Theories of Aging PDF

**Theories of Aging** Mrs. Regis, 27/01/2025 **Aging** - From a biologic view, aging is defined as the progressive loss of function. - The exact cause of biologic aging is unknown. - Biologic aging is a multifactorial process involving genetics, diet, and environment **Theories o...

**Theories of Aging** Mrs. Regis, 27/01/2025 **Aging** - From a biologic view, aging is defined as the progressive loss of function. - The exact cause of biologic aging is unknown. - Biologic aging is a multifactorial process involving genetics, diet, and environment **Theories of Aging** 1. **Biological Aging Theories** a. Concerned with answering basic questions regarding physiologic processes that occur in all living organisms over time (Hayflick, 1996). 2. **Psychological Aging theories** b. Influenced by both biology and sociology; addresses how a person responds to the tasks of his or her age. 3. **Social Aging Theory** c. Focused on the roles and relationships within which individuals engage in later life (Hogstel, 1995). 4. **Functional Consequences Theory** - encourages nurses to consider the effects of normal age-related changes as well as the damage incurred through disease or environmental and behavioral risk factors when planning care **Biological Aging Theories** \"All organs in any organism do not age at the same rate, and any single organ does not necessarily age at the same rate in different individuals at the same species.\" (Warner, 2004) \"The decreasing function of an organism may lead to a complete failure of either an organ or an entire system\" (Hayflick, 1996) **1.Free Radical Theory** - proposed by **Denham Farman** in 1956. - Free radicals are byproducts of fundamental metabolic activities within the body. - Free radical production may increase because of environmental pollutants such as ozone, pesticides, and radiation. - Normally, they are neutralized by enzymatic activity or natural antioxidants. However, if they are not neutralized, they may attach themselves to other molecules. - Proposes that unstable free radicals result from - oxidation of organic materials such as carbohydrates and proteins. These radicals cause biochemical changes in the cells, and the cells cannot regenerate themselves **What are free radicals?** - Free radicals are atoms that are very unstable and react quickly with other compounds in order to capture the needed electron to gain stability. - Generally, it attaches to the nearest stable molecule \"stealing its electron. When the attached molecule loses its electron, it becomes a free radical itself, beginning a chain reaction. free radical production becomes excessive, damage can occur. A screen with a diagram on it Description automatically generated - In nervous and muscle tissue, to which free radicals have a high affinity, a substance called lipofuscin has been found and is thought to be indicative of chronologic age. - Lipofuscin, a lipid- and protein-enriched pigmented material, has been found t accumulate in older adults\' tissues and is commonly referred to as \"age spots.\" As the lipofuscin\'s presence increases, healthy tissue is slowly deprived of oxygen and its nutrient supply. - Further degeneration of surrounding tissue eventually leads to actual death of the tissue. - The body does have naturally occurring antioxidants, or protective mechanisms. - Vitamins C and E are two of these substances that can inhibit the functioning of the free radicals or possibly decrease their production in the body. **Various studies and theories have connected oxidative stress due to free radicals to:** - Central nervous system diseases, such as Alzheimer\'s and other dementias - Cardiovascular disease due to clogged arteries - Autoimmune and inflammatory disorders, such as rheumatoid arthritis and
cancer - Cataracts and age-related vision decline - Age-related changes in appearance, such as loss of skin elasticity, wrinkles, graying hair, hair loss, and changes in hair texture - Diabetes - Genetic degenerative diseases, such as Huntington\'s disease or Parkinson\'s  - Vitamin C and E are 2 substances that inhibit the functioning of the free radicals or possibly decrease their production in the body. - Harman (1956) was the first to suggest that the administration of chemicals terminating the propagation of free radicals would extend the lifespan or delay the aging process. - antioxidants postpone the appearance of diseases such as cardiovascular disease and cancer **2.Cross linkage theory** - Proposes that the irreversible aging of proteins such as collagen is responsible for the ultimate failure of tissues and organs. - Proposes that as cells age, chemical reactions create strong bonds, or cross-linkages, between proteins. - These bonds cause loss of elasticity, stiffness, and eventual loss of function. - involves collagen produced by fibroblasts. - As new fibers are created, they enmeshed with old fibers and form an actual chemical crosslink. The result of this cross-linkage process is an increase in the density of the collagen molecule but a decrease in the capacity to both transport nutrients to the cells and remove waste products from the cell. This results in a decrease structures function. - referred as GLYCATION HYPOTHESIS OF AGING proposed by Johan Bjorksten in 1942. - According to this theory, an accumulation of cross-linked proteins damages cells and tissues, slowing down bodily processes resulting in aging. - In this theory it is the binding of glucose (simple sugars) to protein, (a process that occurs under the presence of oxygen) that causes various problems. - Once this binding has occurred the protein becomes impaired and is unable to perform as efficiently. **Cross-linking are associated with:** - the loss of elasticity in skin and muscle tissue hardening of blood vessel walls changes in the lens of the eye delayed wound healing - reduced joint mobility in aging individuals. A group of people looking at a screen Description automatically generated  **3.Hayflick Limit Theory** - **Dr. Leonard Hayflick** developed a theory - Called \"Hayflick Limit\" in 1965. - The concept states that a normal human - cell can only replicate and divide forty to sixty times before it cannot divide anymore and will break down by programmed cell death or apoptosis. - Developed the concept while at the Wistar Institute in Philadelphia, Pennsylvania, in 1965. **Basic Principle of Hayflick Limit Theory** - The Hayflick Limit Theory states that a healthy, normal human cell population (from fetal tissue) could only go through mitosis, or cellular duplication and division, forty (40) to sixty (60) times until it can no longer divide and lead to apoptosis (programmed cell death). The cell\'s limited replicative capability was linked to cell aging and, as a result, human aging. - Life expectancy was generally seen as preprogrammed within a species-specific range; this biologic clock for humans was estimated at 110 to 120 years (Gerhard & Cristofalo, 1992; Hayflick, 1996). - Based on the conclusions of this experiment, the Hayflick Limit Theory is sometimes called the \"Biologic Clock Theory,\" \"Cellular Aging Theory,\" or \"Genetic Theory.\" **What\'s the Hayfick limit got to do with aging?** - In normal, replicating cells, all the important genetic code in a cel\'s nucleus is protected by telomeres - sections of non-coding DNA on the ends of chromosomes. (Elizabeth Blackburn, who won a Nobel for her work on telomeres, compares them to the caps on the end of shoelaces that keep them from fraying.) Every time cells divide, telomeres shorten ever so slightly; the white blood cells in newborn humans have telomeres that consist of about 8.000 base pairs, which falls to around 1,500 in the elderly. **Senescent cells** are a culprit in aging, but they also have benefits. They give off proteins that can recruit immune cells, which can promote wound healing, and they\'re one of our body\'s defenses against cancer. One of the reasons cancers occurs is when cells switch on a gene that allows them to rebuild their telomeres-kind of like speeding through a stop sign. That\'s why the only immortal human cells are cancer cells. **As a result of this information, two areas of specialized research have emerged:** - **Telomere Lengthening for Human Cells**: Telomere restoration is prevented by the presence of telomerase inhibitors, allowing cancer cells to die like other body cells, which has been used as a cancer treatment. - **Telomere Shortening for Cancer Cells:** The use of telomerase inhibitors is one proposed therapy approach for stopping cancer cell proliferation. By reducing the enzyme\'s impact, their telomeres shorten and die like other cells in the body, allowing doctors to remove them. **4.Immunologic Theory** - **Roy Walford** who first coined the commonly used term \"immunosenescence\". - In 1969, Roy Walford published his landmark book, \"The Immunologic Theory of Aging\", which has now become a classic. **Immunosenescence** - Proposes that the immune system becomes less effective with age, resulting in reduced resistance to infectious disease and viruses. - Proposes that a decrease in immune function may result in an increase in autoimmune responses, causing the body to produce antibodies that attack itself. **5.Endocrine Theory** - Proposes that events occurring in the hypothalamus and pituitary are responsible for changes in hormone production and response that result in the organism\'s decline. Levels of most hormones decrease with aging, but some hormones remain at levels typical of those in younger adults, and some even increase. Even when hormone levels do not decline, endocrine function generally declines with age because hormone receptors become less sensitive. - Some hormones that decrease include - Estrogen (in women) - Testosterone (in men) - Growth hormone - Melatonin **Low Estrogen** - absent or irregular periods bone fractures due to osteoporosis infertility in males or females decreased libido in males or female's erectile dysfunction in males high cholesterol or high triglycerides coronary heart disease - Pain during intercourse - Urinary tract infections (UTIs) **Low testosterone** - is common in males as they get older. - Low sex drive - Difficulty achieving and maintaining an erection - Hot flashes - Hair loss - Fatigue - Decreased muscle mass - Increased body fat - Decreased bone mass - Mood changes - Affected memory - Smaller testicle and penis size - Low blood counts **Melatonin** - We begin to produce less melatonin. - With age, the pineal gland simply does not store and release melatonin as effectively due to calcification. - Changes in vision may also contribute to this decline in melatonin. - Although melatonin is 8-10 times as high at night compared to during the day in a healthy young adult, the elderly have night levels that are just twice that of their daytime levels. **6. Wear and Tear Theory** - An idea proposed by German biologist, **Dr. August Wiesmann**, in 1882. - It asserts that the effects of aging are caused by progressive damage to cells and body systems over time. Essentially, our bodies \"wear out\" as a result of use. They can no longer function properly once they have worn out. - Proposes that humans, like automobiles, have vital parts that run down with time, leading to aging and death. - Proposes that the faster an organism lives, the quicker it dies. - Proposes that cells wear out through exposure to internal and external stressors, including trauma, chemicals, and buildup of natural wastes. **Implications for Nursing** **Gerontologic nurses can promote the health of older adult patients in many ways.** 1. **Helping with smoking cessation would be one example of health promotion.** - Cigarette smoking causes increased cell turnover in the oral cavity, bronchial tree, and alveoli. - Smoking also introduces carcinogens into the body, which may result in an increased rate of cell damage that can lead to cancer ST. 2. **Nurses can develop a health promotional activity for education regarding sun exposure.** - Excessive exposure to ultraviolet light is another example of a substance causing rapid turnover of cells, which may lead to mutations and ultimately malignancies. 3. **To reduce free radical damage, nurses can also advise patients to ingest a varied, nutritious diet using the food pyramid as a guide and suggest supplementation with antioxidants such as vitamins C and E** 4. **Physical activity continues to play an important role in the lives of older adults.** - Daily routines need to incorporate opportunities that capitalize on existing abilities, strengthen muscles, and prevent further atrophy of muscles from disuse. - Encouraging older adults to participate in activities may prove a challenge to nurses interacting with these patients - Performing activities of daily living (ADLs) requires the functional use of extremities. - Daily exercises that enhance upper arm strength and hand dexterity contribute to older adults\' ability to successfully perform dressing and grooming activities. - Even chair-based activities such as deep breathing increase the oxygen flow to the brain, thereby promoting clear mental cognition, minimizing dizziness, and increasing stamina with activity. **Sociological Aging Theories** Sociologic theories on ageing explain how changing roles, relationships, and status within a culture or society impact an older adult\'s ability to adapt and how these individuals perceive their roles within a community. **1.Activity Theory** - Individuals need to remain active to age successfully. Activity is necessary to maintain life satisfaction and a positive selfconcept (Havighurst, Neugarten, & Tobin, 1963). - proposed that older adults should stay active and engaged if they are to age successfully - Happiness and satisfaction with life are assumed to result from higher level of involvement with the world and continued social involvement. - Havighurst first wrote the importance of remaining socially active as a means to healthy environment to old age in 1952. A screen with blue text Description automatically generated **2.Continuity Theory** - Individuals will respond to aging in the same way they have responded to previous life events. The same habits, commitments, preferences, and other personality characteristics developed during adulthood are maintained in older adulthood (Havighurst, Neugarten, & Tobin, 1963). - this theory claims that people need to maintain their desired level of activity and involvement in society to maximize well being. - this theory advances that successful aging involves maintaining or continuing previous values, habits, preferences, family ties and all other linkages that have formed the basic underlying structure of adult life. **NURSING IMPLICATIONS** - Client\'s activities/lifestyle must be maintained if possible and in a less strenuous manner, as long as there are no contraindications - Nurses must include in the care to let the client stay in contact with family and friends even those during his university years. - Nurses must respect the client\'s decisions and choices for this were based on the client\'s tactics from his prior experiences **3.Age Stratification Theory** Society consists of groups of cohorts that age collectively. The people and roles in these cohorts change and influence each other, as does society at large. Therefore, a high degree of interdependence exists between older adults and society (Riley, 1985). - The theory attempts to explain the interdependence between older adults and society, and how they constantly influence each other in a variety of ways. **4.Person-Environment Fit Theory** - Everyone has personal competencies that assist the person in dealing with the environment. These competencies may change with aging, thus affecting the older person\'s ability to interrelate with the environment (Lawton, 1982). - The theory further proposes that, as a person ages, the environment becomes more threatening, and he or she may feel incompetent dealing with it. **Implications for Nursing** - all older adults cannot be grouped collectively as just one segment of the population. Many differences exist within the aged population. - The young-old (ages 65 to 74), the middle-old (ages 75 to 84), the old-old (more than 85), - the elite-old (more than 100 years old) are four distinct cohort groups, and the individuals within each of these cohort groups have their own history - Using assessment skills and specific tools, nurses can further investigate and plan appropriate interventions to help resolve a potentially adverse situation. - Older adults may refuse to engage in an activity because of fear of failure or frustration at not being able to perform the activity. Planning realistic activities for particular patient groups is crucial to successful group interaction. - Another application of the sociologic theories relates to helping individuals adapt to various limitations and securing appropriate living arrangements. Most buildings are now easily accessible to those with special needs. These special needs may include doorways wide enough for wheelchairs, ramps in addition to stairs, handrails in hallways, and working elevators.