Image Description: a yellow alarm clock showing the time as quarter to five, on white bedding
This article is based on the book ‘Why We Sleep: The New Science of Sleep and Dream,’ by Matthew Walker.
Did you get enough sleep this past week? Can you remember the last time you woke up feeling refreshed and well-rested, without needing caffeine to get you through the day? No? Me neither.
Most people in developed nations feel this way. Failing to obtain the recommended eight hours of sleep per night has become so common in society that we barely stop to think about its consequences. Sleep is often seen as a nuisance, a waste of time standing in the way of our productivity, our hobbies, and our social lives. As a result, it is often the first aspect we’re willing to compromise in order to devote sufficient time to other more important activities. But are these other activities really more important than sleep? Research from the last decade years suggests that they aren’t. In fact, it is becoming clear that there may be no part of your day more important than sleep. Regularly sleeping less than seven hours a night wreaks havoc on your body, increasing your risk of cancer, cardiovascular disease and Alzheimer’s disease, and drastically reducing the power of your immune system to ward off infections. It may not be a coincidence that countries in which sleep times have decreased most dramatically over the past decades, including the UK, are also facing the largest rise in rates of these diseases.
Hearing this for the first time, I was stunned. Why hadn’t I heard more about how important sleep is to our health? Most of us know about the importance of diet and exercise, and make at least some effort to occasionally eat a vegetable and get our heart rate up. But the fact that sleep is a third factor of vital importance to our health doesn’t seem to have reached public awareness. Perhaps this is due to society’s generally negative attitude towards sleep. We tend to glorify high-powered individuals who answer emails at 1am and are back in the office at 7am, seeing their sleep deprivation as a mark of toughness and dedication. We equate their long work hours with high levels of productivity. But this is mistaken: a lack of sleep affects every part of your brain, including those needed for any type of focused work or learning.
The link between performance and lack of sleep is especially clear in measures of academic performance. It probably isn’t a surprise for most of us that 75% of teenagers get less than the recommended eight hours of sleep a night. This trend is unlikely to be different in university students, for whom surveys tend to show a self-reported average of 6-7 hours of sleep per night. In large part, this chronic state of sleep deprivation is due to students staying up late to work (who hasn’t had an essay crisis at midnight?), then getting up relatively early. Getting through our day with this amount of sleep may feel normal to us, but it wasn’t always like this. Just a hundred years ago, 18-year-olds were sleeping two full hours more a night. And the evidence suggests that trying to get back some of those two hours may benefit our grades: getting just 43 extra minutes of sleep a night increased standardised test scores in American high school students by up to 25%, an increase in performance that would take hours of extra studying to achieve. It turns out that while well-rested brains are able to learn new information quickly, tired and under-slept brains are not good at retaining facts. In fact, they are shockingly bad at it. After one night of sleep deprivation, equivalent to pulling an all-nighter before an exam, we can remember 40% fewer facts learned the previous day. In an exam context, that would be the difference between failing and getting a first. It seems that when we are sleep-deprived, the part of our brains responsible for memory and learning (the hippocampus) shuts down, refusing to process new information. This may sound familiar to those of us who have found ourselves reading the same sentence in a textbook over and over again, feeling like nothing is going in. It turns out that just a little bit more sleep could make that process a lot less painful.
A better memory and increased lifespan are only two of the benefits of obtaining enough sleep. Add to that list increased emotional stability, better social interaction skills, increased athletic performance and more creativity, and it is easy to see how some sleep researchers are campaigning for sleep to be prescribed by doctors to improve well-being. So what can we do to try and get the benefits of a full night’s sleep? Although we may be tempted to reach for the sleeping pills, there is no evidence suggesting they actually increase sleep quality or well-being, and they may have actually have harmful effects. Instead, tips for healthy sleep include:
Sticking to a regular sleep schedule. With many of our schedules having become more flexible during lockdown, it’s become easy to sleep in late one day, then get up early the next. Our brains have a hard time adjusting to such rapid changes in sleep habits, so try to get up and go to bed at the same time every day, including weekends.
Avoiding (late) caffeine and nicotine. A cup of coffee at 3pm can make it hard for you to fall asleep at night. One in the morning is fine, but if you find yourself needing it to feel awake you may be sleep-deprived.
Avoiding alcohol late at night. This is a difficult one, but alcohol disrupts your deep dream sleep, which is essential to many of sleep’s beneficial effects.
Keep your bedroom dark, cool, and (most importantly) gadget-free before bedtime. Watching Netflix until right before bed is tempting, but may keep you awake longer.
Don’t take naps after 3pm. Late-afternoon naps can make it harder to fall asleep at night.
Following these tips may seem like a high price to pay for a good night’s sleep. In fact, the voice in my head telling me to just enjoy life while it lasts used to win against going to bed at 10pm. But knowing I may enjoy life a little more with just a bit more sleep may have turned that tide.