Sex Sleep Eat Drink Dream (30 page)

What may lie at the heart of all the body's clocks is an ingenious self-winding mechanism that enables a cell to tell time. A set of genes interact in tight negative-feedback loops to produce the oscillation, or tick-tock, in their own expression. Some of these genes make daylight proteins, which accumulate during the day. When they reach a peak level in the evening, they shut off the biochemical activity that leads to their own production. The result is a robust, self-sustaining loop that cycles continuously over twenty-four hours.

Imagine if we could feel the rotation of these intimate circles that drive our bodies. Perhaps this would temper our habit of ticking off digitized minutes and linear hours; perhaps it would restore our childlike experience of time as a revolving ring made of the smaller circumferences of a day. At the very least it might nurture more respect for our natural cyclical rhythms.

There's a thin sliver of moon in the sky. I lie for a moment in the dark and think about the body's little loops, its inner lark or owl and helpful microbial handmaidens, its exquisite senses and love of natural light, its need for sleep. Though we still know little about many aspects of bodily existence, the gaps in our knowledge are narrowing. The body is like an Antarctica, a continent being opened up, mapped, even transformed. With new understanding come new and useful tools for making the best of our own strange and temporary vessels.

With the first pale hints of light on the horizon, sleep finally takes possession, sweet and irresistible, subduing thoughts and senses. Whatever its purpose, thank goodness each day dies with it. There are some who would choose to run uninterrupted around the clock. But I can't imagine pressing on relentlessly through day and night with mind, body, spirit in a single state, can't imagine denying myself the possibility of a fresh start.

ACKNOWLEDGMENTS
NOTES INDEX

Acknowledgments

I WOULD LIKE TO THANK
three scientists who helped me in various ways and who have devoted their careers to the study of time in the body: Mike Menaker of the Center for Biological Timing at the University of Virginia, who read portions of the manuscript at various stages and offered helpful suggestions; William Hrushesky of the University of South Carolina, whose excellent 1994 article on timing in health and disease in
The Sciences
first introduced me to the topic of chronobiology, and who later suggested readings on chronotherapy; and Michael Smolensky of the University of Texas, whose book, written with Lynne Lamberg,
The Body Clock Guide to Better Health
(Henry Holt, 2000), was a welcome and authoritative guide to the role of the biological clock in health and daily life.

I cannot begin to adequately thank these scientists and the many others who helped me prepare this book. For their generous and kindly guidance, suggestions for additional reading, and corrections of my manuscript, I am especially indebted to Josephine Arendt of the University of Surrey; Paul Breslin of the Monell Chemical Senses Center; David E. Cummings of the University of Washington; William C. Dement of Stanford University School of Medicine, author, with Christopher Vaughan of the outstanding book
The Promise of Sleep
(Random House, 1999); A. Roger Ekirch of Virginia Tech, who offered not only helpful suggestions and encouragement but also inspiration in the form of his masterly work on night,
At Day's Close: Night in Times Past
(Norton, 2005); Helen Fisher of Rutgers University; Jeffrey Gordon of Washington University; Jay A. Gottfried of Northwestern University; Carla Green of the University of Virginia; Jack Gwaltney of the University of Virginia, who fielded my many questions about the common cold; H. Craig Heller of Stanford University; Richard Ivry of the University of California at Berkeley; Eric Kandel of Columbia University; Christof Koch of the California Institute of Technology; Art Kramer of the University of Illinois; Christopher Landrigan of the Harvard Work Hours, Health, and Safety Study at Harvard Medical School; Joseph LeDoux of New York University; Daniel E. Lieberman of Harvard University; Bruce McEwen of Rockefeller University, whose book
The End of Stress as We Know It
(Dana Press, 2002) was a superb tour of the subject; Janet Metcalfe of Columbia University; Thomas Reilly of Liverpool John Moores University; Craig Roberts of the University of Liverpool; Till Roenneberg of the Centre for Chronobiology at Ludwig-Maximilians-University in Munich; Mel Rosenberg of Tel Aviv University; Timothy Salthouse of the University of Virginia; Sally and Bennett Shaywitz of the Yale School of Medicine; Jerome Siegel of the University of California at Los Angeles; Ullrich Wagner of the University of Lübeck; and Charles Wysocki of the Monell Chemical Senses Center.

I am also deeply grateful to the following scientists, who read sections of the manuscript and offered useful comments: Paul Bach-y-Rita of the University of Wisconsin, James Blumenthal of Duke University, Jan Born of the University of Lübeck, Richard A. Bowen of Colorado State College, Arthur Burnett of Johns Hopkins School of Medicine, William Carlezon of Harvard University, Mary Carskadon of Brown University, Priscilla Clarkson of the University of Massachusetts, Richard Cytowič, Angelo Del Parigi of Pfizer Global R&D, Scott Diamond of the University of Pennsylvania, Brad Duchaine and Henrik Ehrsson of University College London, Jeffrey Flier of Harvard Medical School, Kevin Foster of Harvard University, Lynn Hasher of the University of Toronto, J. Owen Hendley of the University of Virginia, J. Allan Hobson of Harvard University, Gert Holstege of the University of Groningen, Jim Hudspeth of Rockefeller University, Laura Juliano of American University, Philip Kilner of the Imperial College of London, Kristen Knutson of the University of Chicago, Barry Komisaruk of Rutgers University, Peretz Lavie of Technion—Israel Institute of Technology, Peter Lucas of George Washington University, Sara Mednick of the Salk Institute for Biological Studies, David Meyer of the University of Michigan, Michael Miller of the University of Maryland Medical Center, Tore Nielsen of the University of Montreal, Tim Noakes of the University of Cape Town, Charles P. O'Brien of the University of Pennsylvania, Håkan Olausson of Sahl-grenska University Hospital, Steven Platek of the University of Liverpool, George Preti of the Monell Chemical Senses Center, Eric Ravussin of the Pennington Biomedical Research Center, Naftali Raz of Wayne State University, Allan Rechtshaffen, Marianne Regard of University Hospital Zurich, Michael Sayette of the University of Pittsburgh, Dee Silverthorn of the University of Texas, Dana Small of Yale University Medical School, Esther Sternberg of the National Institutes of Health, D. Michael Stoddart of the University of Tasmania, Henning Wackerhage of the University of Aberdeen, Peter Weyand of Rice University, Carol Worthman of Emory University, and Shawn Youngstedt of the Arnold School of Public Health at the University of South Carolina.

Errors may yet lurk in these pages, but it is thanks to those I've noted in the paragraphs above that there aren't many more.

In the course of the four years it took to write this book, I was fortunate enough to receive a fellowship in nonfiction from the National Endowment for the Arts. I could not have finished the book without this support. My appreciation goes to the late Cliff Becker for his interest in my project and, especially, for his passionate championing of literature.

For many different kinds of help, deep thanks to my close friend and collaborator Miriam Nelson, who offered in spades the kind of expertise, support, and enthusiasm treasured by her large circle of friends. I'm also very grateful to Francesca Conte, Harri Wasch, and Heather Sellers, who shared with me tales from their lives, and to my friend Dan O'Neill, who read an early draft of the manuscript and made many intelligent and helpful suggestions. Thanks also to my fine editors at the
Yale Alumni Magazine,
Kathrin Lassila and Bruce Fell-man, and at
National Geographic:
Lynn Addison, Oliver Payne, Jennifer Reek, and Caroline White.

I'm grateful to Laurence Cooper for his careful editing of the manuscript, to Will Vincent for his competent and cheerful help with the publishing process, and to Martha Kennedy for her inspired book title suggestion and jacket design. Special thanks to Janet Silver for her patience and generous support and to Melanie Jackson, always a font of wisdom and good judgment. To Amanda Cook I will say only this: You're the sort of editor every writer dreams of—smart, talented, articulate, and funny to boot. I can't thank you enough for your help in shaping, smoothing, and polishing this book.

Finally, my deepest gratitude goes to my dear girls, Zoë and Nell, and to my husband, Karl, for his love and for his willingness to take on, with characteristic courage and fortitude, the outside world while I was engrossed in the inside one.

Notes

page
PROLOGUE

[>]
 
we have learned that the human body:
P. B. Eckburg et al., "Diversity of the human intestinal microbial flora,"
Science
308, 1635–38 (2005).
"
timing is everything":
"Timing is everything,"
Nature
425, 885 (2003).
"
Nature is nowhere accustomed":
Thomas Willis quoted in Oliver Sacks, "To see and not see,"
The New Yorker,
May 10, 1993, 59.

[>]
 "
Our body is like a clock":
Robert Burton,
The Anatomy of Melancholy.
Available at
www.psyplexus.com/burton/7.htm
.

[>]
 "
I should not talk so much":
Henry David Thoreau,"Economy," in
Walden and Other Writings of Henry David Thoreau
(New York: Modern Library, 1992), 3.

1. AROUSAL

[>]
 
Some people claim that subtle aural trigger:
"Beating the bell,"
New Scientist,
letters by Jim Field and Radko Osredkar, May 14, 2005.
Scientists at Brown University documented:
M. A. Carskadon and R. S. Herz, "Minimal olfactory perception during sleep: why odor alarms will not work for humans,"
Sleep
27:3, 402–5 (2004).

[>]
 
When Peretz Lavie, a sleep researcher:
Peretz Lavie et al., "It's time, you must wake up now,"
Perceptual and Motor Skills
49, 447–50 (1979).
Another study showed:
Jan Born, "Timing the end of nocturnal sleep,"
Nature
397, 29–30 (1999).
In a nation that averages:
Till Roenneberg et al., "Life between clocks: daily temporal patterns of human chronotypes,"
Journal of Biological Rhythms
18:1, 80–90 (2003).
Unfortunately, the short bouts:
Edward Stepanski, Rush University Medical Center, Chicago, quoted in Martica Heaner, "Snooze alarm takes its toll on nation,"
New York Times,
October 12, 2004, D8.

[>]
 
If the snoring sinner ignored:
"An alarming bed,"
Scientific American,
October 1955, reprinted in
Scientific American,
October 2005, 16.
Only slightly more humane:
http://alumni.media.mit.edu/~nanda/projects/clocky.html.

[>]
 "
The brain just doesn't go from 0 to 60":
Quote and anecdote about the U.S. Air Force are from Charles Czeisler, "Sleep: what happens when doctors do without it," Medical Center Hour, University of Virginia School of Medicine, Charlottesville, March 1, 2006.
When a team of scientists:
K. W. Wright et al., "Effects of sleep inertia on cognition,"
Journal of the American Medical Association
295:2, 163 (2006).
Lavie's team found that people:
Lavie et al., "It's time, you must wake up now."

[>]
 
To eliminate such rude awakenings:
See the SleepSmart Web site:
www.axonlabs.com/pr_sleepsmart.html.
Whether you hop or drag:
Roenneberg et al., "Life between clocks."
Such is the pattern, too, for the great geneticist:
Jonathan Weiner,
Time, Love, Memory
(New York: Knopf, 1999), 190.
The "birds" differ dramatically:
Michael Smolensky and Lynne Lamberg,
The Body Clock Guide to Better Health
(New York: Holt, 2000), 40–42.
Till Roenneberg, a chronobiologist:
Roenneberg et al., "Life between clocks."

[>]
 
You can assessyour own
staf‹s:
www.imp-muenchen.de/mdex.php?id=932
.
Some time ago, a group of British researchers:
C. Gale, "Larks and owls and health, wealth, and wisdom—sleep patterns, health, and mortality,"
British Medical Journal,
December 19, 1998, E3 (col. 5).
Almost a decade ago, Hans Van Dongen:
H.P.A. Van Dongen, "Inter- and intra-individual differences in circadian phase," Ph.D. thesis, Leiden University, Netherlands, isbn 90-803851-2-3 (1998); H.P.A. Van Dongen and D. F. Dinges, "Circadian rhythms in fatigue, alertness, and performance," in M. H. Kryger et al.,
Principles and Practice of Sleep Medicine,
3rd ed. (Philadelphia: W. B. Saunders, 2000). See also J. F. Duffy et al., "Association of intrinsic circadian period with morningness-eveningness, usual wake time, and circadian phase,"
Behavioral Neuroscience
115:4, 895–99 (2001).
Although you might be able to overcome:
Hans Van Dongen Q & A at
www.upenn.edu/pennnews/current/2004/092304/cover.html
, retrieved March 17, 2005.
"
Time is the substance":
Jorge Luis Borges, "A New Refutation of Time,"
Labyrinths
(New York: Modern Library, 1983), 234.
To understand this, think back:
The following derives from Ezio Rosato and Charlambos P. Kyriacou, "Origins of circadian rhythmicity,"
Journal of Biological Rhythms
17:6, 506–11 (2002); Russell Foster and Leon Kreitzman,
Rhythms of Life
(London: Profile Books, 2004), 157 f.