Table Of ContentTIME
OF OUR
LIVES
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TIME
OF OUR
LIVES
The Science
of Human Aging
T O M K I R K W O O D
OXFORD
UNIVERSITY PRESS
OXFORD
UNIVERSITY PRESS
Oxford New York
Athens Auckland Bangkok Bogota Buenos Aires Calcutta
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and associated companies in
Berlin Ibadan
Copyright © 1999 by Tom Kirkwood
First published by Oxford University Press, Inc., 1999
First issued as an Oxford University Press paperback, 2000
198 Madison Avenue, New York, New York 10016
Oxford is a registered trademark of Oxford University Press
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted, in any form or by any means,
electronic, mechanical, photocopying, recording, or otherwise,
without the prior permission of Oxford University Press,
Library of Congress Cataloging-in-Publication Data
Kirkwood, Tom.
Time of our lives: the science of human aging / by Tom Kirkwood.
p. cm.
Includes bibliographical references and index.
ISBN 0-19-512824-9 (Cloth)
ISBN 0-19-513926-7 (Pbk.)
1.Aging—popular works. 1.Title.
QP86.K52 1999
612.6'7—dc21 98-46932
1 3 5 7 9 10 8 6 4 2
Printed in the United States of America
on acid-free paper
For my mother, Deborah Kirkwood, and
in memory of my father, Kenneth Kirkwood
Dangerous pavements.
But I face the ice this year
With my father's stick.
Seamus Heaney, '1.1.87'
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CONTENTS
Preface viii
1 The funeral season 1
2 Atitudes to ageing 12
3 What's in a name? 22
4 Longevity records 39
5 The unnecessary nature of
ageing 52
6 Why ageing occurs 63
7 Cels in crisis 81
8 Molecules and mistakes 100
9 Organs and orchestras 118
10 The cancer connection 147
11 Menopause and the big bang 161
12 Eat less, live longer 174
13 Why do women live longer
than men? 184
14 The Genie of the Genome 196
15 In search of Wonka-Vite 212
16 Making more time 230
Epilogue 243
Notes 257
Bibliography 261
Index 269
Preface
Today's older people are the vanguard of an extraordinary revolu-
tion in longevity that is radically changing the structure of society
and altering our perceptions of life and death. Improvements in
sanitation, housing, healthcare and education have resulted in huge
increases in expectation of life. Countless lives are now lived to the
full that might otherwise have been cut short. The price for this
success - and make no mistake, it is a success - is that we now face
the challenge of ageing.
Time of Our Lives is about the science of human ageing - one of
the last great mysteries of the living world. Questions like 'Why do
we age?', 'How does ageing happen?', 'Why do some species live
longer than others?', 'Why do women live longer than men?', 'Do
some parts of the body wear out sooner than others?' and 'Why do
women have a menopause halfway through their life span?' beg for
answers. The more practical question 'Can science slow my ageing
process, or help me age better?' concerns us all.
For all of these reasons, human ageing is at the forefront of
scientific, medical and social research and of political thinking as
never before. If we are to meet and overcome the immense
challenges of adjusting to the worldwide demographic revolution,
with all that this means in terms of longevity, economics and, above
all, quality of life, we need to be armed with better knowledge.
Time of Our Lives is written to be intelligible to a reader who has
no training in science, but an interest to know. It is also written for
those whose daily work brings them increasingly into contact with
PREFACE IX
older people. It even, I hope, has messages for the policy-makers,
those we elect to lead us into the uncharted territories of a greying
world.
It is not a textbook and yet it goes to the heart of current
research. Although I have been at pains to make every part of the
book informative and intelligible to the lay reader, I have avoided
oversimplication so that the real issues can be understood. I make
no excuse for asking the reader to work a little harder in some
chapters than others to follow material that may be unfamiliar. My
side of the bargain is that I have also worked hard to make the
science as accessible as possible, using everyday examples to help.
The focus is on ageing, of course, but quite a lot of other interesting
science has been included to set the stage. In writing for a diverse
readership, there is an unavoidable danger that one will sometimes
explain a point at greater length, or at a simpler level, than the
reader requires. Where I have failed to get the balance right, I hope
that this will not distract too much.
Many colleagues have helped my research over the years.
Particular thanks are due to Steven Austad, Thomas Cremer, loan
Davies, John Grimley Evans, Caleb Finch, Claudio Franceschi,
Leonard Hayflick, Robin Holliday, Tom Johnson, Axel Kowald,
Gordon Lithgow, George M. Martin, Ed Masoro, John Maynard
Smith, Leslie Orgel, Linda Partridge, Olivia Pereira Smith, Chris
Potten, Patrick Rabbitt, Francois Schachter, Daryl Shanley, Jim
Smith, Richard Sprott, Raymond Tallis, Roger Thatcher, James
Vaupel and Rudi Westendorp. I would also like to express my
appreciation to the organisations that have supported my research
at various times, particularly the UK Medical Research Council,
Research into Ageing, the Wellcome Trust, the Dunhill Medical
Trust and the UK National Biological Standards Board.
My agent, Felicity Bryan, first suggested that I write this book
and has nudged me gently but firmly towards its completion, an
event that I am sure she must at times have begun to doubt. My
visit to Navrongo, described in Chapter I, was made possible
through the work of Betty Kirkwood, and I am grateful to the many
