Theories of Aging PDF
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This presentation discusses various theories of aging, categorizing them as biological, sociological, and psychological. It examines stochastic theories like free radical and cross-linkage, and non-stochastic theories such as programmed theories. The presentation also explores emerging areas of research in aging, including neuroendocrine control and DNA-related research.
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THEORIES OF AGING ¬Theories of Aging: ¬attempt to explain the phenomenon of aging as it occurs over the lifespan – aging is viewed as a total process that begins at conception – senescence: a change in the behavior of an organism with age leading to a decreased power of survival an...
THEORIES OF AGING ¬Theories of Aging: ¬attempt to explain the phenomenon of aging as it occurs over the lifespan – aging is viewed as a total process that begins at conception – senescence: a change in the behavior of an organism with age leading to a decreased power of survival and adjustment Theories of Aging: Types ¬Biologic: ¬ Stochastic ¬ Non Stochastic ¬Sociologic ¬Psychologic ¬Moral/Spiritual Biologic Theories: ¬Concerned regarding the physiological processes that occur in all living organisms as they chronologically age. Foci of Biologic Theories ¬Explanations of: – 1) deleterious effects leading to decreasing function of the organism – 2) gradually occurring age-related changes that are progressive over time – 3) intrinsic changes that can affect all member of a species because of chronologic age ¬ALSO: – all organs in any one organism do not age at the same rate – any single organ does not necessarily age at the same rate in difference individuals of the same species Biologic Theories: Divisions ¬Stochastic: Explain aging as events that occur randomly and accumulate over time. ¬Nonstochastic: View aging as certain predetermined, timed phenomena ¬Stochastic Theories ¬Error Theory Free Radical Theory ¬Cross-Linkage Theory ¬Wear & Tear Theory Error Theory ¬Basis: 1) Errors can occur in the transcription in any step of the protein synthesis of DNA Ex. DNA Mutations – exposure to environmental factors: radiation or chemicals Error Theory ¬Basis: 2) Error causes the reproduction of an enzyme or protein that is not an exact copy. Ex. Protein Misfolding – form clumps or aggregates that can interfere with cellular process. = Alzheimer’s disease & Parkinson Error Theory ¬Basis: - 3) As transcription errors to occur, the end product would not even resemble the original cell, thereby compromising its functional ability. Ex. Telomere Shortening – cannot divide properly and may enter to a state of senescence and die. = tissue aging and age – related disease. Free Radical Theory Free radicals are byproducts of metabolism--can increase as a result of environmental pollutants. When they accumulate, they damage cell membrane, decreasing its efficiency. The body produces antioxidants that neutralize the free radicals. Free Rads, cont’d ¬ importance of antioxidants in the diet, which can help neutralize free radicals and potentially slow down the aging process. – Vit. C, Vit. E, Beta-Carotene, Lycopene, Flavonoids. ¬ Free radicals are also implicated in the development of plaques associated with Alzheimer’s Cross-Linkage Theory ¬Some proteins in the body become cross- linked, thereby not allowing for normal metabolic activities ¬Waste products accumulate ¬Result: tissues do not function at optimal efficiency Cross-Linkage Theory C-L Theory, cont’d ¬Some research supports a combination of exercise and dietary restrictions in helping to inhibit the cross-linkage process Wear & Tear Theory ¬Cells simply wear out over time because of continued us-rather like a machine. ¬Nonstochastic Theories: ¬Programmed Theory ¬Immunity Theory Programmed (Hayflick Limit) Theory ¬Cells can only reproduce themselves a limited number of times. The Hayflick phenomenon, or human fibroblast replicative senescence model suggests that cells replicate until they can no longer divide. ¬Life expectancies are seen as preprogrammed within a species-specific range Immunity Theory ¬Immunosenescence: Age-related functional diminution of the immune system ¬Lower rate of T-lymphocyte (“killer cells”) proliferation in response to a stimulus ¬& therefore a decrease in the body’s defense against foreign pathogens. Immunity, cont’d ¬Change include a decrease in humoral immune response, often predisposing older adults to: – 1)decreased resistance to a tumor cell challenge and the development of cancer – 2) decreased ability to initiate the immune process and mobilize defenses in aggressively attaching pathogens – 3) increased susceptibility to auto-immune diseases EMERGING THEORIES OF AGING ¬Neuroendocrine Control (Pacemaker) Theory ¬Metabolic Theory/Caloric Restriction ¬DNA-Related Research Neuroendocrine Control ¬“…examines the interrelated role of the neurologic and endocrine systems over the life-span of an individual”. ¬there is a decline, or even cessation, in many of the components of the neuroendocrine system over the lifespan Neuro, cont’d ¬Research has shown – 1) the female reproductive system is controlled by the hypothalamus. What are the mechanisms that trigger changes? – 2) adrenal glands’ DHEA hormone – 3) melatonin (from pineal gland)--a regulator of biologic rhythms and a powerful antioxidant. Declines sharply from just after puberty Metobolic Theory of Aging (Caloric Restriction) ¬“…proposes that all organisms have a infinite amount of metabolic lifetime and that organisms with a higher metabolic rate have a shorter lifespan”. DNA-Related Research ¬Major Developments: – Mapping the human genome (“…there may be as many as 200 genes responsible for contolling aging in humans”) – Discovery of telomeres Every time a cell divides, its telomeres become slightly shorter. This shortening process is a normal part of aging. However, as telomeres become progressively shorter with each cell division, they eventually reach a critical length. When this happens, cells can no longer divide, and they become senescent or die. SOCIOLOGIC THEORIES OF AGING ¬Disengagement Theory ¬Activity/Developmental Task Theory ¬Continuity Theory ¬Age Stratification Theory ¬Person-Environment Fit Theory ¬Changing FOCUS of Sociological considerations of aging: – 60’s focus on losses and adaptation to them – 70’s broader global, societal, and structural factors influencing lives of OA’s – 80’s-90’s exploration of interrelationships between OA’s and their physical, political, environmental & socioeconomic mileau Disengagement Theory ¬Cumming & Henry-- 1961 ¬ is a straightforward idea about how people and society change as they get older. It suggests that as people age, they tend to withdraw or disengage from many of their previous roles and activities. Disengagement Theory ¬Withdrawal from Society: As people get older, they might start to step back from their active involvement in work, social activities, or community roles. Disengagement Theory Reduced Responsibilities: They might give up certain responsibilities or roles they had when they were younger, like leadership positions or demanding jobs. More Personal Time: Instead, they may prefer to spend more time focusing on themselves, their families, or their close friends. Disengagement Theory ¬Acceptance of Change: This theory suggests that this disengagement is a natural and healthy part of aging, allowing older individuals to adjust to changes in their abilities and priorities. Activity Theory (Developmental Task Theory) ¬Havighurst, Neugarten, Tobin ~1963 ¬“ This theory suggests that older adults remain happier and more satisfied with their lives if they stay active and engaged in activities. ¬This theory proposes that maintaining a high level of activity and involvement in various aspects of life is crucial for successful aging. Activity, cont’d ¬Theory based on assumptions: – 1) it’s better to be active than inactive Continued Engagement – 2) it is better to be happy than unhappy Benefits of Activity – 3) an older individual is the best judge of his or her own success in achieving the first two assumptions. Positive Aging Continuity Theory ¬How a person has been throughout life is how that person will continue through the remainder of life ¬Old age is not a separate phase of life, but rather a continuation and thus an integral component Continuity Theory ¬ASSUMPTIONS: ¬Consistency and Stability: According to the Continuity Theory, people prefer to maintain a sense of continuity in their lives as they age. They strive to preserve their familiar patterns of behavior, interests, and relationships. Continuity Theory ¬ASSUMPTIONS: Adaptation within Continuity: While individuals may face changes due to aging, such as retirement or health issues, they seek to adapt within the framework of their established identities and routines. They may adjust their activities or roles to accommodate these changes while still preserving a sense of continuity. Continuity Theory ¬ASSUMPTIONS: ¬ Importance of Past Experiences: Past experiences, values, and beliefs continue to shape individuals' lives as they age. They draw on their accumulated knowledge and skills to navigate new challenges and maintain a sense of identity and purpose. Continuity Theory ¬ASSUMPTIONS: ¬Social Connections: Relationships with family, friends, and community play a crucial role in maintaining continuity. Older adults often prioritize maintaining these social connections, which provide a sense of belonging and support. Age Stratification Theory ¬Riley--1985 ¬Society consists of groups of cohorts that age collectively. – Age groups: children, young adults, middle- aged adults, and older adults. Age Stratification Theory ¬The people & roles in these cohorts change & influence each other, as does society at large. – Differential treatment: Example: older adults may face age-related discrimination in employment or healthcare Age Stratification Theory ¬In many societies, retirement age is often set at a specific chronological age, such as 65 years old. Person-Environment Fit Theory ¬Lawton, 1982 ¬Individuals have personal competencies that assist in dealing with the environment: – ego strength – level of motor skills – individual biologic health – cognitive & sensory-perceptual capacities P-E Fit, cont’d ¬As a person ages, there may be changes in competencies & these changes alter the ability to interrelate with the environment ¬Significant implications in a society that is characterized by constantly changing technology PSYCHOLOGIC THEORIES OF AGING ¬Maslow’s Hierarchy of Human Needs ¬Jung’s Theory of Individualism ¬Erikson’s Eight Stages of Life ¬Peck’s Expansion of Erikson’s Theory ¬Selective Optimization with Compensation Maslow’s Hierarchy of Human Needs ¬Maslow--1954 ¬“…each individual has an innate internal hierarchy of needs that motivates all human behaviors”. ¬depicted as a pyramid; the ideal is to achieve self-actualization, having met all the “lower” level needs successful ¬“Maslow’s fully developed, self-actualized person displays high levels of all of the following characteristics: perception of reality; acceptance of self, others, and nature; spontaneity; problem-solving ability; self-direction; detachment and the desire for primacy; freshness of peak experiences; identification with other human beings;……. ¬…satisfying and changing relationships with other people; a democratic character structure; creativity; and a sense of values. ¬Only about 1% of us are truly ideal self- actualized persons Jung’s Theory of Individualism ¬Carl Jung--1960 ¬Self-realization is the goal of personality development ¬as individual ages, each is capable of transforming into a more spiritual being. Jung’s Theory of Individualism ¬ Spiritual Growth: Jung believed that aging provides an opportunity for individuals to connect with their spiritual essence and develop a deeper sense of spirituality. This may involve exploring concepts such as transcendence, interconnectedness, and the nature of existence. Jung’s Theory of Individualism ¬ Wisdom and Insight: As individuals undergo spiritual growth, they may gain wisdom and insight into the human condition, as well as empathy and compassion for others. This wisdom can enrich their lives and relationships, fostering a deeper sense of connection and belonging. Erikson’s Eight Stages of Life ¬1993 ¬Stages throughout the life course. Each represents a crisis to be resolved. ¬For OA’s: – 40 to 65 (middle adulthood): generativity versus self-absorption or stagnation – 65 to death (older adulthood): ego integrity versus despair Erikson, cont’d ¬“Self-absorbed adults will be preoccupied with their personal well-being and material gains. Preoccupation with self leads to stagnation of life” ¬“Unsuccessful resolution of the last crisis may result in a sense of despair in which individuals view life as a series of misfortunes, disappointments, and failures”. Peck’s Expansion of Erikson’s Theory ¬The final three of the developmental tasks for old age: – ego differentiation versus work role preoccupation. Ex. Work and Life balance. Peck’s Expansion of Erikson’s Theory ¬The final three of the developmental tasks for old age: – body transcendence versus body preoccupation. Peck’s Expansion of Erikson’s Theory ¬The final three of the developmental tasks for old age: – EGO TRANSCENDENCE VS. EGO PREOCCUPATION – ego transcendence strong sense of empathy, compassion, and interconnectedness with others and the world around them. – ego preoccupation. overly focused on their personal ego, desires, and concerns. People with ego preoccupation may prioritize self-interest, self-aggrandizement, or self-protection above all else. Selective Optimization with Compensation ¬Baltes--1987 ¬Individuals develop strategies to manage losses of function that occur over time Selective Optimization, cont’d ¬3 Interacting Elements: – selection: increasing restriction of one’s life to fewer domains of functioning – optimization: people engage in behaviors to enrich their lives – compensation:developing suitable, alternative adaptations THE END! ¬Thanks for hanging in there!