Book Notes: Why We Sleep

Summary

The book explains what is sleep, what it isn’t, how human beings should sleep and how sleep changes across your life span from a scientific point of view. It also details the good, the bad, and the deathly of sleep and sleep loss. It explores all the benefits of sleep for brain and for body health and wellness. It also talks about the science about dreams. It explains numerous sleep disorders, including insomnia. It provides useful tips for having better sleep.

Notes

I always knew the importance of a good night of sleep in my daily life, even though I didn’t know in what specific ways sleep affected me.

When I was younger, I always worked or studied up until late at night and woke up early feeling awful, but I thought that it was the way it was supposed to be.

That mentality hasn’t changed as I grew older. Everywhere I looked, my coworkers, most of my friends, my family, they all believed that sleeping a lot was lazy, so having 8 hours of sleep every night was luxurious. In my family we used to say that those 8 hours of sleep were the “beauty’s sleep”. I must say that, being struggling all my life to have a place in a male-dominated world, I hated that expression with all my heart.

Do we really need seven or eight hours of sleep every night? According to the research presented by Dr. Walker, yes. Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer. Sleep disruption further contributes to all major psychiatric conditions, including depression, anxiety, and suicidality. The ultimate conclusion: the shorter your sleep, the shorter your life span. Ouch!

I also grew up believing that I was immune to caffeine, that it didn’t affect my sleep (ha-ha-ha). I have been a coffee drinker since my teens, influenced by my parents. They loved coffee so much, especially my mom. We all love strong coffee. My parents and I used to drink coffee, the Brazilian style (dripped coffee in small espresso cups) several times a day: at breakfast, mid-morning, after lunch, mid afternoon, some times at dinner or after dinner. Today, as I write this, I cringe just to remember those days. I should have known better.

Then I started to notice that my sleep was usually fragmented. I woke up many times every night. But I always thought it was because I had a light sleep. The mistaken belief of being immune to caffeine was also made stronger because I didn’t have difficulty to fall asleep, except for when I was worried about something. More recently, about a year ago, I started noticing that caffeine was affecting my sleep. I was taking longer to fall asleep when I drank coffee late in the afternoon. So, as an experiment, I started avoiding coffee after 3 p.m. It worked in part, but I still had a fragmented sleep.

After reading Why We Sleep, a lot of things started to make sense. Caffeine was only one variable in the equation. I was shocked to know that caffeine has an average half-life of five to seven hours. In pharmacology, the term “half-life” refers to the length of time it takes for the body to remove 50 percent of a drug’s concentration. This means that if you have a cup of coffee after your evening dinner, around 7:30 p.m., by 1:30 a.m., 50% of that caffeine may still be active and circulating throughout your brain tissue. I was also not aware that caffeine is the most widely used (and abused) psychoactive stimulant in the world. Even NASA in the 1980s conducted research to determine drugs’ toxicity using spider-web patterns. Those drugs included LSD, speed (amphetamine), marijuana, and caffeine. The results can be observed below.

Aging also alters the speed of caffeine clearance: the older we are, the longer it takes our brain and body to remove caffeine, and thus the more sensitive we become in later life to caffeine’s sleep-disrupting influence. That explains why I started noticing being affected by caffeine.

I was also shocked to know that alcohol also affects sleep in a bad way. I love having a glass of wine at dinner. It makes me feel relaxed and ready to end my day. Many individuals believe alcohol helps them to fall asleep more easily, or even offers sounder sleep throughout the night. According to Dr. Walker, both are resolutely untrue. Alcohol is in a class of drugs called sedatives and sedation is not natural sleep. Alcohol is like a light form of anesthesia and impairs an individual’s sleep in two other ways: it fragments sleep and it suppresses REM sleep. REM sleep aids in memory integration and association and fuels creativity and problem-solving abilities. I can’t yet make myself avoid that glass of wine every evening, but I started decreasing the quantity and having it earlier in the evening.

There are other factors that influence the quality of our sleep. At the end of the book, Dr. Walker provides twelve tips for having better sleep. In summary, they are:

1. Stick to a sleep schedule. Go to bed and wake up at the same time each day, including weekends. 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. This is the most important tip he thinks we should follow.
2. Exercise frequently. 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.
4. Avoid alcoholic drinks before bed.
5. Avoid large meals and beverages late at night.
6. If possible, avoid medicines that delay or disrupt your sleep.
7. Don’t take naps after 3 p.m.
8. Relax before bed. Keep enough time in your schedule for unwinding. It is good to have a bedtime ritual.
9. Take a hot bath before bed.
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.

You can buy the English edition e-book here (affiliated link).

Você pode comprar a edição em Português do e-book aqui (link associado).