Sleep is essential for good health. It is a well established fact that chronic sleep deprivation can lead to immune system disfunction, chronic disease conditions like diabetes, obesity, high blood pressure, depression, anxiety, and even death. Yet, many of us (one out of three Americans, in fact) tend to put little emphasis on sleep. According to data published by the CDC, sleep problems, whether in the form of medical disorders or related to work schedules or a fast-paced, high-pressure lifestyle, are pervasive in our modern society. (1)
Sleep and Your Immune System
When you sleep your immune system releases proteins called cytokines, some of which actually help to promote sleep. These cytokines assist your body in overcoming infections as well as recovering from stress. Sleep deprivation may decrease production of these protective cytokines.
Additionally, nocturnal sleep, especially slow wave sleep or deep sleep, prevalent early in the night, promotes the release of growth hormone and prolactin, while anti-inflammatory actions of cortisol and catecholamines (epinephrine and norepinephrine) are at their lowest levels. This endocrine milieu during early sleep supports the proper functioning of the adaptive immune system by promoting the interaction between antigen presenting cells and T cells, and the formation of long-lasting immunological memories. This helps the body create a more robust defense against infectious organisms like viruses and bacteria.(2), (3)
In a fascinating book I recently read, Why We Sleep, Unlocking The Power of Sleep and Dreams, the author, Mathew Walker, says that consistently failing to get six or seven hours of sleep considerably weakens your immune system and increases one's risk of cancer, high blood pressure, coronary artery plaque accumulation and blockage due to an increased production of reactive oxygen species (ROS).
Rest and Recovery
During a regular night's sleep, you go through several 90-minute cycles consisting of four distinct phases. Each of those phases plays an essential role in maintaining your mental and physical health. Sleep optimizes our learning capacity and memory as well as our emotional composure. Have you noticed how weepy and on edge you feel after a sleepless night?
The four stages of the sleep cycle can be divided into two main categories: non-rapid eye movement (NREM) and rapid eye movement (REM). During NREM and REM sleep your eyes are either still or moving rapidly as "your brain progresses sequentially through each stage: wake, light sleep, deep sleep, rapid eye movement (REM), and repeat."(4)
NREM Sleep
NREM sleep happens mostly in the early stages of the night (typically between the hours of 10 PM and 2 AM). This phase includes the periods of wakefulness, light sleep and deep sleep. Deep sleep is the most restorative type of sleep, promoting muscle growth and repair as well as waste removal in your brain. (4)
Deep sleep is characterized by slow brain waves, lower heart rate and blood pressure, and an increased blood flow to muscles. In other words, we need deep sleep for proper rest and recovery. Now you see why it is important to go to sleep before 10 PM and not cut short this stage of your sleep cycle. If you do, you wake up feeling groggy, cranky and sore.
REM Sleep
REM sleep is characterized by rapid eye movement and extreme brain activity. REM sleep typically happens in the second half of the night or in the later stages of the sleep cycle. When you don't get enough sleep or wake up very early, you do not allow your brain to properly consolidate and convert memories from short to long-term and move them from the hippocampus to the cortex. Moreover, lack of sleep prevents our brain from strengthening its neural connections, which can lead to numerous mental, physical, and emotional problems.
REM sleep is essential to re-energizing your mind and is associated with dreaming, memory consolidation, learning, and problem solving. (4)
Looking at the figure below, you can roughly estimate how long each stage of the sleep cycle should last depending on how many hours of sleep you get. This of course will vary based on your daily habits, diet, stress and exercise level as well as on your body's ability to rest and recover.
Tools for Optimizing Sleep Quality
The quality of your sleep can be disrupted by so many factors. I find that tracking my sleep cycle as well as heart rate variability, and recovery index helps me make better choices throughout the day.
I personally use the OURA ring because it provides real-time feedback on how my body is functioning and helps me shift my daily habits in order to get a more restorative night's sleep. The best part is that the OURA continues to collect data even when in airplane mode, so you can use it without being exposed to bluetooth radiation 24/7.
Based on my research and personal experience, I have discovered a few daily habits that can immensely improve sleep quality and if properly implemented, can have you wake up rested, energized, and ready to conquer the world!
If you have time, you should also listen to this webinar presented by the Great Plains Laboratory which goes into great detail on how to optimize sleep, reset your circadian rhythm, and heal your body and brain from chronic sleep deprivation. Fascinating stuff!
Light & Dark Balance
The light and dark balance is one of the most important factors affecting sleep duration and quality. We are exposed to artificial light 24/7, which drastically disrupts our 24-hour brain clock. It is not just blue light that affects us, but all artificial source of lighting can stress the pineal gland and cause the brain to think it is daytime. This inhibits REM sleep, according to the book Why We Sleep, Unlocking The Power of Sleep and Dreams.
Dim lighting during the night and limit your exposure to screens and bright fluorescent lights, which significantly reduce melatonin production.
Inversely, exposure to bright, full-spectrum sunlight in the morning and during the day can be very beneficial for resetting your circadian rhythm and improving sleep quality. If you don't have access to natural sunlight, depending on where you live and what time of year it is, 15-20 min of infrared light therapy would do just fine.
Intermittent Fasting
Diet has an enormous impact on sleep. Eating too much or too little during the day can affect your endocrine system and your body's ability to rest and recover. I often tell my clients that one of the most powerful practices they can implement to improve health, energy levels, and sleep quality is intermittent fasting or time restricted eating (TRE).
Time restricted eating allows your body to properly digest and metabolize food and to rest fully when it is time to do so. To practice TRE, you should stop eating ideally 3-4 hours before sleep.
Additionally, you should fast for at least 12 hours overnight so that your digestive and detox systems have ample time to perform their functions efficiently. Let's say, your last meal of the day is at 7 PM, try not to eat again until 7 AM the next day. See how you feel after a week of doing this.
Reduce Caffeine
Caffeine tricks your brain into thinking it is not tired by blocking the adenosine receptors in the brain. Adenosine is a neurotransmitter that accumulates in the brain during the day in order to make you tired and sleepy at night. Without caffeine, adenosine binds to receptors that send sleepiness signals throughout your body. However, caffeine is a small molecule able to cross the blood brain barrier. Once it enters the brain, it fits in the adenosine receptors and blocks the sleep signals of the brain.(5),(6)
You can have your coffee in the morning, but avoid caffeine consumption later in the day, especially after lunch.
The half life of caffeine is 5-7 hours, which means that it may take your body that many hours to clear half of the caffeine in your system. In addition to blocking the action of adenosine, consuming caffeine later in the day can increase your heart rate, blood pressure, and cortisol resulting in poor sleep and inability to fully rest. (5),(6)
Avoid Alcohol Too Close to Bed
Alcohol can be calming, right? Well, not so much.
Perhaps, after a long day of work, it feels nice and relaxing to sit down and unwind with a glass of wine, but the closer to bedtime you drink, the more your sleep will suffer.
Alcohol suppresses REM sleep (responsible for memory, learning and emotional health) and induces non-continuous, interrupted sleep, which makes us feel very groggy and sluggish when we wake up.
Too Much Exercise?
Regular exercise is very beneficial for our health and we need continuous movement throughout the day to improve blood circulation and metabolic function.
That being said, everything in life is a mater of balance. Exercise, especially a high intensity workout, too late into the evening can raise your cortisol and make it difficult to relax and unwind.
Exercise can increase your body’s prioritization of deep sleep the night after an intensive workout, inhibiting REM sleep. You may wake up feeling fatigued, foggy, and unable to concentrate. (4)
CBD Oil {Bonus Hack}
CBD oil has been covered a lot in the media lately for its potential to treat a myriad of chronic conditions, such as epilepsy, anxiety, depression as well as chronic pain.(7)
Some studies also suggest that CBD may help with both falling asleep and staying asleep.
I personally take a micro-dose of about 10-16 mg of cannabidiol before going to sleep and have discovered that it helps me get more restorative sleep by boosting my deep and REM sleep. There are some side effects associated with CBD supplementation, including fatigue, irritability, and GI upset. Every person responds differently to the active compounds in CBD, so it is important to evaluate efficacy and dosing on an individual basis.
There are many CBD brands being sold as supplements today. Currently, the FDA does not regulate the safety and purity of dietary supplements, so when purchasing CBD products, you have to do your due diligence and investigate the source and manufacturing methods. Also, look for other ingredients listed on the label that may be actually more harmful than good.
I use a liposomal formulation from a company called Quick Silver Scientific because I trust the quality and effectiveness of their products.
As you can see, sleep is very important not only for optimal health but for our survival. Thanks to our modern, fast-paced lifestyle, many of us have de-prioritized sleep and labeled it a "waste of time." Unfortunately, our physical and mental health deteriorates as a result, and the older you get, the more irreversible the damage is.
If you want to live a long and healthy life, making sleep a priority is an absolute must. Start implementing some or all of the suggestions outlined above and see if you notice a difference.
Sleep Well ♥