Many of the common sayings and beliefs about growing old have had to be revised in the light of new information that has been developed by medical science in the last twenty years. We used to say that a man is as old as his arteries. Now we realize that changes in the arteries may go on without aging if all the rest of the body. A man is as old as skin, his adrenal glands and his nervous system, even more than his arteries. Aging shows up most obviously in the skin and in the brain.

Old people suffer from nutritive deficiencies that result chiefly from economic, psychological, or physical problems. Degenerative changes, formerly accepted as routine, are now considered controllable to some extent by means of improved nutrition and  by the administration of glandular substances; the latter are used particularly to prevent degeneration of the sex glands. Premature loss of the estrogen (the female sex hormone) or testosterone (the male sex hormone) can cause fine wrinkles, loss of hair, and other obvious manifestations of aging. Experimental studies indicate that treatment with hormones can somewhat delay senescence.

Changes can go on in the tissue of the human body at varying rates. Some require a long time and others occur rapidly. Hardening of the arteries is a slow process and is therefore seen most frequently in the aged. Actually the human being has a life cycle of about seventy years and barring accident or other stresses will probably live that long. During his seventy years the human being is subjected to a good deal of wear and tear. This may include excess of food, drink, or narcotic substances. The wear and tear may include infections, bad weather, accidents while at work, overwork, boredom, or emotional upsets. Even without excessive wear and tear, however, the tissues gradually lose their ability for growth and repair and we grow old. Pathologists talk about atrophy of disuse. At certain ages both women and men lose their ability to reproduce, which is a function of youth and middle age.

Actually the blood vessels carry on longer than most other tissues of the body. Operations are done on very old people and they recover with blood supply flowing into the area that has been shut off by the operative procedure.

For the aging process doctors use the word involution. The loss of ability to read small type as one grows older is associated with changes in the tissues of the eye. As our tissues age, they tend to recover less rapidly from disease or injury. The aging heart beats with a little more trouble than does the young heart. Modern medicine has learned to substitute for some of the disappearance of tissues and their secretions. We give liver extract in forms of anemia, insulin for diabetes, eye glasses for visual disturbances and canes or crutches for weakening muscles.

Disappearances of neurons or nerve cells in the nervous system come on with age. This helps to make old people less agile than the young and less capable to carry on hard work for a long time. The tremors of old age are accredited to similar loss of neurons.

Old people do not observe as acutely as do the young. They do not remember recent events. Eventually the loss of tissue from the aging brain may reveal itself in apathy, irritability, or stolidity. Many old people talk and talk and talk. This garrulousness may be accompanied by too great a concern over little, unimportant things and less concern about essential problems.

Doctors have learned that the accounts old people give of their symptoms, the trials and tribulations, neglects and concerns of their families, are not quite as dependable as were accounts by these same people given when they were younger.

Actually old age needs lots of sympathetic consideration from the young. Read the ages at death of the people in your community. You will discover great numbers of sixty-five, with only here and there one from fifteen to fifty. The span of life has changed and we must learn to accommodate ourselves to it.

In vocabulary, comprehension, and arithmetic only a slight difference is found between the scores made by people in their thirties, the period when their abilities in these areas are highest, and the scores made by people 70 years old. This special study of older people, supported by the Committee on Human Development, University of Chicago, and by the US Public Health Service, was carried out in Kansas City concurrently with the national standardization of the same intelligence test for adults 16 to 64 years of age. For performance, maximum scores are attained by people in their twenties; performance falls of after age30 with gradual decrements up to age 70, and with marked lowering after that age. Performance tests place a premium on visual acuity, speed and manual dexterity. Substantial retention of verbal and communication abilities far into old age, is of special significance and is likely to have considerable practical importance in shaping attitudes about and planning programs for older people.

This information was taken from the New Illustrated Medical and Health Encyclopedia.