Starting at what is commonly called middle age, operations of the human body become more vulnerable to daily wear and tear. There is a general decline in physical, and possibly mental, functioning. In the Western countries, the length of life often extends into the 70s. However, the upward limit of the life span can be as high as 120 years. During the latter half of life, an individual is more prone to problems with the various functions of the body, and to a number of chronic or fatal diseases. The cardiovascular, digestive, excretory, nervous, reproductive, and urinary systems are particularly affected. The most common diseases of aging include Alzheimer's, arthritis, cancer, diabetes, depression, and heart disease.
Human beings reach a peak of growth and development during their mid 20s. Aging is the normal transition time after that flurry of activity. Although there are quite a few age-related changes that tax the body, disability is not necessarily a part of aging. Health and lifestyle factors, together with the genetic makeup of the individual, determine the response to these changes. Body functions that are most often affected by age include:
- Hearing, which declines especially in relation to the highest pitched tones.
- The proportion of fat to muscle, which may increase by as much as 30%. Typically, the total padding of body fat directly under the skin thins out and accumulates around the stomach. The ability to excrete fats is impaired, and therefore the storage of fats increases, including cholesterol and fat-soluble nutrients.
- The amount of water in the body, which decreases, reducing the body's ability to absorb water-soluble nutrients. Also, there is less saliva and other lubricating fluids.
- Liver and kidney activities, which become less efficient, thus affecting the elimination of wastes.
- The ease of digestion, which is decreased, resulting in a reduction in stomach acid production.
- Muscle strength and coordination, which lessens, with an accompanying loss of mobility, agility, and flexibility.
- Sexual hormones and sexual function, which both decline.
- Sensations of taste and smell, which decrease.
- Cardiovascular and respiratory systems, with changes leading to decreased oxygen and nutrients throughout the body.
- Nervous system, which experiences changes that result in less efficient nerve impulse transmission, reflexes that are not as sharp, and diminished memory and learning.
- Bone strength and density, which decrease.
- Hormone levels, which gradually decline. The thyroid and sexual hormones are particularly affected.
- Visual abilities, which decline. Age-related changes may lead to diseases such as macular degeneration.
- A compromised ability to produce vitamin D from sunlight.
- Protein formation, which is reduced, leading to shrinkage in muscle mass and decreased bone formation, possibly contributing to osteoporosis.
Causes & symptoms
There are several theories on why the aging body loses functioning. It may be that several factors work together or that one particular factor is the culprit in a given individual. These theories include:
- Programmed senescence, or aging clock, theory. The aging of the cells for each individual is programmed into the genes, and there is a preset number of possible rejuvenations in the life of a given cell. When cells die at a rate faster than they are replaced, organs do not function properly, and they become unable to maintain the functions necessary for life.
- Genetic theory. Human cells maintain their own seed of destruction at the chromosome level.
- Connective tissue, or cross-linking theory. Changes in the makeup of the connective tissue alter the stability of body structures, causing a loss of elasticity and functioning, and leading to symptoms of aging.
- Free-radical theory. The most commonly held theory of aging, is based on the fact that ongoing chemical reactions of the cells produce free radicals. In the presence of oxygen, these free radicals cause the cells of the body to break down. As time goes on, more cells die or lose the ability to function, and the body ceases to function as a whole.
- Immunological theory. There are changes in the immune system as it begins to wear out, and the body is more prone to infections and tissue damage, which may ultimately cause death. Also, as the system breaks down, the body is more apt to have autoimmune reactions, in which the body's own cells are mistaken for foreign material and are destroyed or damaged by the immune system.
Many problems can arise due to age-related changes in the body. Although there is no individual test to measure these changes, a thorough physical exam and a basic blood screening and blood chemistry panel can point to areas in need of further attention. When older people become ill, the first signs of disease are often nonspecific. Further exams should be conducted if any of the following occur:
Consumption of a high-quality multivitamin is recommended. Common nutritional deficiencies connected with aging include B vitamins, vitamin A and vitamin C, folic acid, calcium, magnesium, zinc, iron, chromium, and trace minerals. Since stomach acids may be decreased, powdered multivitamin formula in gelatin capsules are suggested, as this form is the easiest to digest. Such formulas may also contain enzymes for further help with digestion.
Antioxidants can help neutralize damage caused by free radical actions, which are thought to contribute to problems of aging. They are also helpful in preventing and treating cancer, and in treating cataracts and glaucoma. Supplements that serve as antioxidants include:
- Vitamin E, 400–1,000 IUs daily. Protects cell membranes against damage. It shows promise in preventing heart disease, and Alzheimer's and Parkinson's diseases.
- Selenium, 50 mg taken twice daily. Research suggests that selenium may play a role in reducing cancer risk.
- Beta-carotene, 25,000–40,000 IUs daily. May help in treating cancer, colds and flu, arthritis, and immune support.
- Vitamin C, 1,000–2,000 mg per day. It may cause diarrhea in large doses. The dosage should be decreased if this occurs.
Other supplements that are helpful in treating agerelated problems include:
- B12/B-complex vitamins. Studies show that B12 may help reduce mental symptoms, such as confusion, memory loss, and depression.
- Coenzyme Q10 may be helpful in treating heart disease. Up to 75% of cardiac patients have been found to lack this heart enzyme.
The following hormone supplements may be taken to prevent or treat various age-related problems. However, caution should be taken before beginning treatment, and the patient should consult his or her health care professional prior to hormone use.
DHEA improves brain functioning and serves as a building block for many other important hormones. It may be helpful in restoring hormone levels that have declined, building muscle mass, strengthening bones, and maintaining a healthy heart.
Garlic (Allium sativa) is helpful in preventing heart disease, and improving the tone and texture of skin. Garlic stimulates liver and digestive system functions, and also helps manage heart disease and high blood pressure.
Siberian ginseng (Eleutherococcus senticosus) supports the adrenal glands and immune functions. It is believed to be helpful in treating problems related to stress. Siberian ginseng also increases mental and physical performance,
Ginkgo biloba works particularly well on the brain and nervous system. It is effective in reducing the symptoms of such conditions as Alzheimer's disease, depression, visual disorders, and problems of blood circulation. It may also help treat heart disease, strokes, dementia, Raynaud's disease, head injuries, leg cramps, macular degeneration, tinnitus, impotence due to poor blood flow, and diabetes-related nerve damage.
Proanthocyanidins, or PCO, (brand name Pycnogenol), are derived from grape seeds and skin, as well as pine tree bark. They may help prevent cancer and poor vision.
Green tea has powerful antioxidant qualities, and has been used for centuries as a natural medicine in China, Japan, and other Asian cultures. In alternative medicine, it aids in treating cancer, rheumatoid arthritis, high cholesterol, heart disease, infection, and impaired immune function. Several scientific studies have shown that antioxidant benefits are obtained by drinking two cups of green tea each day.
In Ayurvedic medicine, aging is described as a process of increased vata, in which there is a tendency to become thinner, drier, more nervous, more restless, and more fearful, while experiencing declines in both sleep and appetite. Bananas, almonds, avocados, and coconuts are some of the foods used in correcting such conditions. One of the main herbs used to treat these problems is gotu kola (Centella asiatica). It is taken to revitalize the nervous system and brain cells, and to fortify the immune system. Gotu kola is also used to treat memory loss, anxiety, and insomnia.
In Chinese medicine, most symptoms of aging are regarded as signs of a yin deficiency. Moistening foods are recommended, and include barley soup, tofu, mung beans, wheat germ, spirulina, potatoes, black sesame seeds, walnuts, and flax seeds. Jing tonics may also be used. These include deer antler, dodder seeds, processed rehmannia, longevity soup, mussels, and chicken.
For the most part, doctors prescribe medications to control the symptoms and diseases of aging. In the United States, about two-thirds of people age 65 and over take medications for various conditions. More women than men use these medications. The most common drugs used by the elderly are painkillers, diuretics or water pills, sedatives, cardiac medications, antibiotics, and mental health remedies.
Estrogen replacement therapy (ERT) is commonly prescribed to alleviate the symptoms of aging in postmenopausal women. It is often used in conjunction with progesterone. These drugs help keep bones strong, reduce the risk of heart disease, restore vaginal lubrication, and improve skin elasticity. Evidence suggests that they may also help maintain mental functions.
Aging is unavoidable, but major physical impairment is not. People can lead healthy, disability-free lives throughout their later years. A well-established support system of family, friends, and health care providers, along with a focus on good nutrition and lifestyle habits, and effective stress management, can prevent disease and lessen the impact of chronic conditions.
Preventive health practices such as healthy diet, daily exercise, stress management, and control of lifestyle habits, such as smoking and drinking, can lengthen the life span and improve the quality of life as people age. Exercise can improve appetite, bone health, emotional and mental outlook, digestion, and circulation.
Drinking plenty of fluids aids in maintaining healthy skin, good digestion, and proper elimination of wastes. Up to eight glasses of water should be consumed daily, along with plenty of herbal teas, diluted fruit and vegetable juices, and fresh fruits and vegetables that have a high water content.
Because of a decrease in the sense of taste, older people often increase their salt intake, which can contribute to high blood pressure and nutrient loss. Use of sugar is also increased. Seaweeds and small amounts of honey can be used as replacements.
A diet high in fiber and low in fat is recommended. Processed foods should be replaced by such complex carbohydrates as whole grains. If chewing becomes a problem, there should be an increased intake of protein drinks, freshly juiced fruits and vegetables, and creamed cereals.
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The Anti-Aging Institute. 843 William Hilton Parkway, Hilton Head, SC 29928. (912) 238-3383. <http://www.anti-aging.org>.
The Rosenthal Center for Complementary and Alternative Medicine Research in Aging and Women's Health. Columbia University, College of Physicians and Surgeons, 630 W. 168th St., New York, NY 10032. <http://www.rosenthal.hs.columbia.edu>.
National Institute on Aging Senior Health Web site. <http://www.nihseniorhealth.gov>.