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June 1998
PEP Pioneers
Second Wind
Torrance, California
Dear Friends:
Telomeres, are structures within the cells of all living plants
and animals that control the aging process. Telomeres are also
involved in cell alterations which result in cancer. The length
of life of our body's cells has something to do with how many
times the basic cells can divide and replace themselves. The number
of cell divisions has been believed to be controlled by a biological
clock, so that after so many divisions, let's say, around fifty,
cells die, even though they have the same nutrients. By contrast,
cancer cells never die. Thus, the price of cellular immortality
is malignancy. The problem in cancer is that normal cell death
and replacement does not occur. The concepts of senescence and
malignancy appear to be contradictory, since similar fundamental
biological processes control both. Can telomeres be both altered
so that sequence can be delayed, i.e., length of life extended,
and at the same time, cancer avoided? No one knows the answer
to this question, but the understanding of fundamental biological
processes now taking place in many laboratories suggests that
this may be the case.
The longest anyone has ever lived is 122 years. How anyone can
live this long has baffled scientists. Is length of life increasing?
In large populations, the answer is no. Careful data has been
kept in Scandinavian countries since the beginning of this century.
The same number of people, approximately one in 100,000, live
to be 100. But in this century, the average age of death has increased
about twenty years. So what we are doing in medicine, is preventing
premature morbidity and mortality, rather than extending the boundaries
of life.
Fundamental factors in the aging process is the creation of free
radicals, or oxidants, produced in the process of energy production
as food is oxidized. Energy is necessary for the sustenance of
life of cells and organs. Antioxidants, available through food
and vitamins, may postpone this process. The most important ways
to prevent premature aging of critical organs such as in emphysema
and atherosclerosis, is to stop smoking and to lower cholesterol.
Thus, we must also consider the interrelationship between environmental
and behavioral factors in the process of aging and death.
When I fish in the Northwest Territories for giant lake trout,
I marvel at the fact that each fish is two years old for each
pound weighed. So, a twenty-five pounder is fifty years old. Naturally,
I want to return these magnificent trout to the water. You can
tell the age of the trout by counting the growth rate on the scales,
just as one counts the rings of a tree. In this cold environment,
these fish do not grow for a large part of the season, in the
deep freeze of their environment. Growth is at the cost of free
radical production, which in turn relates to age. We humans, being
warm-bodied, do not enter a annual deep freeze. Thus, we must
begin to understand how we age via cruise control and what
we can do to extend the frontier of our lives. The genes that
control our cellular functions have been given us at the moment
of conception. How we can modify our allotted time is partly up
to us.
I will be
in touch next month.
Your friend,
Thomas Petty, MD
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