donate their functioning & they will donate their brains upon death.brains upon death.

What did they find?What did they find?

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Theories of AgingTheories of Aging

Cellular Clock Theory: Leonard Hayflick Cellular Clock Theory: Leonard Hayflick (1977) theory.(1977) theory.– A microbiological theory of agingA microbiological theory of aging– Cells can divide a maximum number of Cells can divide a maximum number of

timestimes– Dividing ability decreases with ageDividing ability decreases with age– Upper limit?Upper limit?– New research since Hayflick’s theoryNew research since Hayflick’s theory

Tips of the chromosomes - telomeres Tips of the chromosomes - telomeres TelomeraseTelomerase

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Free Radical TheoryFree Radical Theory

Also a microbiological theory of agingAlso a microbiological theory of aging Cells metabolize energy.Cells metabolize energy. Cells generate waste that includes Cells generate waste that includes

unstable oxygen molecules = free unstable oxygen molecules = free radicals.radicals.

Free radicals = damage within the Free radicals = damage within the cell structure.cell structure.

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Mitochondrial TheoryMitochondrial Theory

Mitochondria = tiny cellular bodies Mitochondria = tiny cellular bodies that supply energy for functioning, that supply energy for functioning, growth, and repair.growth, and repair.

Why does mitochondria decay?Why does mitochondria decay?– Oxidative damageOxidative damage– Loss of micronutrients supplied by the Loss of micronutrients supplied by the

cellcell– Free radicalsFree radicals– Evidence for this theory?Evidence for this theory?

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Hormonal Stress TheoryHormonal Stress Theory

Aging at the hormonal level = lower Aging at the hormonal level = lower resistance & increased diseaseresistance & increased disease

Evidence: HPA or hypothalamic-Evidence: HPA or hypothalamic-pituitary – adrenal axis plays a role in pituitary – adrenal axis plays a role in aging.aging.

What happens to the HPA as we age?What happens to the HPA as we age?

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Which one is correct?Which one is correct?

We really don’t know.We really don’t know. Maybe all of them are involved.Maybe all of them are involved.