How Aging Affects Your Body
Seniors' Health
Last updated on (January 5, 2000)

Introduction --

No one can turn back the clock, but research shows that we can ameliorate many of the effects commonly associated with aging to prevent or delay the young-old from becoming the frail and disabled. For example, muscle tone is directly related to how much muscles are exercised. In the absence of disease or disability, if we continue to exercise into old age, muscles will not -- as is commonly believed -- weaken and atrophy with age. Lack of use can cause the muscles of adolescents to weaken and atrophy, and too often does. Indeed, research shows that the muscles of the aged can work as well as those of the young. Even a fitness program established in the later years can be quite beneficial.

Here is a general overview of what happens to the various areas or systems of the body as the years progress: Aging is not isolated but systemic, that is, it affects the whole body. Loss or disuse in one area is echoed in other areas. Diminished estrogen production after menopause, for example, effects the absorption by the bones of calcium, leading to osteoporosis; it also affects heart health, sometimes leading to impaired circulation and coronary heart disease. These, in turn, affect all other bodily systems.

These "separate" areas are therefore listed that way simply for convenience and clarity's sake. The rates of aging of the bodily systems will vary considerably from person to person. Everyone except identical twins has a different genetic makeup, and everyone has been exposed to different environments. All of us have different lifestyles, and so different parts of different people will show the effects of time at different rates. Age, after all, is time related, and we cannot change that. One 70-year-old may have the heart more typical of a 40-year-old and the skin more typical of a 90-year-old.

1. Skin, Muscles, and Connective Tissue --

As we get older, our skin generally thins, loses some of its blood supply and its collagen (the fiber that gives young skin its tautness) and becomes less resilient and more dry. The skin loses some of its ability to do its job: it sweats less and reduces production of natural skin oils. Diminished moisture is more or less universal throughout the body. Hair becomes thinner. Wrinkles and blood vessels become more apparent as the layer of fat beneath the skin diminishes. Wrinkling and other skin changes are more pronounced in those who have spent a lot of time in the sun or were smokers. Loss of fat has a number of ramifications. Body fat helps provide a cushion so that we do not bruise as easily and helps us keep warm. It also affects hormone levels and the way alcohol and other drugs are metabolized. For example, research shows that the effect of one glass of wine on a senior is the same as two glasses on a younger adult.

Loss of muscle, if it occurs, is caused by lack of use, a disease affecting muscle or nutritional deficiency. Research shows that the muscles of the elderly may have a slightly reduced rate of blood flow but remain as efficient in their use of oxygen as those of younger people. The presence of arthritis or another chronic illness, or obesity, can lead to a sedentary lifestyle, which in turn can lead to muscle atrophy.

The cartilage that acts as the cushion and connection between our bones can lose some of its capacity to withstand repetitive impact. Because it has no blood vessels and so depends on blood supply from the surrounding tissues for its nourishment, it can become less resilient with aging.

2. Bones and Teeth --

Osteoporosis has become well known as one of the common effects of aging, and indeed, loss of bone density is a problem with lasting consequences for both men and women. Several different factors account for loss of bone density. First is loss of sex hormone production. Estrogen is markedly reduced in women at menopause. Testosterone levels decline slightly in men as they age, but levels decline more dramatically when testosterone production is compromised by illness or alcoholism. The significance of this decline, however, is unknown, and lower levels of testosterone don't necessarily mean that a loss of libido is inevitable. In addition, lower levels of testosterone do not lead to erectile dysfunction. Other causes of bone density loss include lack of exercise, the use of certain medications and poor nutrition. Osteoporotic bones are weaker and fracture more easily than strong bones. Fractures can lead to severe limitations in physical mobility and can threaten an independent lifestyle.

Bone marrow -- which produces the white blood cells that fight infection -- diminishes with aging, while marrow fat increases. This does not, however, appear to cause the marrow to be significantly less productive or active. White blood cell counts remain largely unchanged throughout life, and white blood cells retain their ability to fight off bacterial infection.

Although anemia (a deficiency in red blood cells and hemoglobin) is often associated with aging, it is not caused by the loss of capacity of the body to produce red blood cells; rather it is due to other problems, most prominently undernutrition, disease or decreased production of hormones that regulate bone marrow activity.

Dental problems can be a direct cause of poor nutrition. The same circumstances that can lead to osteoporosis and weakening of the bones can also lead to weakening of the teeth.

3. Circulation --

The functioning of the heart does not seem to be significantly diminished by the passing of time itself, and yet cardiovascular disease is the most common cause of death in this country. Many women worry about breast cancer, without realizing that death from heart disease is far more common. Cardiovascular disease on average tends to affect women later in life than men. For reasons not fully understood, the hormone estrogen appears to provide women with protection. After menopause, women are as vulnerable as men to heart disease, due to the narrowing of blood vessels caused by the buildup of plaque deposits that can result in decreased blood flow and increased blood pressure. For men and women alike, diet and exercise can help prevent heart disease.

The body's vasculature may lose some of its suppleness, and varicose veins may develop. Some difficulty in circulation to the limbs may occur. Again, however, exercise and diet have been shown to help maintain good circulation.

4. Lungs --

The catch phrase "use it or lose it" is true of muscle mass as well as bone density, and it is also true of lung capacity. Like virtually every other body tissue, lungs can lose some elasticity as we age. They appear to gain volume while losing some of their inner surface area and therefore some of their ability to absorb oxygen from the air we breathe. But research shows that exercise can increase the ability of the lungs to do their job and further demonstrates that seniors who are in good shape already can frequently surpass many young people in lung function. While the ribs and breastbone can fuse, forcing the diaphragm to work harder, loss of lung function does not have to be an inevitable part of aging. The diaphragm does not seem to be adversely affected by normal aging.

Smoking speeds deterioration of the lungs and produces a great amount of heart and lung disease. Stopping smoking now -- at any time -- can reduce the risk of many heart- and lung-related illnesses.

5. The Gastrointestinal Tract --

Although the gastrointestinal tract remains quite resilient throughout life and does not lose its ability to do its job, there can be some reduction in the capacity of the muscles of the gastrointestinal tract to coordinate their movements. This can lead to constipation, a common problem among seniors. The contractions that take place in the upper gastrointestinal tract during swallowing can also weaken and become less well coordinated, which can lead to gastroesophageal reflux, commonly associated with heartburn. Over time, the production of gastric juices (hydrochloric acid and pepsin) and saliva tend to decrease. The rate at which different vitamins and minerals are absorbed in the gut can also change over time. Because the ratio of body fat to body water increases as we age, those compounds that are fat soluble, such as vitamin A, may have more rapid absorption and metabolization, while those that are water soluble may not be used as efficiently. Changes can also take place in the way we absorb minerals, particularly calcium and iron.

By compensating with dietary changes and thorough, careful chewing and swallowing, you can enable your digestive tract to work well throughout life.

Another common characteristic of bowels in aging persons is the formation of diverticula in the large intestine. These small, pouch-like formations can result from increased pressure on the walls of the bowel and decreased resilience of the muscles. The disorder can be present in as many as a third of seniors. Often completely harmless, these diverticula can become inflamed when bits of stool lodge in them and cause infection.

6. Other Vital Organs --

Our organs, when we are young, function at a level several times in excess of what is needed in order to do their jobs. As we age, many of our organs gradually lose some of their ability to function to full capacity. Each organ ages at a different rate and differently in each person. The kidneys gradually lose some function but for the most part are able to maintain the delicate balance of water, electrolytes and other substances in the blood. Loss of organ function may affect the way your body metabolizes certain vitamins. You should check with your doctor to see if you need more or less of particular vitamins.

The liver becomes somewhat smaller over time and loses some of its blood supply; it is also less capable of renewing damaged tissue. However, the liver should work well throughout life. This is also true of the pancreas, which should work well throughout life, although its position in the body can shift slightly, and it can pick up fat and scar tissue as you age.

Glands of the endocrine system, such as the thyroid, adrenal, pituitary and hypothalamus -- all of which produce necessary hormones -- slow down their output by varying degrees. Loss of hormone production can cause a reduction in overall metabolic rate, but noteworthy loss of function in hormone-producing glands is usually associated with serious disorders, such as diabetes, and not the normal aging process. Adult-onset diabetes is usually caused by obesity and lack of exercise, not by aging.

7. Genitourinary and Reproductive Function --

Men can continue to father children well into old age. Some men, however, experience some kind of transient or chronic impotence, loss of sexual desire or other impairment of sexual function. This, however, is not a natural consequence of aging but usually is due to illness, such as diabetes mellitus, certain medications or depression and can be treated. Because of neural changes, aging is likely to cause some slowing down of sexual response. Despite this, most seniors should be able to continue an active and satisfying sex life throughout life; indeed, it appears that seniors who maintain a healthy sex life are at an advantage for retaining better genitourinary health.

In men, the prostate often becomes enlarged as time passes, and this can cause some urinary and sexual difficulty.

In women, loss of tone in the muscles that govern urinary function can result in incontinence. Incontinence is not an inevitable part of aging, though television commercials for adult diapers may imply otherwise. Incontinence is associated with disorders such as atrophic vaginitis in women or chronic neurologic disease in both men and women. However, lost muscle tone, which is particularly common in women, can almost always be regained with prescribed exercise. About 85 percent of women who are ambulatory and not neurologically impaired can be cured of urinary incontinence or dramatically improved. Both women and men who have incontinence can be helped, so you should discuss the problem with your doctor. If your doctor is not experienced in this problem, many communities have incontinence assessment and treatment programs.

After menopause, estrogen production diminishes. In the absence of sufficient amounts of the hormone, which you can take supplementally, the vulvar region tends to atrophy, with loss of pubic hair and shrinkage of the labia majora. The labia minora can almost disappear. Certain chemical changes alter the pH of the vagina and lower resistance to some types of infection. The vagina can lose its interior folds and elasticity. An active sex life appears, however, to mitigate these changes.

Even before menopause, the milk-producing glandular tissue in breasts diminishes; menopause causes it to atrophy. Women may notice that their nipples become, over time, smaller and less likely to become erect. Estrogen supplementation may prevent these age-related changes in breast tissue.

8. Central and Peripheral Nervous Systems --

The nervous system includes three interacting systems: the central nervous system, or the brain and spinal cord; the peripheral nervous system, which consists of the cranial nerves and spinal nerves; and the autonomic system, which controls the automatic functions of the body, such as breathing and heart rate. With age also comes a slowdown in the rate at which nerves are able to transmit signals to one another. This can affect some types of thought as well as some reflexes and can include a slower response to new information -- learning may take more time, but you can do it -- and changes in sleep patterns. Forgetfulness may increase slightly, but it is more likely that seniors notice forgetfulness more than younger people do. As with muscles and bones, there is a "use it or lose it" mechanism to mental acuity. Just as those who stay physically active tend to stay physically vigorous, those who stay mentally active (taking courses, keeping up with current events) tend to remain mentally vigorous.

For the most part, despite the association of senility with aging, the profound loss of mental acuity is a symptom of a disorder and not a part of the normal aging process.

9. Senses --

As all other bodily systems lose some of their youthful edge, so too can the abilities to see, hear, taste, feel and react lose some of their acuity. Often, these are not profound changes. They happen only gradually, and perhaps without our noticing; the pupils of our eyes, for example, do not contract as rapidly as we age. And many of the changes that result from disorders -- cataracts, hearing loss -- can be treated quite effectively. Reaction time can diminish as well, and many states now require seniors to undergo driving tests more frequently than younger people. Losing driving privileges can come as a heavy blow to many and represents a considerable loss of freedom -- but that loss hardly compares to the potential for loss in automobile accidents. With a positive attitude and some help from family and local agencies, you should still be able to maintain freedom.

Conclusion --

Most of the changes listed above are quite gradual in their onset, and many can be quite easily offset by appropriate exercise, sensible diet and appropriate medical treatment. Others, however, are simply facts of life -- but that does not mean that we have to let them turn us into invalids or shut-ins. There are ways to live around and through these changes in order to maintain a high quality of life.