The Quest for Immortality: Science at the Frontiers of Aging
By S. Jay Olshansky and Bruce A. Carnes. 243 pp. New York, W.W. Norton,
2001. $25.95. ISBN 0-393-04836-5
http://www.nejm.org/content/2001/0344/0012/0941.asp
--------------------------------------------------------------------------
------
In 1990, biodemographers Olshansky, Carnes, and Cassel published a review
in Science entitled "In Search of Methuselah: Estimating the Upper Limits
to Human Longevity" (250:634-640). In the article they argued that,
despite the astounding increase in life expectancy during the 20th century
(increasing, in the United States, from a mean age of 45 at the beginning
of the century to 78 at its end), it was doubtful that we would witness an
increase in longevity to ages older than 85 during the foreseeable future.
This, they argued, reflected "entropy in the life table": it would be far
more difficult to increase life expectancy by curing illnesses in elderly
persons than it had been to nudge life expectancy upward by reducing
infant mortality. Any increase above the age of 85, they insisted, would
require biomedical breakthroughs in our ability to affect the basic
processes of aging itself and not just in our ability to treat diseases.
Their pessimism, while controversial, provided a much-needed shot of
realism in a field in which some researchers were seriously predicting
that life expectancy would soon rise above 100.
In The Quest for Immortality, Olshansky and Carnes present their work for
the general public and discuss life expectancy, the causes of aging, and
the efforts (both legitimate scientific research and bogus claims for
alternative therapies) to prolong life and delay aging. The book is well
written and is pleasant to read, with a folksy and unpretentious style.
For instance, as case histories of how medical interventions have delayed
untimely deaths and produced what the authors call "manufactured survival
time," they turn to Carnes's own father's bypass surgery and the removal
of Olshansky's own pilonidal cyst.
For readers interested in aging and longevity, this small book clearly
explains the major concepts in the field. Olshansky and Carnes show how
natural selection promotes health during the reproductive period but
contributes little benefit over the age of 60. They point out that it is
only in the past 100 years that most humans have begun to outlive their
reproductive years; diseases of aging are a recent development. Our
genetic heritage, they explain, has left us with bodies like cars that
were designed to perform flawlessly in the Indy 500 but whose drivers
insist on continuing many miles beyond the end of the race, until parts
inevitably start to fail. Aging is not a disease that can be cured. The
authors describe the free-radical theory of aging and the possibility that
genetic manipulation and antioxidants may affect the aging process and, at
the same time, decry the often outrageous claims currently made for
antioxidants. They review ancient myths of longevity and discuss diets and
dietary supplements aimed at averting aging. They point out that
proponents of such treatments, in fact, have died at the expected age and
of the usual causes.
Olshansky and Carnes also discuss possible scientific approaches,
primarily genetic manipulation, that might affect human aging, and they
lay out common-sense recommendations for a healthy life while revealing
the illogic of claims made by proponents of antiaging treatments. Though
targeted for the lay audience, this book will provide a useful
introduction for physicians and prepare them to answer their patients'
questions about longevity. The authors have an enviable ability to phrase
technical issues and arguments in clear, nontechnical language.
Though extremely enjoyable to read, this book has one important flaw that
will detract from its usefulness for physicians: a lack of references. The
decision to forgo references, suggestions for further reading, and
footnotes is unfortunate. The lack of references will largely restrict the
audience for this book to the general public and prevent it from being
used as a classroom aid for interested medical students and residents.
Howard Chertkow, M.D.
McGill University
Montreal, QC H3T 1E2, Canada
http://www.brogdon.org/ayb.swf
This archive was generated by hypermail 2b30 : Mon May 28 2001 - 09:59:42 MDT