THEORIES OF AGING

1.INTRODUCTION

There is no single universally accepted definition of aging. Aging is series of changes that occur over time, contribute to loss of function and ultimately result in the death of a living organism.

2.BIOLOGIC THEORIES

Biologic theories of aging attempt to explain why the physical changes occur.

Researcher try to identify which biologic factors have the greatest influence or longevity.

2.1 The programmed theory à proposed that every person has a “biological clock” that starts ticking at the time of conception. In this theory each individual has a genetic program specifying an unknown but predetermined number of cells divisions.

2.2 The run – out- program theory à proposes that every person has a limited amount of genetic material that will run out over a time

2.3 The living theory à which proposes that individuals have a finite numbers of breaths or hearts beats that are used up over a time.

2. 4 The gen theory à proposes that the existence of one or more harmful genes that active over time resulting in the typical changes seen with aging and limiting the life span of the individual

2.5 The molecular theories à propose that aging is controlled by genetic materials that are encoded to predetermine growth and decline

2. 6 The error theory à propose that error in ribonucleic acid, protein synthesis cause errors to occur in cells in the body, resulting in a progressive decline in biologic function

2. 7 The Somatic mutations theory à is similar but proposes that aging results from DNA damage causes by exposure the chemical or radiation and that this damage causes chromosomal abnormalities that lead to disease or loss function later in life

2. 8 The Free Radical Theory à the free radical theory provides a one explanation for cell damage. Free radicals are unstable molecules produces by the body during the normal metabolism or following exposure to radiation and pollution. These free radicals are suspected to cause damage to the cells, DNA, and the Immune system. Excessive accumulation of free radicals are suspected to cause free damage to the cells, DNA, and the immune system.

Excessive accumulation of free radicals in the body is purported to cause or contribute to the physiologic changes of aging and a variety of diseases.

One free radical named lipofuscin has been identify to cause a build-up of fatty pigments granules that cause age spots in older adults. Individuals who support this theory propose that the number of free radicals can be reduced by the use of antioxidants such as vit A, C, E, carotenoids, zinc, selenium and phytochemicals.

2.9 The Cross Line à also called connective tissue theory. Is one variation of the free radical theory, which propose that cell molecules from DNA and connective tissue interact with free radicals to cause bonds that decrease the ability if tissue to replace itself. These results in the skin changes typically attributed to aging such as dryness, wrinkles, and loss of elasticity

2. 10 The Clinker Theory à combines somatic mutation, free radicals, and crosslink theories to suggest that chemicals produces by metabolism accumulate un normal cells and cause damage to body organs such as the muscles, heart, nerves and brain.

Presumes that the body is similar to a machine which loses function when its parts wear out. As a people age their cells tissues and organs are damaged by internal or external stressors.

2. 11 The Neuroendocrine theory à  focuses on the complicated of chemical interactions set off by the hypothalamus of the brain. Stimulation or inhibition of various endocrine glands by the hypothalamus initiates the release of the various hormones from pituitary and other gland which in turn regulated bodily functions, including growth, reproductions and metabolism. With age the hypothalamus appears to be less precise in regulating endocrine function leading to age related changes such as decreased muscle mass…

2. 12 The immunologic theory à proposes that aging is a function of changes in the immune system. According to this theory, the immune system weakens over time making an aging person more susceptible to disease. The immunologic theory also proposes that the increase in autoimmune diseases and allergies seen with aging is caused by changes in the immune system

3.PSYCHOSOCIAL THEORIES

Psychosocial theories of aging do not explain why the physical changes of aging occur; rather they attempt to explain why older adults have different response to the aging process

3.1 The disengagement theory à was developed to explain why aging persons separate from the mainstream of society. This theory propose that older people are systematically separated, excluded or disengaged from society because they are not perceived to de of benefit to the society as a whole. This theory further propose that older adult desire to withdraw from society as the age, so the disengagement is mutually beneficial, Critics if this theory believe that it attempts to justify ageism over simplifies the psychosocial adjustment to aging and fails to address the diversity and complexity of older adults.

3.2 The activity theory à proposes that activity is necessary to successful aging. Active participation in physical ad mental activities helps maintain functioning well into old age. Purposeful activities and interactions that promote self- esteem improve overall satisfactions with life, even at older age.  

3.3. Life course theories à are perhaps the theory best known to nursing. These theories trace personality and personal adjustment throughout a person’s life. Many of these theories are specific in identifying life oriented tasks for the aging person. Four of the mist common theories:

- Erikson’s: identifies 8 stages of developmental tasks that an individual must confront throughout the life span: 1. Trust versus mistrust. 2. Autonomy vs shame and doubt. 3. Initiative vs guilt. 4. Industry vs inferiority. 5. Identify vs identity confusion. 6. Intimacy vs isolation. 7. Generativity vs stagnation. 8. Integrity vs despair.

-       Havighurst’s theory: details the process of aging and defines specific tasks for late life, including:

o   Adjusting to decreased physical strength and health

o   Adjusting to retirement and decreased income

o   Adjusting to the loss of a spouse

o   Establishing relationship with one’s age group

o   Adapting to social roles in a flexible way

o   Establishing satisfactory living arrangements.

-       Jung’s theory: propose that development continues through life by a process of searching, questioning and setting goals that are consistent whit the individual’s personality.

As individual age, they go thought a re- evaluation stage at…

As aging continues, Jung propose that the individuals is likely to ship from an outward focus to more inward focus. Successful aging according to Jung includes acceptance and valuing of the self without to the view of others.  

  

IMPLICATIONS FOR NURSING

Nursing can helps individuals achieve the longest healthiest live possible, promoting good health, maintenance practice and a healthy environment. Psychosocial theories help explain the variety of behaviours seen in the aging populations. Understanding all of these theories can help nurses recognize problems and provide nursing interventions.

From my point of view as student, nurses and nurse researchers are in key positions to educate, detect and refer, intervene, and create new strategies for those at risk of developing cognitive impairment. As health educators, nurses can talk to patients, family members, and communities about ways to promote successful cognitive aging. Preventive health strategies to recommend include avoiding substance use, exercising, and eating well, as well as staying cognitively viable through educational pursuits, mentally stimulating activities, and cognitive remediation therapy.

A point to stress regarding mental stimulation is that such activities must be novel and challenging. Novelty encourages neural plasticity, which results in maintaining or improving cognitive reserve. The mental stimulation must make participants' "brains sweat"—a corollary to physical exercise.

Nurses should encourage older adults to use a variety of cognitive strategies; relying on the same type of stimulation, such as crossword puzzles, is not mentally stimulating if this is the only type of cognitive exercise in which one engages.

BIBLIOGRAPHY:

- Farley, A. - McLafferty, E. - Hendry, C., The Physiological effects of ageing implications for nursing practice, 2010, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995895/

-  HOFFMAN, Gloria Basic Geriatric Nursing 5th Edition. Elsevier 2012. 

- Mark Stibich, Ph.D, Programmed Theories of Aging, About.com, 2007, http://longevity.about.com/od/researchandmedicine/p/age_programmed.htm