The Natural Process of Aging

                                                         The Natural Process of Aging - Article

Everybody knows old people are more likely to die than young people. We know it from experience. We can find the facts
and figures in life insurance tables. For Example, in a well-fed, advance country only about one in every 1,000 children dies
during his or her 12th year. But one in every 20 men aged 70 will die before his 71st birthday.

The risk we run of dying at any particular age is called the force of mortality for that age. The force of mortality has been
carefully worked out for all ages of people -this is what life insurance rates are based on. Naturally, it grows steadily greater
with age. If we kept all through life the same force of mortality that we had at 12- never becoming any more likely to die that
we were then- years, unless we were very unlucky or careless. The fact that people do not live several hundred years (and
only rarely reach 100) is due to a process called aging.

We can recognize aging by the gray hair, weakened muscles, wrinkled skin, loss of hearing, and other signs that it
produces. It also has a more important effect on us. It reduces our power of staying well and of getting better if we fall ill. A
head cold may not be serious in a young person, but it complications may lead to death in an old person.

This loss of power to stay healthy (and the increase in the likelihood of dying) happens at about the same rate in everybody.
As we get older, we tend to be like and old radio or an old automobile. - more and more things go wrong with us. There
comes a time beyond which it is very difficult to stay alive at all. The least thing may be enough to finish us. This is the end
of our life span.

                                                         AGING IN MEN AND WOMEN

People and other animals that age have fixed life spans, or characteristic ages of death. Some individual may died sooner,
while strong or lucky ones live longer. But most individuals of a species have about the same length of life. In countries with
good food and medical services, the most common length of life in people is between 70 to 80 years. Where there is hunger
or little medical care, many people die young. Often dead among babies, or infant mortality, is very high. For those who
survive, expectation of life is low -perhaps 40 to 45 years.

Women for reason we do not yet understand, live a little longer on the average than men. Some people, especially if they
have come from long-lived families, live longer than others. Some are able to live as much as 20 years beyond the usual
limit of life. For example, here are the figures for England, Canada, an the United States. In these countries about three out
o every 100 babies born will live to be 90 years old; about one out of every 1,000 will live to be 100.

A few people live longer still, up to 107 or 108 years. There is a great deal of argument about the highest age ever reached
by a person.

Probably it is just short of 120 years. For instance, a man who said he was 117 and the last survivor of the confederate
Army died in Texas en 1959. People who have claimed to be older than 120 have never been able to prove it. Some old
people are jokers who tell tremendous tales about their age. Other people are willing to believe these tales because they
like the idea of living a long time.

                                                               AGING IN ANIMALS

We are used to the idea that we will age. We are so used to this that it comes a surprise to find that there may be some
animals that do not age. Sea anemones are an example. Some have been kept for nearly a century without showing any
signs of losing vigor. Some kinds of marine worm can even “grow backwards”. If starved and kept in the dark, they get
steadily smaller. They finally end as a ball of cells, looking rather like the egg from which they came. Under favorable
conditions the ball will turn back to a worm and start growing again. One could probably keep them growing and “un-
growing” indefinitely.

An animal that does not age is not immortal. That is, it is not deathless. Some individuals will die by accident or from
disease every year. But such animals do not get more likely to die with age. The force of mortality stays the same in them.

It is sometimes said that small wild animals and birds do not age. What really happens is that they do not have a chance to
age. Nearly all die by accident before they have a chance to get really old. Few small birds in the wild survive more hat a
couple of years. But in the cage, protected from hunger and enemies, they can live as long as 20 years and then die of old
age.

Most animals are like us in having fixed life spans. Birds live longer than mammals of the same size. Fish and reptiles, which
are cold blooded, live longer still. Not only do they live long but, unlike us, they keep growing. An English ship once caught a
halibut about 3 meters (10 feet) long. Experts could tell from its scales that it was more than 60 years old. The fish was full of
eggs and still growing. At one time it seemed that because they go on growing, these big fish and reptiles might “not age” at
all. However, recent studies on fish suggest that they age much as we do, only they big kinds do so more slowly. Tortoises
(land turtles) and sturgeon are probably the two longest-lived vertebrates (animals with backbones). Human beings are the
longest-lived mammals. The elephant is the other mammal that approaches our life span. In spite of what you read in many
books, whales and elephants do not live for hundreds of years.
THE DREAM OF LONGER LIFE

People have never liked to think that they would get old or that their lives would end around a fixed aged. So there have
always been stories about miraculous long lives and and about people that regained their young. A Greek myth tells us of
Eos (Aurora), goddess of the dawn, who prayed that her husband, Tithonus, be made inmortal. The prayed was granted,
but unfortunately she had forgotten to ask that he stay eternally young. So he grew older and older and more and more
decrepit until he prayed to be allowed to die.

Poets in the Middle Ages wrote of a Fountain of Youth in which one could bathe and become young. The fountain was a
fiction invented by the poets. But there was, at the same time, another group of people called alchemist. They were the
inventors of chemistry, though they mixed a great deal of magic in with it. The alchemists took over the dream of eternal
youth. They made it one of their three great projects: to change lead into gold, to travel to the moon, and to discover the
elixir of life, which would make old people young.

The alchemists failed to achieve these goals. Time passed and scientific knowledge grew. In the light of the new knowledge,
the three old dreams seemed seemed less and less likely ever to be realized. Scientists left them to lunatics and frauds. But
then more time passed, and the modern age of science arrived. In it the old dreams have started to come true.

Today we can change one metal into another in the atomic pile. Astronauts have visited the moon and returned safely. The
third of the alchemists” projects, the slowing down of aging, remains the hardest. It has not been achieved. It may be that
this is an impossible task, so that it will never be achieved. But many scientists, backed by a number of governments and by
various universities, are now planning and carrying out serious research on aging.

                                                       INVESTIGATIONS OF AGING

Work of aging is the new science of gerontology. (The name comes from the Greek geron, “an old man”) The aim of this
work is to collect as much knowledge as possible about aging in people and animals. The scientists who work in it want to
find out how and why aging happens. Eventually, if they can, they want to find out how to slow aging down and make people
stay healthy longer. We do not yet know why people and animals lose vigor with age. There seem to be three main
possibilities.

First, aging may be due to the dying-off of the cells we can not replace. The animals that do not age are mostly kinds that
can replace all their cells. In people and other vertebrates, cells of the skin, blood and liver are renewed. But this renewal
slows down with age. Other cells, like those of the brain, ca not divide and are never renewed. We keep the same brain cells
all our lives, but they get fewer as we get older. Aging may be due simply to a loss of cells or structures that we cannot
renew.

A second possibility has to do with cell formation. Aging may due due to a change in the cells that are newly produced
throughout life. Perhaps the new cells formed by an old man are different from, and not so good as, new cells in a baby.

The third possibility is that aging is more complicated than this. It may be the result of development. Chemical changes in
the body make us grow up. Perhaps these same chemical changes eventually damage the body in some way and make it
grow old.

Those are only three of the theories that have been suggested to explain aging. Nobody yet knows for certain which, if any
of them is right.

Two important facts have already been discovered, however. One concerns very small doses of doses of radiation (X rays
and the rays given off by radium, called gamma rays) given to mice. The doses shorten the lives of mice in a way that
strongly suggests they are hastening the normal aging process. This is very interesting. It does not mean that aging is due
wholly to the “background” radiation to which we are exposed all the time. But it may mean that the changes in aging animals
and the changes brought about by radiation are similar. If this is right, it will be a big step toward understanding aging. And it
raises another possibility. There are drugs that can protect us against radiation effects. Perhaps similar drugs could protect
us against aging.

The other discovery is that aging can be slowed down. It can be slowed by slowing growth and development. A great many
animals (cockroaches, for instance) have shorter lives if they are fed heavily and made to grow as fast as possible. They
live longer if they eat less and grow more slowly. Dr. Clive M. McCay, at Cornell University, found that this was also true of
rats. Other scientists have repeated his experiments. Litters of young rats are divided at random into two groups. One group
is fed a normal rat diet; the other gets everything it needs except enough energy-giving food (calories) to grow. The fully fed
group up, become adult, live their lives, and die of old age. During the same period of time, the underfed group stay
apparently young. And they can be made to grow long after their fully fed brothers and sisters are dead of old age. This
mean that aging can be made to “mark time”. Aging is nor simply a matter of passing weeks and months, but also of the rate
of living. McCay's experiment does not mean, of course, that starving people will live longer than the well fed. Starvation in
people is a shortage of everything . The rats were short only of enough energy foods for growth.

In McCay;s experiment both growth and development were affected. The rats stayed small and did not become able to
breed. Fish that are underfed stay small but become adult and able to breed.. However, they too live longer that fish that
grow fast It seems that slowing of growth slows down aging in a great many animals. Some body materials, such as the
collagen in the tendons, stay chemically “young” in the slowed-down animals.

Most research on slowing down aging is now concerned with the brain. Certain parts of the brain are known to act as the
“clocks” that control growing up and becoming adult. There is much evidence that while many “aging processes” are going
on in different part of the body, it is the brain- in a region called the hypothalamus- that controls and organizes life span.
The effects of changed diets on the life span are probably brought about by this controlling action of the brain.

One of the difficulties in trying to slow aging in people is the long wait involved. It would take a lifetime, 70 to 80 years, to
conduct experiments in aging. But researchers are studying certain factors that might be useful in measuring aging. Skin
elasticity and mental performance, for example, change with age. If reliable test of these and other factors can be worked
out, it will be possible to do experiments directly on people, aimed at prolonging their lives.

                                                      SHOULD PEOPLE LIVE LONGER?

Gerontologist are sometimes asked if they really think it is a good idea to make people live longer. Obviously it would raise
many population problems, but all big new discoveries give rise to problems, as the airplane and the nuclear energy have
done. Certainly if we only made people live longer, like Tithonus, it would not be a good thing. On the other hand, there are
some people of 80 who are ill or crippled because of age, while others are well and active. If we could all be well and useful
at 80, that would be a great improvement even if we lived no longer in the end. Now we spend nearly a third of our lives
learning our jobs. If we lived longer, we could do more work in a lifetime. We could carry out bigger and better plans.

The possibility of lengthening life raises some difficult questions, though we do not need to solve them yet. At the moment
we do not know for certain whether we can ever hope to change the rate of aging. Yet everyone should think about the
problems because scientists are making a serious attempt to find the means of slowing aging. It seems reasonable to think
they will succeed eventually -but when and by how much nobody can yet say.

Movie stars and the rich and famous have access to many cosmetic and other surgical options most of us do not. The Issue
with this is that it does not make them live longer, it just makes them die more "gracefully looking" than most of us.