Part 1 Sleep is Critical - Why Do We Need Sleep?
Part 1 of 4
While stating so is a bit clichéd, we spend roughly a third of our life sleeping. So, why do we need sleep?
From the literature, we know getting enough and good sleep is critical to good health. Poor sleep leads to increased risk for multiple issues, including all cause death, while lowering productivity and emotional well-being. Why has sleep been ignored for so long? Why doesn’t the science of sleep get more attention? Join us this week with an intro to sleep as part of our four part series touching base on why we have added the OURA ring to our collection.
Consequences of poor sleep result in a myriad of physical and mental health issues affecting such a large percentage of the population that it is almost unbelievable that we are not more aware of it. I have heard both Donn Posner, Ph.D., clinical associate professor of psychiatry and behavioral sciences at the Stanford University Medical Center and Matthew Walker, Ph.D., professor of neuroscience and psychology at UC Berkley mention in recorded talks and lectures that the average MD gets 30 minutes of schooling on sleep, which is such a low number, it seems improbable two highly respected professors would make it up. Both have also commented that if the deleterious effects of lack of sleep were instead reframed as the consequences of something like diabetes, with the number of afflicted being the same, we would be in a full panic at the epidemic.
Many of you following various podcasts and blogs with the topic on maximizing human health span and longevity will know that awareness on sleep issues is starting to thankfully “trend”. I am by no means a pioneer here but am learning about this far before it has gone to mainstream acceptance. Perhaps because the issue is personal to me, but I’d like to think that because of its relevance to everything else I am pursuing, I needed to start emerging myself into the collective knowledge and understanding of sleep, its importance, and how it is connected to our health and aging.
For those looking for my breakdown, this will be a four part series. For others looking for further dives in, Peter Attia’s “The Drive” has a several part interview with Matthew Walker on sleep, and an ask me anything (AMA) at his site peterattiamd.com. Rhonda Patrick has more than one talk on sleep on her podcast at foundmyfitness.com. There are good talks on YouTube, such as this with one Prof. Donn Posner and Matthew Walker has his own site, Sleep Diplomat.
We’ve all heard the anecdotes of the geniuses or high-powered CEOs that need seemingly little sleep. While it is perhaps accurate that different people need different amounts of sleep to function effectively, our fixation on this as a talent or special ability has led to a culture of pushing the envelope, attempting to sleep less and less in the belief that it will allow more accomplishments.
I’ve learned this from experience. While I have struggled with sleep issues throughout my life, which I have detailed in my Hydrogen and Sleep article and my Caffeine article, no matter how hard I try, how much effort I put in, I cannot sleep 8 hours a night for days on end. I will just lay in bed, awake and restless, and the over rest makes me sluggish and lazy.
I seem to operate best on between 5.5-7 hours of sleep, depending on how active I am and how much sleep I have logged away the past few nights. I’ve been tracking this with my OURA ring, which we are now an affiliate for (and will detail the benefits later in this series), and previously did this with my Fitbit as mentioned in the “Hydrogen and Sleep” article. My “readiness” hits a high level even after 5.5 hours.
Even though I am “blessed” with needing less sleep than most others and I can operate for days on end with much less than 5.5 hours a night, that wasn’t “good enough” for me in my younger years. Even just a couple of years ago, I treated sleep as an annoying after thought. I fantasized about the day pharmaceuticals would allow me to be awake 24 hours a day with no serious consequences and all of the production I would accomplish, the learning and knowledge I could pursue, and the life I could live.
I would typically force myself up to start working, writing emails, and writing notes the second I rose from a light sleep, sometimes in the middle of the night. When friends, family, and colleagues would ask if I ever slept, or needed to, I would joke that “sleep is for the weak”. This bravado is not unique to me and seems to be quite prevalent in many industries and professions. ER doctors and residents, for instance, may be expected to get 2 hours or less of sleep in a night in small naps.
Why We Sleep
Many incorrectly believe that sleep is a time when our mind and body shuts down. However, sleep is actually an active period where many necessary functions take place. During sleep, our body works towards restoration, strengthening, and also completes important processing. While we do not yet know exactly why we need so much sleep and why it is so important, we know a couple key points: it has a function and virtually all species have evolved to require extraordinary amounts of time in slumber.
One important role of sleep is to store and sort through our memories. According to The National Sleep Foundation
“As we go about our day, our brains take in an incredible amount of information. Rather than being directly logged and recorded, however, these facts and experiences first need to be processed and stored; and many of these steps happen while we sleep. Overnight, bits and pieces of information are transferred from more tentative, short-term memory to stronger, long-term memory—a process called "consolidation." Researchers have also shown that after people sleep, they tend to retain information and perform better on memory tasks. Our bodies all require long periods of sleep in order to restore and rejuvenate, to grow muscle, repair tissue, and synthesize hormones.”
Another leading theory on why we sleep has to do with energy conservation. The hypothesis follows that our body needs to prepare for the following day. Sleep allows us to replenish hormone and neurotransmitter levels, maintain important protection mechanisms like the immune system, and repair damage to cells and tissues.
In a study published in Nature Communications earlier this year researchers studied DNA repair mechanisms within the chromosomes of zebrafish embryos by genetically engineering them to have fluorescent chromosomes inside their neurons. Researchers noted that double strand breaks were static during waking hours, but when asleep, DNA damage began dissipating. Further, by manipulating the zebrafish to keep them awake (such as tapping on the glass), the rate of DNA damage increased. The study’s authors concluded:
"Despite the risk of reduced awareness to the environment, animals -- ranging from jellyfish to zebrafish to humans -- have to sleep to allow their neurons to perform efficient DNA maintenance, and this is possibly the reason why sleep has evolved and is so conserved in the animal kingdom," Prof. Appelbaum.
Stages of Sleep
Stage 1 Non- Rapid Eye Movement (REM) Sleep: The first stage of sleep may only last 5-10 minutes, and it is very easy to wake from it. Personally, one of my biggest sleep issues is a “falling” sensation when I first begin to fall asleep. I will often wake up startled, heart throbbing, moments after dozing off. This is common, but frustrating, and is called a “hypnic jerk”. Provided you do not “jerk awake”, your heart beat will begin to slow as will your breathing.
Stage 2 Non-REM Sleep: The second stage of sleep further prepares you for deep sleep. Your breathing will continue to slow and your heart beat will lower even further, and your muscles relax. Your brain starts to produce a slower wave frequency known as sleep spindles.
Stage 3 Non-REM sleep: Deep sleep is critical and without it you may not feel properly rested in the morning. During deep sleep, your heartrate will drop to its lowest point and your breathing will slow even further from Stage 2. Your muscles become completely relaxed and your brain produces something called delta waves. It is incredibly difficult to rouse someone during deep sleep. This is the time where the body repairs and regrows tissues, builds bones and muscles, and strengthens the immune system. As we age, we tend to get less deep sleep. Aging is also correlatively linked to shorter sleep duration. This does not necessarily mean we need less sleep as we age or are incapable of achieving it.
Stage 4 REM Sleep: REM typically begins roughly 90 minutes after you fall asleep. The first REM period of sleep tends to last as little as ten minutes. However, each later stage lasts longer and your final REM stage during a night’s sleep can last as long as an hour. While your heart rate and breathing slow progressively through the first three stages of sleep, during REM sleep they speed up. This is the time in your sleep cycle where dreams occur, often intensely, as your brain is at its most active. It is believed that during REM sleep your brain processes and stores information, and forms procedural memories or memories on how to conduct tasks (as opposed to memorizing information). We tend to get less REM sleep as we age. An important study published last week showed that uninterrupted REM sleep is needed for amygdala adaptation and reactivity, perhaps necessary to deal with emotional trauma.i
Next week, chronotypes and why they are important, and the consequences of improper sleep.