Most of us know that our physical and mental abilities change as we age, but not many of us know exactly why. The short explanation is that, just like a car, parts naturally wear out over time. The longer explanation is an interesting look at human biology.

Gerontologists at the National Institute on Aging (NIA) study the differences between normal age-related changes and disease-related changes. They have found that normal changes, including hearing loss and a reduction in brain volume, occur even among healthy older people.

Over time, aging affects the cells of every major organ of the body, which is what causes these changes. For example, lung tissue loses elasticity and causes us to get “winded” more easily. Digestive enzymes decrease, affecting our ability to properly absorb nutrients and putting us in danger of malnutrition. Blood vessels in the heart lose flexibility, causing the heart to work harder, often resulting in high blood pressure.

Bones and muscles are also naturally affected by age. According to the Mayo Clinic, bones tend to shrink in size and density, making them more susceptible to fracture and causing us to lose height. Muscles lose strength and flexibility, which causes a decrease in coordination and trouble with balance.

Aging also affects our eyes and ears. We naturally become more sensitive to glare, have trouble adapting to different levels of light and have trouble reading small print. Hearing is also diminished, and we have difficulty hearing high frequencies or following a conversation in a crowded room.

Urinary incontinence is another common complaint in older adults, and can be brought on by menopause in women and an enlarged prostate in men.

Our skin gets thinner and less elastic with age, causing more sores and bruising. Decreased production of natural oils can also make skin drier.

A decrease in taste and smell is also natural with aging, often leading to decreased appetite and poor nutrition. It can also cause a temptation to use excess salt or sugar, which can aggravate high blood pressure and diabetes.

Perhaps of greatest concern to older adults, is a decrease in memory. It can bring with it a fear of dementia and Alzheimer’s disease.

Publications are available from The Alzheimer’s Association (800-272-3900) that compare normal age-related memory symptoms with memory symptoms that may indicate something more serious.

The Mayo Clinic and the NIA both agree that maintaining good health can reduce the severity of age-related changes. They report that physical activity, a healthy diet, stress management, abstinence from smoking and excess alcohol, and staying mentally and socially active can help keep us as healthy as possible as we age.

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