The human life span has been growing dramatically. A person born in 1776 could expect to live 35 years. By the year 1900, the average life span was only 47 years. Today, a female born can expect to live 79 years, and a male 72 years. Those who live to older ages than these have a greater life expectency! A woman over 65 could very likely expect to live another 18 years on average. A woman who lives to 85 will average another six years of life!
Predictions on Aging
Can this trend continue, with people getting older and older? Not likely, say experts. In the early part of this century, life expectancy was due to decreases in infant mortality rate and advancements in public health. However, it has become more difficult to improve the survival rates of those who suffer chronic diseases. Sadly, these have dominated modern times, leaving the life expectancy flat over the past decade. Most aging experts feel the human life span will not extend much past 85 years of age barring any major breakthroughs in the biology of aging.
Most people, if asked if they would like to live to the age of 100 say "no!", unless they can remain active, healthy and mentally sound. Without those quailities in life, is it worth adding years? Most of us feel it is far better to add life to the years instead.
Can We Alter the Aging Process?
Is it realistic to hope we can affect our aging process? A common line of thinking is that our life expectancy is in our genes. Many feel this so strongly, they do not feel bad habits will make much difference in their destiny.
Many scientific studies looked at the aging processes of twins reared together and apart to look at the contributions of genetics vs. living habits to longevity. Two famous twins' studies found that aging was less related to genetic factors than to lifestyle and health behaviors. What this tells us is, there is much evidence to suggest we can affect our aging process with better lifestyle habits/choices.
Theories as to Why We Age
No one truly understands why we age. There are over 300 theories proposed for the biological basis of aging. Many of those theories fit into two categories. The first is called stochastic. Basically, this states age is a result of random damage to cells and organs with the progression of time. The second category states aging and the death of our cells is in fact, genetically determined. This theory is referred to as that of programmed theories. Let's touch on theories a bit more.
The Stochastic Theory
Free radical theory: This is the most prevalent of the stochastic theories. This theory recognizes that metabolic reactions occur continuously in the body. This process produces unstable molecules we call free radicals. Free radicals try to stabilize themselves by a process called oxidation. This process damages elements of cells such as protein and DNA. In short, this theory states oxidants as teh perpetrators of aging. Our bodies have many natural means of anti-oxidant defense, among them are vitamin C, vitamin E and vitamin A. In addition, there are many antioxidants touted for anti-aging effects, The claim, or belief, is that they combat free radicals.
Caloric Restriction Theory
Another view, associated with the free radical theory, is the theory of caloric restriction. Proven in many species of animals to result in extension of life expectancy, this theory is based on the thought that reducing the metabolism of calories reduces oxidative damage to our cells. Currently, experiments continue with primates and with humans. Just how much caloric deprivation is still unknown. In animals, the caloric restriction which appears to achieve results is a 40 percent reduction in caloric intake. To follow this line of thinking, ask yourself if you are willing to give up 40 percent of what you eat to extend your life. In today's society, we do eat more than required for optimal health and nutrition so this may not be a bad concept to follow but again, many variables come into play depending on what it is you eat and what you give up!
We do now know without doubt, obesity contributes to many premature deaths due to complications. However, on the flip side of that, is has not been proven thin people live the longest. Too thin can mean illness or undernourishment, as well.
General indications to go by:
The lowest morality rates are in those with a body mass index (BMI) in the range of 21 to 22. To calculate your BMI, see the chart on this site, or jot down this formula:
- Convert your weight in pounds to kilograms by dividing your weight in pounds by 2.2.
- Multiple your height in inches by 0.0254 to get your height in meters.
- Multiply your height in meters by itself.
- Divide the answer to number 1 by the answer to number 3.
The Hormonal Theory
Another theory of aging has caused much interest in the healthy aging movement. It is the hormonal theory of aging. Numerous hormones, chemical substances secreted by various glands in the body, decline with aging This is leading experts along the line of thought that replacement of these hormones may prevent the aging process.
Hormones that are currently considered a means of combating aging. Among the hormones under study are: DHEA, melatonin, testosterone, and estrogen. Many people currently take growth hormone injections and enthusiastically ingesting other hormones in the hope of increasing life span, but is their sufficient evidence to support this enthusiasm? The answer remains to be seen. In an exciting study in 1990, human growth hormone proved to increase muscle mass and bone density, as well as decrease fat in aging men.
Since then, many studies evaluated its efficacy in reversing aging in malnourished, frail, elderly, and critically ill persons. The results are mixed. Furthermore, this approach can only be given by injection. Consequently, it has many potentially serious side effects like hypertension, heart failure, and diabetes. It is terribly expensive as well. The price tag for weekly growth hormone injections can be as much as $15,000 annually.
Testosterone, Melatonin, DHEA, and Estrogen
Similar questions remain about the long-term effectiveness of other hormones. Testosterone definitely improves sexual performance in testosterone-deficient men. It can help control hot flashes and increase libido in postmenopausal women, and may increase strength in frail elderly. However, long-term effects are not known, and there is a concern about testosterone promoting the growth of prostate cancer.
Melatonin aids in the regulation of sleep, especially in jet-lagged travelers, but whether or not it can truly reverse aging and prevent cancer as promised is not been proven.
DHEA, a hormone produced by the adrenal gland but also found in plants, does not have significant evidence to show it reverses aging, or increases strength, energy, or libido, although some small studies suggest that it may help decrease depression.
In short, there are no definitive answers regarding these highly-touted hormones. The only hormone validated by many scientific studies to prolong survival is estrogen. It improves survival in women, especially those with risk factors for heart disease.
In a study done in Boston to determine what helps people live a long and healthy life, there were several personal attributes were common to the majority. Those were:
- Low levels of depression
- Striking ability to cope with, and adapt to, stress and loss
- High levels of intellectual stimulation
- Frequent use of humor as a coping mechanism
- High levels of social interaction and support
- Nearly universal lack of obesity, excess alcohol, and smoking
Can we learn from this? Yes! Is it possible to ward off the ravages of time? To a large extent, yes. Promising approaches to extending health and active, independent function into the latest years include:
- Preventing diseases
- Reducing cellular damage
- Avoiding aging caused by disuse
- Genetic manipulation (potentially)
There are ways to prevent the fragilties of aging, and to promote active, independent life, into late life. It is more in your hands than you may have thought!
You may also find of interest...
- Incredible Instant Anti Aging Discovery
- Stay Young, Naturally
- Can We Train our Memories?
- Meditation for Seniors
Disclaimer: The material on this Web site is not intended to replace advice from your doctor or fitness professional. Please consult with your physician before beginning any fitness program or fat or weight reduction program. FitnessandFreebies.com takes no responsibility for individual results, or any claim made by a third party.