Robert Browning’s view on aging is summed up in his immortal poem, “Rabbi Ben Ezra”
Grow old along with me, the best is yet to be.
The last of life, for which the first was made;
Our times are in His hands, who saith,
A whole I planned , Youth shows but half,
Trust God: see all, nor be afraid.
The second “half of life” can be something to anticipate and enjoy if we are free of chronic diseases and their consequences. To age successfully we need to understand how our “bodies metabolize time” and how “our beliefs become biology”. How we age is largely in our own hands.
Science tells us the maximum life span for humans is 130 years. According to the United States census in 2000, there were nearly 35 million Americans over age 65 (20.6 million women and 14.4 men). This is a 12% increase in only 10 years from the 1990 Census. The Centers for Disease Control and Prevention predicts that a 65 year-old man in the year 2000, could expect to live another 16.6 years or until about 81.6 years of age. A 65 year-old woman in the year 2000 could expect to live almost another 20 years (19.5) or until the age of 84.5. Whether or not we make it to life expectancy or to 100 plus years of age, our genes, environment, life style and our perceptions of the world in which we live will determine how old we will become.
There are several types of aging; biological, chronological, cosmetic, social, psychological, and economic and a number of theories of aging; physiological, evolutionary, programmed, network theories. This paper will focus on the biological and psychological aspects of aging due to internal and external environmental factors and our perceptions of these events. Using the Stress Theory on Aging we will discuss the how this flight or fight response affects our body’s metabolism and how our minds can change aging.
The Stress Theory of Aging or the fight or flight theory is our body’s response to stress either real or perceived. In a threatening event, be it a lion at our heels or boss at our throats, our brain triggers various hormones to be released in the body directing more blood to our brains and energy to our muscles enabling us to deal with the event. In the past, it has been this mechanism that has enabled our species to survive. However, most of us do not have to outrun a lion. Today our external stressors or more related to work, family, social situations and environment such as noise, traffic, and even the weather. Our internal stressors include illness and our perceptions of life’s events.
If a stressful event happens or you even think something stressful is about to happen, our HPA axis (hypothalamus, pituitary gland and adrenal gland) is called into action. The hypothalamus secrets and array of hormones including peptides, into the hypothalamic-pituitary circulatory system. Peptides stimulate or inhibit our pituitary gland to release various hormones.
The major hormone is called CTH (corticotrophin releasing hormone). It is synergized with a variety of minor hormones. Within seconds, CTH causes the pituitary gland to release yet another hormone, ACHT (corticotrophin). When ACTH reaches the adrenal gland via the bloodstream, glucocorticoids (cortisol) is released.
The adrenal gland also secrets adrenaline. Adrenaline acts within seconds of the event, glucocorticoids augment adrenaline over the course of minutes or hours. Cortisol, the “stress hormone” is also needed for the functioning of almost every part of the body including regulation of blood pressure, cardiovascular function, regulation of the body’s use of proteins, carbohydrates, and fats. During stress, cortisol causes the breakdown of muscle protein releasing amino acids (protein’s building blocks) into the bloodstream. The liver uses the amino acids to synthesize glucose for energy. This raises the blood sugar level so the brain will have increased energy from the glucose while other tissues of the body decrease their use of glucose. Cortisol also causes the release of fatty acids from fat cells, an energy source for muscles. This complex hormone ensures the brain has adequate resources and the individual has the energy to deal with the stress.
Stress, perceived (psychological) or real, such as illness, trauma, surgery, temperature extremes, and lions can also cause the pancreas to release a hormone called glucagon. These hormones; glucocorticoids (cortisol), glucagons, and the sympathetic nervous system raise circulating levels of the glucose (sugar) in our bodies enabling us to survive threatening situations.
Death of a family member or close a friend, illness, lose of a job, financial difficulties, marital problems, and caregiving are common stressors today resulting in high levels of cortisol remaining in the bloodstream. Chronic stress and elevated levels of the stress hormone have been associated with weight gain, persistent fatigue, diabetes, and chronic depression.
Our bodies do a poor job of distinguishing between life-threatening situations and stressful everyday events. Trouble begins when the stress response is never fully turned off. Cortisol, a steroidal hormone, can stay in our bloodstream for prolong periods of time due to chronic stressful lives. Cortisol can affect homeostasis in all our body systems leading to chronic conditions and premature aging.
Stressful events reroute the energy that normally is used for cell renewal, building new proteins and manufacturing new DNA and RNA. Normal metabolism, that builds the body, is converted catabolic metabolism which breaks down our body’s tissues.
In cases of chronic stress catabolic metabolism effects can become diseases as normal body functions are tuned off to prepare our bodies to deal with the threat. The following table is an excerpt from Dr. Chopra’s Book, “Ageless Body, Timeless Mind”
- Stress Response
- Mobilized energy
- Increased cardiovascular activity
- Suppressed digestion
- Suppressed growth
- Suppressed reproduction
- Suppression of the immune response
- Increased risk of disease
- Sharpening of thought and Perception
- Disease Result
- Fatigue, muscle destruction, diabetes
- Stress-induced hypertension
- Psychogenic dwarfism
- Neuron damage or death
- Impotence, loss of libido, interruption of Menstruation
Excess cortisol is called hypercortisolism or Cushing’s disease. Addison’s disease occurs when the adrenal glands do not produce enough cortisol. A blood test called a hydrocortisone test is used to diagnose both Cushing’s and Addison’s disease.
Other health problems exacerbated by stress or attributed to stress include; allergic skin reactions, anxiety, constipation, cough, dizziness, heartburn, infectious diseases such as colds and herpes, irritable bowel syndrome, morning sickness, hot flashes, nervousness, headaches, muscle pain, slow wound healing, trouble sleeping, cancer and depression.
Depression and stress seem to go hand in hand. According to the findings from the Swedish Adoption/Twin Study of Aging, previous negative life events predict depressive symptoms and depressive symptoms also predict future negative life events.
Major depression is far more than simple sadness. It is a total loss of pleasure in the things that you once enjoyed. Depression can cause sleep and eating problems even a sense of worthlessness. You may feel apathetic or even suicidal. The DSM IV (Diagnostic and Statistical Manual of Mental Disorders, 4th edition) states, a typical major depressive episode lasts at least two weeks and can affect more than your emotions, appetite, and sleep. Depression can alter your ability to deal with anger, your outlook, libido, self-esteem, concentration, increase anxiety, cause restlessness and a muted affect slowing your movements and even your speech.
Cortisol levels, the stress hormone, are typically abnormal in people who have been diagnosed with clinical depression. It appears the excessive secretion of this hormone is due to feedback resistance i.e. the brain is not effective in shutting down cortisol secretion. Cortisol can alter the neurotransmitters system, serotonin norepinephrine and dopamine in depressed individuals as well as persons under chronic stress.
Depression is the single greatest cause of problem disability across the world, especially for older adults. Decrements include declines in emotional, cognitive and physical functioning (IADL/ADL). A major depression may even produce a dementia syndrome referred to as pseudodementia. As the degree of disability increases with the depression the likelihood of recovery decreases with each additional symptom. To improve the quality of life for all who suffer from depression, especially older adults, the diagnosis of depression and treatment should begin as soon as possible.
Successful aging or optimal aging is more than “choosing your parents wisely’. The MacArthur Foundation coined the term, “successful aging”. According to the researchers, we have the ability to age successfully. The key is a desire and means to sidestep disease, sustain mental and physical function and engage in actively in life.
Lifestyle choices, more than our genes, determine how we will age. Today’s common chronic diseases; arthritis, (an autoimmune disorder), heart disease and hypertension, (cardiovascular disease), and diabetes, (an endocrine system disorder) are related to the choices we make or to our beliefs. Our beliefs (stressors) can affect biological changes leading to chronic conditions and accelerated aging. Longevity is in a sense, our net ability to withstand the “sum of all our stresses” according to Dr. Reis in a recent issue of Geriatric Rounds.
Physiologist have known for more than fifty years that subjecting an animal to stress will cause it to age quickly. Researchers placed a mouse on an electric grid and administered mild shocks to it. The shocks do not have to be lethal to kill the mouse. By simply giving very mild shocks at random intervals, the mouse’s stress response was activated. When the stress response is called into play, the body focuses on the immediate survival and not rebuilding itself. Each time this happens, the body breaks down a little more. After only a few days of such stress, the mouse will die. Upon autopsy the mouse’s tissues displayed many of the signs of accelerated aging.
We need to learn how to handle stress, stop the cascade of hormones, especially cortisol, avoiding many chronic conditions and give our bodies time to recover between stressful events or suffer the fate of the mouse. One way of doing this is to take control of our lives by eliminating as many of the stressors as possible. Findings from the Berlin Study suggest perceived control over desirable outcomes is associated with high emotional well-being, where as perceived control by others is an emotional risk factor in old age.
Other forms of stress management or turning back the clock include exercise and meditation. Exercise enhances mood and blunts the stress-response. Meditation on a regular basis decreases cortisol levels, and sympathetic tone. Feelings of control, predictability, outlets for frustration, social connectedness, and believing things are improving rather than worsening are other ways to enhance the quality of our lives and the quantity of our years, reducing the effects of biological aging.
According to Henry Lodge, M.D, 50 percent of illness and accidents and 70 percent of aging problems can be prevented by following his “seven rules of nature.”
- Exercise six days a week.
- Do aerobic exercises four days a week.
- Strength train with weights for two days a week.
- Spend less than you make.
- Stop eating bad food.
- Care: care now for how well you want to be in the future.
- Connect and commit.
Deepak Chopra’s Ten Keys To Active Mastery and longevity are:
- Listen to your body’s wisdom.
- Live in the present.
- Take time to be silent.
- Relinquish your need for external approval.
- When you find yourself reacting with anger or opposition, realize you are only struggling with yourself.
- Know that the world “out there” reflects your reality “in here.”
- Shed the burden of judgment.
- Don’t contaminate your body with toxins, either through food, drink, or toxic emotions.
- Replace fear-motivated behavior with love-motivated behavior.
- Understand that the physical world is just a mirror of a deeper intelligence
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition. Washington, DC: 1994.
Callahan, Christopher M., et al. “Treatment of Depression Improves Physical Functioning in Older Adults. Journal of the American Geriatrics Society. Volume 53, no.3, 367-562: March 2005
Chopra, Deepak. Ageless Body Timeless Mind. New York: 1993
Colrera, Francesca. “Living Better, Living Longer, The Secrets of Healthy Aging.’ Harvard Medical School. Boston, MA: 2001. “Stress Control, Techniques for Preventing and Easing Stress.” Harvard Medical School.Boston, MA: 2002.
Cortidene Info. http://WWW.cortidreneinfo.com/cortisol.html (broken)
Digiovanna, Augustine Gaspar. “Human Aging.” Salisbury State University. Boston: 2000.
Fiske, Amy, et al. “Depressive Symptoms and Aging: The Effects of Illness and Non-Health-Related Events.” The Journals of Gerontology. Volume 58B, No. 6. November 2003.
Gambert, Steve R. “Depression: An Ongoing Clinical Challenge.” Clinical Geriatrics. Volume 12, no. 10, October 2004.
“Health Beat”. Optional Aging. Lodge, Henry, Crowley, Chris. News Channel 8. Tampa, Florida: April 12, 2005.
Kramlinger, Keith (editor). Mayo Clinic on Depression. Rochester, Minnesota: 2001.
Kunzmann, Ute, et al. ‘Perceiving Control: A Double-Edged Sword in Old Age.” The Journals of Gerontology. Volme 57 57B, no. 6, November 2002.
Medline Plus Encyclopedia. 2004. April 22, 2005. http://www.nlm.nih.gov/medlineplus/print/ency/article/003693.h (Broken)
Ormel, Johan, et al. “Temporal and Reciprocal Relationship Between IADL/ADL Disability and Depressive Symptoms in Late Life. The Journals of Gerontology. Volume 57B, no. 4, July 2002
Reis, Robert J.S. “Aging and Cancer”. Geriatric Rounds. The Donald W. Reynolds Department of Geriatric, College of Medicine, University of Arkansas for Medical Sciences. Volume 8, no.2, Spring 2005.
Rowe, John W., Kahn, Robert L. Successful Aging. New York: 1998.
Sapolsky, Robert M. Why Zebras Don’t Get Ulcers. New York: 2004.
Saxon, Sue V., Etten, Mary Jean. Physical Change & Aging. New York: 1994
Stoppler, Melissa, C. “Stress Hormone Levels Abnormal.” WebMD. http://stress.about.com/es/cortisol/a/aa122803.htm
“Cortisol, Stress, and Weight Gain.” WebMD. http://stress.about.com/cs/cortisol/s/cortweight.htm
“Cushing’s Syndrome.” WebMD. http://stress.about.com/cs/cortisol//a/CushNIND.htm
“Addison’s Disease.” WebMD. http://stress.about.com/cs/cortisol/a/AddNiddk.htm
“Cortisol:The Stress Hormone.” WebMD.http://stress.about.com/cs/cortisol/a/aa012901.htm
Turkington, Carol, Kaplan, E.F, “What is Depression.” WebMD http://my.webmd.com/conten/article/87/99351.htm
U.S. Government Printing Office. Federal Interagency Forum on Aging-Related Statistics. Older American 2004. Washington, D.C: November 2004.