Early Theories of AgingEarly Theories of Aging

Thanatophobia

Extend maximum life spanHippocrates – gradual loss of body heatErasmus Darwin – reduced responses to stimuli,

loss of excitabilityOthers – metabolic rate, irradiation, genetics“geriatrics” coined in 1914First geriatric medical journal published in 1945ACSM founded in 1954NIA created in 1974

Theories of AgingTheories of AgingPsychological

◦ 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

Theories of AgingTheories of AgingPsychological

◦Primarily related to success◦Personal development

Sociological◦Engagement◦Experience & environment

Maslow’s Hierarchy of Needs: Theory of Successful Aging

Theories of AgingTheories of AgingErikson’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

Theories of AgingTheories of AgingSelective 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

Theories of AgingTheories of AgingSOC

◦ Functional competence is keyRelated concepts

◦ Self-efficacy (Bandura, 1977)◦ Self-esteem◦ Control ◦ Cognitive capacity

Theories of Aging: Theories of Aging: SociologicalSociologicalActivity Theory (Havighurst, 1961)

◦Engaged in mental and physical activities

◦Community/family/professionContinuity (Atchley, 1971)

◦Carry forward positive habits, relationships, regardless of advancing age

Can social beings successfully age without solid social connections?

Cognitive function?

Theories of AgingTheories of Aging

Theories of AgingTheories of AgingDamage 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

Theories of AgingTheories of Aging

Theories of AgingTheories of AgingFree-radical theory (damage)

◦Chemical compounds that contain an unpaired electron in an outer orbital

◦Able to link to tissue and cause damage

Theories of AgingTheories of Aging

Mitochondrial respiration– “leaking intermediates”

Superoxide dismutase

Theories of AgingTheories of AgingFree radical targets

◦Cell membranes◦DNA & RNA◦Enzymes

Damage to tissues, ultimately systems

Theories of AgingTheories of AgingAccumulation of defects in

metabolic pathwaysDoes aging originate in the

mitochondria?Oxidation of mitochondrial DNAWidespread impact

Theories of AgingTheories of AgingStrategy for reducing free

radicals:◦Consumption of Vitamins E and C

“anti-oxidants”

◦Mechanism?◦Use of supplements?

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

Theories of AgingTheories of Aging

Genetic theories◦Genes related to

pathologies ◦Could dictate cellular

aging◦DNA mutations of

mitochondria build during lifetime

Theories of AgingTheories of Aging

Hayflick Limit Cells will divide & reproduce only a limited

number of times “Cell Clock” Number is genetically programmed

Limitations

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

Theories of AgingTheories of AgingGradual Imbalance Theory

◦Nervous system◦Endocrine system◦Impaired relationship btwn the two

Hormones impactedAdaptation impairedIs aging the result of decreased

ability to survive stress??

Theories of AgingTheories of AgingThere is no overwhelming support for just one biological theory of aging.

Likely theories overlap and each explain some aspect(s) of aging

Slowing the Aging ProcessSlowing the Aging Process

Improve nutrition total food consumedMaintain general activity levels

Have social/community involvement

Perform moderate amounts of physical exercise

Slowing the Aging ProcessSlowing the Aging ProcessCaloric restriction

◦Total amt of food is reduced How much?

◦Major nutrients, minerals, & vitamins necessary for health are maintained

Slowing the Aging ProcessSlowing the Aging ProcessBiosphere 2 experimentsN = 8; ~2 yearsLower

◦ Metabolic rate◦ Body temperature◦ SBP & DBP◦ Blood glucose◦ Insulin◦ Thyroid hormones

Okinawan populationExperimental data in

humans?

Slowing the Aging ProcessSlowing the Aging ProcessGeneral activity level

◦Active in life◦Social contacts◦Taking care of self◦Living the “good life”

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

Quality of LifeQuality of Life

The difference between active living & just being alive.

Active life expectancy

Quality of Life (more to Quality of Life (more to come)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

SummarySummaryFactors that optimize

successful aging:◦Avoiding disease◦Engaging in life activities◦Maintaining high cognitive

and physical function