PUBLIC POLICY AND SOCIETAL CHANGE
At the highest levels, we need better public campaigns educating the population about sleep. We spend a tiny fraction of our transportation safety budget warning people of the dangers of drowsy driving compared with the countless campaigns and awareness efforts regarding accidents linked to drugs or alcohol. This despite the fact that drowsy driving is responsible for more accidents than either of these two issues—and is more deadly. Governments could save hundreds of thousands of lives each year if they mobilized such a campaign. It would easily pay for itself, based on the cost savings to the health-care and emergency services bills that drowsy-driving accidents impose. It would of course help lower health-care and auto insurance rates and premiums for individuals.
Prosecutorial law regarding drowsy driving is another opportunity. Some states have a vehicular manslaughter charge associated with sleep deprivation, which is of course far harder to prove than blood alcohol level. Having worked with several large automakers, I can report that soon we will have smart technology inside of cars that may help us know, from a driver’s reactions, eyes, driving behavior, and the nature of the crash, what the prototypical “signature” is of a clearly drowsy-driving accident. Combined with a personal history, especially as personal sleep-tracking devices become more popular, we may be very close to developing the equivalent of a Breathalyzer for sleep deprivation.
I know that may sound unwelcome to some of you. But it would not if you had lost a loved one to a fatigue-related accident. Fortunately, the rise of semiautonomous-driving features in cars can help us avoid this issue. Cars can use these very same signatures of fatigue to heighten their watch and, when needed, take greater self-control of the vehicle from the driver.
At the very highest levels, transforming entire societies will be neither trivial nor easy. Yet we can borrow proven methods from other areas of health to shift society’s sleep for the better. I offer just one example. In the United States, many health insurance companies provide a financial credit to their members for joining a gym. Considering the health benefits of increased sleep amount, why don’t we institute a similar incentive for racking up more consistent and plentiful slumber? Health insurance companies could approve valid commercial sleep-tracking devices that individuals commonly own. You, the individual, could then upload your sleep credit score to your health-care provider profile. Based on a tiered, pro-rata system, with reasonable threshold expectations for different age groups, you would be awarded a lower insurance rate with increasing sleep credit on a month-to-month basis. Like exercise, this in turn will help improve societal health en masse and lower the cost of health-care utilization, allowing people to have longer and healthier lives.
Even with lower insurance paid by the individual, health insurance companies would still gain, as it would significantly decrease the cost burden of their insured individuals, allowing for greater profit margins. Everyone wins. Of course, just like a gym membership, some people will start off adhering to the regime but then stop, and some may look for ways to bend or play the system regarding accurate sleep assessment. However, even if only 50 to 60 percent of individuals truly increase their sleep amount, it could save tens or hundreds of millions of dollars in terms of health costs—not to mention hundreds of thousands of lives.
This tour of ideas offers, I hope, some message of optimism rather than the tabloid-like doom with which we are so often assaulted in the media regarding all things health. More than hope, however, I wish for it to spark better sleep solutions of your own; ideas that some of you may translate into a non- or for-profit commercial venture, perhaps.
Conclusion
To Sleep or Not to Sleep
Within the space of a mere hundred years, human beings have abandoned their biologically mandated need for adequate sleep—one that evolution spent 3,400,000 years perfecting in service of life-support functions. As a result, the decimation of sleep throughout industrialized nations is having a catastrophic impact on our health, our life expectancy, our safety, our productivity, and the education of our children.
This silent sleep loss epidemic is the greatest public health challenge we face in the twenty-first century in developed nations. If we wish to avoid the suffocating noose of sleep neglect, the premature death it inflicts, and the sickening health it invites, a radical shift in our personal, cultural, professional, and societal appreciation of sleep must occur.
I believe it is time for us to reclaim our right to a full night of sleep, without embarrassment or the damaging stigma of laziness. In doing so, we can be reunited with that most powerful elixir of wellness and vitality, dispensed through every conceivable biological pathway. Then we may remember what it feels like to be truly awake during the day, infused with the very deepest plenitude of being.
Appendix
Twelve Tips for Healthy Sleepfn1
1. Stick to a sleep schedule. Go to bed and wake up at the same time each day. As creatures of habit, people have a hard time adjusting to changes in sleep patterns. Sleeping later on weekends won’t fully make up for a lack of sleep during the week and will make it harder to wake up early on Monday morning. Set an alarm for bedtime. Often we set an alarm for when it’s time to wake up but fail to do so for when it’s time to go to sleep. If there is only one piece of advice you remember and take from these twelve tips, this should be it.
2. Exercise is great, but not too late in the day. Try to exercise at least thirty minutes on most days but not later than two to three hours before your bedtime.
3. Avoid caffeine and nicotine. Coffee, colas, certain teas, and chocolate contain the stimulant caffeine, and its effects can take as long as eight hours to wear off fully. Therefore, a cup of coffee in the late afternoon can make it hard for you to fall asleep at night. Nicotine is also a stimulant, often causing smokers to sleep only very lightly. In addition, smokers often wake up too early in the morning because of nicotine withdrawal.
4. Avoid alcoholic drinks before bed. Having a nightcap or alcoholic beverage before sleep may help you relax, but heavy use robs you of REM sleep, keeping you in the lighter stages of sleep. Heavy alcohol ingestion also may contribute to impairment in breathing at night. You also tend to wake up in the middle of the night when the effects of the alcohol have worn off.
5. Avoid large meals and beverages late at night. A light snack is okay, but a large meal can cause indigestion, which interferes with sleep. Drinking too many fluids at night can cause frequent awakenings to urinate.
6. If possible, avoid medicines that delay or disrupt your sleep. Some commonly prescribed heart, blood pressure, or asthma medications, as well as some over-the-counter and herbal remedies for coughs, colds, or allergies, can disrupt sleep patterns. If you have trouble sleeping, talk to your health care provider or pharmacist to see whether any drugs you’re taking might be contributing to your insomnia and ask whether they can be taken at other times during the day or early in the evening.
7. Don’t take naps after 3 p.m. Naps can help make up for lost sleep, but late afternoon naps can make it harder to fall asleep at night.
8. Relax before bed. Don’t overschedule your day so that no time is left for unwinding. A relaxing activity, such as reading or listening to music, should be part of your bedtime ritual.
9. Take a hot bath before bed. The drop in body temperature after getting out of the bath may help you feel sleepy, and the bath can help you relax and slow down so you’re more ready to sleep.
10. Dark bedroom, cool bedroom, gadget-free bedroom. Get rid of anything in your bedroom that might distract you from sleep, such as noises, bright lights, an uncomfortable bed, or warm temperatures. You sleep better if the temperature in the room is kept on the cool side. A TV, cell phone, or computer in the bedroom can be a distraction and deprive you of needed sleep. Having a comfortable mattress and pillow can help promote a good night’s sleep. Individuals who have insomnia often watch the clock. Turn the clock’s face out of view so you don�
��t worry about the time while trying to fall asleep.
11. Have the right sunlight exposure. Daylight is key to regulating daily sleep patterns. Try to get outside in natural sunlight for at least thirty minutes each day. If possible, wake up with the sun or use very bright lights in the morning. Sleep experts recommend that, if you have problems falling asleep, you should get an hour of exposure to morning sunlight and turn down the lights before bedtime.
12. Don’t lie in bed awake. If you find yourself still awake after staying in bed for more than twenty minutes or if you are starting to feel anxious or worried, get up and do some relaxing activity until you feel sleepy. The anxiety of not being able to sleep can make it harder to fall asleep.
Illustration Permissions
Figures were provided courtesy of the author except for the following.
Fig. 3. Modified from Noever, R., J. Cronise, and R. A. Relwani. 1995. Using spider-web patterns to determine toxicity. NASA Tech Briefs 19(4):82.
Fig. 9. Modified from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2767184/figure/F1/.
Fig. 10. Modified from http://journals.lww.com/pedorthopaedics/Abstract/2014/03000/Chronic_Lack_of_Sleep_is_Associated_With_Increased.1.aspx.
Fig. 11. Modified from http://www.cbssports.com/nba/news/in-multi-billion-dollar-business-of-nba-sleep-is-the-biggest-debt/. Source: https://jawbone.com/blog/mvp-andre-iguodala-improved-game/.
Fig. 12. Modified from https://www.aaafoundation.org/sites/default/files/AcuteSleepDeprivationCrashRisk.pdf.
Fig. 15. Modified from http://bmjopen.bmj.com/content/2/1/e000850.full.
Fig. 16. Modified from http://www.rand.org/content/dam/rand/pubs/research_reports/RR1700/RR1791/RAND_RR1791.pdf.
Acknowledgments
The staggering devotion of my fellow sleep scientists in the field, and that of the students in my own laboratory, made this book possible. Without their heroic research efforts, it would have been a very thin, uninformative text. Yet scientists and young researchers are only half of the facilitating equation when it comes to discovery. The invaluable and willing participation of research subjects and patients allows fundamental scientific breakthroughs to be uncovered. I offer my deepest gratitude to all of these individuals. Thank you.
Three other entities were instrumental in bringing this book to life. First, my inimitable publisher, Scribner, who believed in this book and its lofty mission to change society. Second, my deftly skilled, inspiring, and deeply committed editors, Shannon Welch and Kathryn Belden. Third, my spectacular agent, sage writing mentor, and ever-present literary guiding light, Tina Bennett. My only hope is that this book represents a worthy match for all you have given to me, and it.
THE BEGINNING
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PENGUIN BOOKS
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Penguin Books is part of the Penguin Random House group of companies whose addresses can be found at global.penguinrandomhouse.com.
First published in the United States of America by Scribner, an imprint of Simon & Schuster, Inc. 2017
First published in Great Britain by Allen Lane 2017
Published in Penguin Books 2018
Text copyright © Matthew Walker, 2017
Illustration credits appear here
The moral right of the author has been asserted
Cover photograph: Alkestida/Shutterstock
ISBN: 978-0-141-98377-6
CHAPTER 1 TO SLEEP …
fn1 The World Health Organization and the National Sleep Foundation both stipulate an average of eight hours of sleep per night for adults.
fn2 Sleepless in America, National Geographic, http://channel.nationalgeographic.com/sleepless-in-america/episode/sleepless-in-america.
fn3 Dr. Allan Rechtschaffen.
fn4 Kushida, C. Encyclopedia of Sleep, Volume 1 (Elsever, 2013).
CHAPTER 2 CAFFEINE, JET LAG, AND MELATONIN: LOSING AND GAINING CONTROL OF YOUR SLEEP RHYTHM
fn1 I should note, from personal experience, that this is a winning fact to dispense at dinner parties, family gatherings, or other such social occasions. It will almost guarantee nobody will approach or speak to you again for the rest of the evening, and you’ll also never be invited back.
fn2 The word pudica is from the Latin meaning “shy” or “bashful,” since the leaves will also collapse down if you touch or stroke them.
fn3 This phenomenon of an imprecise internal biological clock has now been consistently observed in many different species. However, it is not consistently long in all species, as it is in humans. For some, the endogenous circadian rhythm runs short, being less than twenty-four hours when placed in total darkness, such as hamsters or squirrels. For others, such as humans, it is longer than twenty-four hours.
fn4 Even sunlight coming through thick cloud on a rainy day is powerful enough to help reset our biological clocks.
fn5 For nocturnal species like bats, crickets, fireflies, or foxes, this call happens in the morning.
fn6 L. A. Erland and P. K. Saxena, “Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content,” Journal of Clinical Sleep Medicine 2017;13(2):275–81.
fn7 Assuming you have a stable circadian rhythm, and have not recently experienced jet travel through numerous time zones, in which case you can still have difficulty falling asleep even if you have been awake for sixteen hours.
fn8 There are other factors that contribute to caffeine sensitivity, such as age, other medications currently being taken, and the quantity and quality of prior sleep. A. Yang, A. A. Palmer, and H. de Wit, “Genetics of caffeine consumption and responses to caffeine,” Psychopharmacology 311, no. 3 (2010): 245–57, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4242593/.
fn9 The principal liver enzyme that metabolizes caffeine is called cytochrome P450 1A2.
fn10 R. Noever, J. Cronise, and R. A. Relwani, “Using spider-web patterns to determine toxicity,” NASA Tech Briefs 19, no. 4 (1995): 82; and Peter N. Witt and Jerome S. Rovner, Spider Communication: Mechanisms and Ecological Significance (Princeton University Press, 1982).
fn11 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3902880/bin/aasm.37.1.9s1.tif (source: D. J. Buysse, “Sleep Health: Can we define it? Does it matter?” SLEEP 37, no. 1 [2014]: 9–17).
CHAPTER 3 DEFINING AND GENERATING SLEEP: TIME DILATION AND WHAT WE LEARNED FROM A BABY IN 1952
fn1 Some people with a certain type of insomnia are not able to accurately gauge whether they have been asleep or awake at night. As a consequence of this “sleep misperception,” they underestimate how much slumber they have successfully obtained—a condition that we will return to later in the book.
fn2 Different species have different NREM–REM cycle lengths. Most are shorter than that of humans. The functional purpose of the cycle length is another mystery of sleep. To date, the best predictor of NREM–REM sleep cycle length is the width of the brain stem, with those species possessing wider brain stems having longer cycle lengths.
fn3 Oddly, during the transition from being awake into light stage 1 NREM sleep, the eyes will gently and very, very slowly start to roll in their sockets in synchrony, like two ocular ballerinas pirouetting in perfect time with each other. It is a hallmark indication that the onset of sleep is inevitable. If you have a bed partner, try observing their eyelids the next time they are drifting off to sleep. You will see the closed lids of the eyes deforming as the eyeballs roll around underneath. Parenthetically, should you
choose to complete this suggested observational experiment, be aware of the potential ramifications. There is perhaps little else more disquieting than aborting one’s transition into sleep, opening your eyes, and finding your partner’s face looming over yours, gaze affixed.
CHAPTER 4 APE BEDS, DINOSAURS, AND NAPPING WITH HALF A BRAIN: WHO SLEEPS, HOW DO WE SLEEP, AND HOW MUCH?
fn1 Proof of sleep in very small species, such as insects, in which recordings of electrical activity from the brain are impossible, is confirmed using the same set of behavioral features described in chapter 3, illustrated by the example of Jessica: immobility, reduced responsiveness to the outside world, easily reversible. A further criterion is that depriving the organism of what looks like sleep should result in an increased drive for more of it when you stop the annoying deprivation assault, reflecting “sleep rebound.”
fn2 It was once thought that sharks did not sleep, in part because they never closed their eyes. Indeed, they do have clear active and passive phases that resemble wake and sleep. We now know that the reason they never close their eyes is because they have no eyelids.
fn3 A. Roger Ekirch, At Day’s Close: Night in Times Past (New York: W. W. Norton, 2006).
CHAPTER 5 CHANGES IN SLEEP ACROSS THE LIFE SPAN
fn1 The exception, noted in chapter 4, may be newborn killer whales. They do not appear to have the chance for sleep right after birth, as they have to make the perilous journey back to their pod from the calving fields miles away, shadowed by their mother. However, this is an assumption. It remains possible that they, like all other mammals, still consume in utero large volumes of sleep, and even REM sleep, just prior to birth. We simply do not yet know.
Why We Sleep Page 38