Description

* 200,000 copies sold in the UK * Published in 35 countries worldwide * Amazon UK and US bestseller * New York Times bestseller * Sunday Times bestseller (49 consecutive weeks) * Selected as 2017 Book of the Year by The Guardian, The Observer, Financial Times, Daily Mail, Evening Standard, Publishers Weekly, and NPR Matthew Walker, a world-renowned neuroscientist and sleep expert, presents "Why We Sleep" published by 열린책들. Walker is a leading scholar in the field of sleep medicine, having published over 100 scientific papers, and is recognized as a self-proclaimed "sleep diplomat" who actively engages with the public through television and radio. In this book, the author explains the various aspects of sleep that we were previously unaware of, backed by scientific evidence, and offers profound insights on how to leverage the remarkable powers of sleep to improve our lives. The Science of Sleep and Dreams Humans spend two-thirds of their lives awake. We move around with consciousness, spending what is called productive time. We engage in social activities, protect ourselves from threats to survival, obtain food, and reproduce. In contrast, the remaining time when we cannot perform these actions—i.e., when we are sleeping—seems evolutionarily very unproductive. Yet, we still sleep. The fact that all living beings sleep despite obvious dangers clearly indicates that there are immense benefits that outweigh the risks. At the very least, numerous studies consistently show that sleeping well does not exclude us from biological benefits. In fact, there is no reason for us not to sleep. Unfortunately, humans are the only species that intentionally reduce their sleep time. The author's argument is clear: we should focus on making the most of one-third of our lives. Sleep is the most important yet least understood activity concerning our lives, health, and longevity. Until very recently, science could not answer questions such as why we sleep, how sleep helps our bodies and brains, and why lack of sleep leads to serious health issues. Compared to other basic needs like hunger, thirst, and sexual desire, sleep has been a significantly less understood topic relative to its quantitative and qualitative importance in human life. Over the past 20 years, scientific discoveries have exploded, and the topic of sleep has begun to be redefined. What do we gain from sleep? The benefits of sleep mentioned by the author in this book are truly astonishing. By getting enough sleep, we can enhance our memory and creativity. Those who sleep well appear more attractive than those who do not. Sleep helps maintain a slimmer physique and reduces appetite. It prevents cancer and dementia and protects against colds and flu. The risks of heart attacks, strokes, and diabetes decrease. Our mood improves, and feelings of depression and anxiety diminish. Dreams that accompany sleep alleviate painful memories from our waking hours. The brain creates a virtual reality that allows it to merge past and present knowledge, fostering creativity. Sleep and dreams perform countless functions in our bodies and minds. For Those Who Have Forgotten the Night How many hours of sleep are appropriate for a person? Five hours? Six hours? Seven hours? Consider the morning scene of modern individuals. Every morning, they wake up with the help of an alarm clock and consume caffeine to maintain a clear mind. This seemingly ordinary behavior is actually a prime example of the sleep deprivation phenomenon observed worldwide, and the World Health Organization has already declared sleep deprivation an epidemic across developed countries. The United States, the UK, South Korea, and Japan are among the countries that have seen the most significant reductions in sleep time over the past century, and they are also the countries where the number of patients suffering from diseases and mental disorders caused by lack of sleep has increased the most. We somehow wake up from sleep and start our day. However, it is difficult to shake off the feeling of sleep deprivation throughout the day. If one wonders whether it is necessary to use the term epidemic for slight sleep deprivation, let’s take a look at the following symptoms that occur in our bodies when we lack sleep. Insufficient sleep first damages our immune system. The risk of cancer doubles, and changes that can be considered precursors to Alzheimer’s disease and diabetes occur in the body. Cardiovascular diseases, strokes, and congestive heart failure occur. Lack of sleep exacerbates symptoms of major mental disorders, including depression, anxiety, and suicide. Furthermore, shorter sleep duration leads to a shorter lifespan. This is why the author describes sleep deprivation as "a slow form of self-euthanasia." Fortunately, the numerous scientific data and analyses in this book prescribe a remedy that can solve all these issues at once. A cost-free natural remedy—getting more than eight hours of sleep—is exactly that. For Those Battling Drowsiness Despite the clear benefits of sleep, we work hard to reduce it. The rationalizations we make to cut down on sleep are endless, such as being a morning person, escaping the stigma of laziness and lack of willpower, and the basic qualities of being a modern individual. Of course, there are people who are naturally short sleepers. They wake up without the help of an alarm clock after only six hours of sleep and do not need to sleep again until the end of the day. These individuals are unaffected by sleep due to specific genetic influences. People may believe they belong to this category. Their daily lives may indeed reflect a pattern of sleeping less and staying awake longer, but the likelihood of actually being in such a category is extremely rare. The author explains this by quoting a colleague: "If we express the number of people who can live without any issues on five hours of sleep or less as a population percentage, it rounds to zero." Can we really think we belong to a group that is less than one percent of the population, a probability lower than being struck by lightning? Sleep is the most effective and only means to renew our brain and body health every day. Yet, individuals and society today rarely mention sleep in discussions about health. Executives or employees who work early in the morning until late at night do not contribute to their companies; instead, they make poor decisions due to lack of sleep, causing significant losses. Residents working 30-hour shifts make incorrect diagnoses and commit mistakes like leaving surgical instruments inside patients. Drowsy driving causes more accidents than drunk driving, yet the efforts to prevent it are less than two percent compared to those for drunk driving. We must sleep. Almost every question the author poses in this book perfectly explains why we need to sleep. How do caffeine and alcohol affect sleep? What actually happens during REM sleep? Why do our sleep patterns change as we age? How do commonly encountered sleeping pills work, and what long-term harm can they cause us? How do dreams enhance learning, mood, vitality, and regulate hormones? What is the relationship between sleep and children's growth, workplace efficiency, achievement, and productivity? Written clearly, engagingly, and understandably, this book will completely transform the reader's understanding and perception of sleep. Let’s make the most of one-third of our day. That is the most efficient and perfect way to utilize the remaining two-thirds of our lives.