Disorders of aging

The average life expectancy has increased dramatically in Nigeria. A male child born in 1900 could expect to live for only 46 years, whereas one born today can expect to live more than 72 years. A female child born in 1900 could expect to live for 48 years according to Prof. E.H. Parry of Ghana a professor of medicine Ahmadu, Bello University Zaria. Whereas a woman born today can expect to live for 79 years.

Despite the increase in average life expectancy, the maximum life span – the oldest age to which people can,  has changed little since records have been kept . Despite the best genetic makeup and medical care, no one seems to live much beyond 100 years.

The process of aging begins in the middle to late twenties, and continues till death. No one escapes its effects but there are often great differences in its degree of impact on people of same age.

The efficiency of a man’s body functions at the age 75 is proportionately less than at 30. 

Changes in facial appearance come about in adulthood through atrophy of the facial bones, recession of the gums, and loss of teeth. The skin becomes dry and loses its elasticity, taking on a wrinkled appearance. This deterioration is speeded by the loss of fat deposits from under the skin surface. Hair becomes grey as pigment ceases to be produced. Also both sexes undergo loss of hair though actual balding is much more common in men.

Full stature is reached by the age of 20 or shortly afterwards. After that, there is little change in the size of any individual bones. However adult height does decline with the aging process. This is partly because the vertebrate discs in the spine deteriorate, causing the spine to shorten slightly. But more important is the gradual weakening of the body muscles so that the spine is not held so erect.

Medical science can prolong the life-span- but it cannot yet prolong youth. Gerontology- the serious study of aging is still a new science, and even the process and causes of aging are not yet properly understood.

Cell mutation is currently thought of as the main cause of aging, most cells in the body reproduce to replace cells that have died.

They do so by “somatic division” i.e by dividing into two. In this way the exact characteristics of the original cell are preserved. However it is possible for mutation to occur in the cell. This is any form of damage affecting the chromosomes, which are the code system built into the cell that decides how it operates.

Mutation can be caused by the gradual exposure over a lifetime to natural radiation from the Sun or naturally occurring isotopes. Less normally, it may also be caused by disease, chemical action; or radiation from nuclear activity, exposure to x-rays etc.

When mutation occurs, a cell may become inactive or do its job badly or be actively dangerous as in the case of cancer.

Moreover because chromosomal damage is involved, the distortion is passed on whenever the original cell reproduces. A somatic division means that the number of mutated cells increases in geometric progression 1,2,4,8,16,32,64. In this way, areas of the body’s activities become inefficient or disrupted. The effect is increased when the process occurs in certain organs eg in the endocrine glands which form the body’s chemical control system.

From the age of about 25, there is a continuous loss of nerve cells (neurons) from the brain and spinal cord. These cells cannot be replaced once lost, and the rate of neuron loss is accelerated in age by the onset of arteriosclerosis.

Some other factors have been seen to play a part in aging but they are not “causes” in the same sense as cell mutation and nerve cell loss are thought to be.

Psychological stress often has physical manifestations and it has been noticed that stress of all sorts, physical danger, pain mental strain etc can cause premature aging. However, the biological process whereby this happens is not known.

   As a person grows older, there is a drop in his basal metabolic rate: That is, the energy production of his body at its lowest waking level. For example, the body temperature of an old man is on average 1*C less than that of a 25 –year – old.   Metabolic decline is a sign of the aging process, rather than a cause, but it has a wide impact on the body’s function and abilities.

   During the female menopause, the ovaries stop producing oestrogen and male production of testosterone also declines after the middle years – though it never reaches zero level. It was therefore natural for gerontologists to consider using injections of the appropriate hormone to make up the body failing supply. 

   However, although injections of these hormones can reduce some physical sign of aging, smooth out wrinkled skin for example, they do not seem to prevent the basic physiological process of aging going on. In general, hormonal decline seems to be one of the ways in which aging expresses itself, but not a basic cause.

   Muscles lose strength, shape and size. Joints become worn and lose their ease of articulation. Combined with the degeneration of the nervous system, ease and confidence of movement is lost from the bones, it tends to be deposited in other areas – especially the walls of the arteries and the cartilage of the ribs. This causes lost of elasticity.

   One effect is lowering of lung capacity. Most internal organs such as the liver, heart and kidney – become reduced in size and function. The arteries harden and narrow (arteriosclerosis). This increases the normal rise in blood pressure, which goes up about 0.5mm Hg, a year from the onset of aging.

   The speed of blood flow also rises – though usually not excessively. When arteriosclerosis is combined with atheroma, degeneration of the arteries inner lining, the condition is known as atherosclerosis. These disorders of the vascular system, speed up tissue decay, through inadequate blood and oxygen supply. This especially affects the heart and brain.

   The decline in efficiency of the body also affects an aging persons physical strength, conscious capabilities, nervous control and mental powers, maximum measures in these are mostly reached at different ages from 20 to 30.

   Changes in temperament and behavior in old people may be accepted as inevitable. But how far they are really due to neurological and mental deterioration is often hard to judge. 

   The changes may rather be a psychic reaction to the person’s social, psychological and physical situation.

   Old age often brings with it a dramatic change in a person’s experience of life. Declining physical ability, and efficiency perhaps involving being looked after by others, the end of the working life; and isolation, due to the disappearance of work contacts, family mobility and death of friends – all these can affect an old person’s self esteem; and lead to depression and melancholia.

   Old people find that they have no role to fulfil and no social label, or way of identifying themselves, other than by that term “old person” – the associated stereotypes of which are not inspiring. 

   Society’s subtle message can seem the same, you are no-longer really useful and though you are enjoying the deserved fruits of your labour, your difficulties and In capabilities are something of a problem for us.

   Of course, many old people keep up a wide range of activities – but for others it is difficult, due to lack of finance, isolation, physical incapacity, and lack of mental stimulation.

   The rate of change in modern society adds to their disorientation, and the way of life in many old people’s homes does little to help. All this can result in apathy, listlessness, resentment and mental stagnation, which others then dismiss as inevitable senility.

Always be medically guided.

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