Theories of aging s14

1. Early Theories of AgingEarly Theories of Aging
Thanatophobia
Extend maximum life span
Hippocrates – gradual loss of body heat
Erasmus Darwin – reduced responses to stimuli, loss of
excitability
Others – metabolic rate, irradiation, genetics
“geriatrics” coined in 1914
First geriatric medical journal published in 1945
ACSM founded in 1954
NIA created in 1974

2. Theories of AgingTheories of Aging
Psychological
◦Maslow’s Hierarchy of Needs (1943)
◦Erikson’s Psychological Stages (1956)
◦Selective Optimization with Compensation (SOC, 1980)
Sociological
◦Activity
◦Continuity
Biological
◦Damage
◦Genetic
◦Gradual Imbalance

3. Theories of AgingTheories of Aging
Psychological
◦Primarily related to success
◦Personal development
Sociological
◦Engagement
◦Experience & environment

4. Maslow’s Hierarchy of Needs:
Theory of Successful Aging

5. Theories of AgingTheories of Aging
Erikson’s Psychosocial Stages
◦Development through late adulthood
◦Positive/Negative Outcomes
Late Adulthood
◦Pride & satisfaction vs. lack of
accomplishment
◦Dignity & acceptance vs. frustration
Keys: close relationships; productivity
with family and/or work; evaluation of the
rear view

6. Theories of AgingTheories of Aging
Selective Optimization with
Compensation (Baltes & Baltes, 1990)
◦Select priorities/likes/most important
◦Optimize skills and talents
◦Compensate for decrements in ability
Examples
◦Playing music
◦Lifting weights
◦Running

7. Theories of AgingTheories of Aging
SOC
◦Functional competence is key
Related concepts
◦Self-efficacy (Bandura, 1977)
◦Self-esteem
◦Control
◦Cognitive capacity

8. Theories of Aging: SociologicalTheories of Aging: Sociological
Activity Theory (Havighurst, 1961)
◦Engaged in mental and physical activities
◦Community/family/profession
Continuity (Atchley, 1971)
◦Carry forward positive habits, relationships,
regardless of advancing age
Can social beings successfully age without
solid social connections?
Cognitive function?

9. Theories of AgingTheories of Aging

10. Theories of AgingTheories of Aging
Damage from wear and tear
◦Chemical reactions that occur naturally in the
body begin to produce a # of irreversible
defects in molecules.
◦What is the source of “microinsults”?
Physical
Chemical
Infectious
Mechanical
Injury
Loss of function &
System failure
Repair

11. Theories of AgingTheories of Aging

12. Theories of AgingTheories of Aging
Free-radical theory (damage)
◦Chemical compounds that contain an
unpaired electron in an outer orbital
◦Able to link to tissue and cause damage

13. Theories of AgingTheories of Aging
Mitochondrial respiration–
“leaking intermediates”
Superoxide dismutase

14. Theories of AgingTheories of Aging
Free radical targets
◦Cell membranes
◦DNA & RNA
◦Enzymes
Damage to tissues, ultimately systems

15. Theories of AgingTheories of Aging
Accumulation of defects in metabolic
pathways
Does aging originate in the mitochondria?
Oxidation of mitochondrial DNA
Widespread impact

16. Theories of AgingTheories of Aging
Strategy for reducing free radicals:
◦Consumption of Vitamins E and C
“anti-oxidants”
◦Mechanism?
◦Use of supplements?

17. Theories of AgingTheories of Aging
Cross-linkage (damage)
◦Corrupted DNA not repaired
◦Cross-linking occurs in protein-based collagen
fibers
◦Over time, results in
Stiffening of tissue
Rigidity of blood vessels
Tight ligaments & tendons
Cataracts
Atherosclerosis

18. Theories of AgingTheories of Aging
Genetic theories
◦Genes related to
pathologies
◦Could dictate cellular aging
◦DNA mutations of
mitochondria build during
lifetime

19. Theories of AgingTheories of Aging
Hayflick Limit
Cells will divide & reproduce only a limited
number of times “Cell Clock”
Number is genetically programmed
Limitations

20. Theories of AgingTheories of Aging
Telomere Hypothesis
◦Shortens with each replication
of the chromosome
◦Replication at a fixed rate may
indicate that the telomere is
the “clock” that determines the
lifespan of any given cell
◦Dolly’s fate

21. Theories of AgingTheories of Aging
Gradual Imbalance Theory
◦Nervous system
◦Endocrine system
◦Impaired relationship btwn the two
Hormones impacted
Adaptation impaired
Is aging the result of decreased ability to
survive stress??

22. Theories of AgingTheories of Aging
There is no overwhelming support for
just one biological theory of aging.
Likely theories overlap and each explain
some aspect(s) of aging

23. Slowing the Aging ProcessSlowing the Aging Process
Improve nutrition
¯ total food consumed
Maintain general activity levels
Have social/community
involvement
Perform moderate amounts of
physical exercise

24. Slowing the Aging ProcessSlowing the Aging Process
Caloric restriction
◦Total amt of food is reduced
How much?
◦Major nutrients, minerals, & vitamins
necessary for health are maintained

25. Slowing the Aging ProcessSlowing the Aging Process
Biosphere 2 experiments
N = 8; ~2 years
Lower
◦Metabolic rate
◦Body temperature
◦SBP & DBP
◦Blood glucose
◦Insulin
◦Thyroid hormones
Okinawan population
Experimental data in humans?

26. Slowing the Aging ProcessSlowing the Aging Process
General activity level
◦Active in life
◦Social contacts
◦Taking care of self
◦Living the “good life”

27. Role of PA/Exercise/Sport?Role of PA/Exercise/Sport?
Compression of morbidity?
Decrease premature mortality?
SOC?
Social opportunities?

28. Quality of LifeQuality of Life
The difference between active living
& just being alive.
Active life expectancy

29. Quality of Life (more to come)Quality of Life (more to come)
Activities of Daily
Living (ADLs)
◦Walking
◦Dressing
◦Bathing/toileting
◦Eating
◦Getting up from a
bed or chair
Instrumental Activities
of Daily Living (IADLs)
◦Managing finances
◦Using the telephone
◦Light housework
◦Heavy housework
◦Meal preparation
◦Shopping
Spiritual health: Relationships,
values, purpose

30. SummarySummary
Factors that optimize
successful aging:
◦Avoiding disease
◦Engaging in life activities
◦Maintaining high cognitive and
physical function