Sleep is, hands down, THE MOST IMPORTANT recovery tool for the human body. It is often the most overlooked variable as well. In today’s high-octane society, outworking your competition (and often yourself) is the hallmark of success. Sacrificing sleep for this increased work capacity is often a badge of honor amongst high-achievers, “I only need 3 hours of sleep and then I’m good to go”. Prioritizing sleep has developed a sort of stigma associated with laziness. Nobody wants to seem lazy, therefore many proselytizing this idea that the less you sleep, the busier you are. The busier you are, the more success you see. This short-sighted decision is not only wrecking your cognitive performance but also your recovery capacity, stress resilience and predisposing you to a lot of serious health consequences. Alzheimer’s disease, cancer, diabetes and many mental health disorders are all directly linked to not just the hours of sleep we achieve, but the quality of those hours.
Let us examine the impact that sleep deprivation has on the human body and the scope of the problem in our society. Research has shown that by staying awake for a mere 19 hours, that the individual is as cognitively impaired as if you are legally drunk. If you go in for surgery, one of the most important questions you could ask is to your surgeon, “When is the last time you slept?”. In 1942, a Gallup poll showed that less than 8% of the population were surviving on less than 6 hours of sleep per night. When repeated in 2017, this had grown to almost 1 out of every 2 people. Why such a dramatic increase? Technology and occupation seem to be the most obvious reasons. We live in a highly electrified environment these days. Our eyeballs are assaulted with light almost 24 hours/day. Between our cell phones (most egregious offenders) and all other sources of artificial light, a very primal circuit in the brain, the Reticular Activating System is lit up like a Christmas tree. This circuit is responsible for mediating wakefulness and sleep-wake cycles. The only primer it needs is visible light stimulus from BOTH eyeballs to say, “HI, IT’S TIME TO BE AWAKE NOW”. Pro-tip: If you wake up in the middle of the night to use the bathroom or get a drink of water, KEEP ONE OF YOUR EYES CLOSED! Getting light stimulus from only one eye will make it exponentially easier to fall back asleep. This is a trick I have used myself for years and has made a huge difference. The second major variable is our occupations and the blurry lines between work and home life. Many of us have lost the clearly defined margins of when the workday begins and ends. We are constantly inundated with emails and after-hours responsibilities that trigger the stress/vigilance response that make getting a sound night’s sleep very difficult to attain. Nobody wants to give up their time with family or doing the things they love. With most of us, the first thing we give up is sleep.
Leading the discussion on the importance of sleep is Dr. Matthew Walker, a PhD in neuroscience and director of the Center for Human Sleep Science at the University of California, Berkeley. I recently discovered Dr. Walker’s work via a conversation he had with Joe Rogan on the JRE podcast. Even as a clinician, I was shocked at how little emphasis on sleep was built into my education. After listening to this conversation, I immediately picked up his book, Why We Sleep to better communicate these fundamental concepts to my friends, family and patients. To boil down the concepts presented in this book is a far greater challenge than my limited vocabulary will allow, however one statement sums it up well. “Humans are the only species on earth that deliberately deprive themselves of sleep for no apparent reason. In case you’re wondering, the number of people who can survive on five hours of sleep or less without any impairment, expressed as a percent of the population and rounded to a whole number, is exactly zero.” Coming from the world’s foremost sleep expert, this is a pretty clear statement.
All of this begs the question, “So, what am I supposed to do? Sleep all day and night?”. When asked about his personal practices and recommendations in a recent interview, Dr. Walker stated, “I give myself a non-negotiable eight-hour sleep opportunity every night, and I keep very regular hours: if there is one thing I tell people, it’s to go to bed and to wake up at the same time EVERY DAY, no matter what. I take my sleep incredibly seriously because I have seen the evidence. Once you know that after just one night of only four or five hours’ sleep, your natural killer cells – the ones that attack the cancer cells that appear in your body every day – drop by 70%, or that a lack of sleep is linked to cancer of the bowel, prostate and breast, or even just that the World Health Organisation has classed any form of night-time shift work as a probable carcinogen, how could you do anything else?”. Among these insights, Dr. Walker’s research points out some very alarming statistics:
- An adult who only receives 6.75 hours of sleep per night can be predicted to live into their early 60’s without medical intervention (yikes).
- Over 2/3 of the population of developed countries achieve the recommended 8 nightly hours of sleep.
- If you jump behind the wheel of a car with less than 5 hours of sleep, you are 430% more likely to be involved in an accident.
- A hot bath before bed can help you fall asleep. However, not because it makes you warm. The heat from the water forces dilation of the blood vessels, resulting in a small decrease in core body temperature which the body needs to successfully initiate sleep.
One of the more important functions of sleep occurs in the deeper Rapid Eye Movement (REM) stage. The science has shown us that, not only is REM sleep essential for the consolidation and storage of memories and neurological integration but is also the brain’s primary waste removal period. Toxic metabolic byproducts that accumulate in the spaces between neurons and in the cerebrospinal fluid channels must be actively transported across the blood-brain barrier. If some of these protein aggregates, namely beta amyloid, are not transported out by the brain’s waste removal system, they will accumulate and form plaques which destroy the surrounding neurons. The toxic accumulation of beta amyloid plaques is the hallmark of Alzheimer’s Disease. There has now been evidence that points toward lack of sleep being the single-most causative factor to predispose one to developing Alzheimer’s Disease. Even more so than genetic predisposition. Let that sink in for a moment. More than 20 large scale studies all report the same clear relationship: the shorter your sleep, the shorter your life. For example, one of these studies showed that “adults aged 45 years or older who sleep less than six hours a night are 200% more likely to have a heart attack or stroke in their lifetime”.
By now, I hope it is clear that a solid 7-8 hours of sleep per night might be the most important life and health hack that we are all overlooking. So go ahead, go to bed early! Sleep in on the weekends! Stop beating yourself up about giving your body what it so desperately craves. Sweet dreams, my friends!
Content provided by Dr. Tyler Crooks