We all know we need sleep because we know how we feel when we don’t get sleep. We feel lethargic and cranky with an inability to focus. Yet, the importance of sleep is often marginalized, particularly in the United States, where over 50-million people are reportedly suffering from sleep disorders such as insomnia. Although experts haven’t quite determined why we sleep, research indicates quality sleep is an essential biological function, as vital as food and water, to both our physical and mental health.
The Four Stages of the Sleep Cycle
When we consider the quality of our sleep, we tend to focus solely on the quantity of sleep, but there is much more to enjoying a recuperative night of rest than the duration of time in which we have slept. An evening of sleep consists of four to six rounds of the sleep cycle, where each cycle lasts between 70 and 120 minutes. There are four stages to our sleep cycle, which are further broken down into two categories: rapid eye movement (REM) sleep, and non-REM sleep. The first three stages are non-REM sleep, where during the first stage, you begin to doze off. This stage typically lasts less than five minutes, however as the body has yet to fully decompress, you are still very easy to wake. As you transition into the second stage, your body temperature will decrease and your brain activity will slow down, as will your heart rate and respiration. The second stage can last up to twenty-five minutes, however, it does tend to last longer in your later cycles. During the course of the night, you will spend nearly half your time sleeping in the second stage of the sleep cycle. The third stage of the sleep cycle is commonly referred to as deep sleep, and research shows it is this stage where the body begins to recharge and recover. Though brain activity has decreased, research further indicates deep sleep contributes to insightful thinking and our ability to form memories.
We may not always remember our dreams when we wake, but we do dream every night. And although we can dream during any part of the sleep cycle, it is the final stage (REM sleep) where we dream most vividly. Our brain activity will increase, as will our heart rate and breathing, however, the body will experience temporary paralysis, so we cannot physically act upon our dreams. REM sleep is thought to be essential for cognitive functions (such as memory, learning, and creativity), and accounts for 25% of our sleep during one evening. The continual cycling through these four stages during one night of sleep is known as our sleep architecture.
Our Internal Clock
We have an internal clock (or sleep/wake cycle), which dictates when we are energized and when we are tired. This 24hr-cycle is known as the circadian rhythm. Various systems within the body follow the circadian rhythm, which is directly influenced by our environment, most notably – light. When we wake, we will become increasingly tired, and as the day moves on, the pressure to sleep will peak in the hours leading to bedtime. A variety of hormones are strongly connected to this circadian cycle, such as melatonin and cortisol.
Melatonin is a hormone made by the pineal gland, which helps you determine when it is time to sleep, and when it is time to wake. Cortisol is a naturally occurring stress hormone that plays a key role in the body’s response to stress, and by default, promotes both energy and alertness. These two hormones have opposing times when they peak – melatonin is at its highest levels during the night, and is nearly undetectable during the day. Cortisol peaks in the early morning, yet is minimal during the night. However, both hormones are sensitive to environmental factors, and can thereby affect your circadian cycle. As an example, melatonin secretion is suppressed due to retinal exposure to light, and increased stress or activity in the evening can stimulate the release of cortisol. As such, maintaining good sleep habits (as mentioned below) can keep the production of both melatonin and cortisol aligned with your circadian cycle.
How Sleep Affects the Body and Brain
As previously mentioned, during the first three stages of sleep our body temperature decreases, and our brain activity, heart rate, and respiration slow down. However, during the final stage (REM sleep), our brain activity increases, and our heart rate and breath quicken, almost to the rate as when we’re awake. Yet, all four stages provide a time for the body to heal, and for the brain to prepare for the upcoming day. But, what does sleep actually do for our body and our brain, and what happens when we are deprived of it?
Following numerous studies in the early 2000s, researchers (unsurprisingly) discovered sleep is linked to multiple brain functions, including concentration, productivity, cognition, and even our emotional and social intelligence. Which makes sense, right? We’ve all experienced at least one night of poor sleep, and did you find it easy to concentrate the next day? Or to perform a particular task? Or thoughtfully listen to a friend?
Specifically, the prefrontal cortex allows us to focus our attention, predict the consequences of our actions, and anticipate events within our environment. It is involved in learning and forming memories, and when we sleep, connections between newly learned material are both linked and solidified through communication between the prefrontal cortex and the hippocampus. Without an adequate amount of sleep, we cannot properly focus, we cannot properly learn, and we cannot properly form memories. Sleep deprivation also affects our amygdala, which is responsible for processing our memories, but also our emotions. It is for this reason that both anxiety and depression have long been linked to lack of sleep.
Sleep plays a key role in nearly all aspects of our physical wellbeing, which includes our cardiovascular health. Our heart is responsible for pumping blood throughout the body, which ensures all organs and tissue are properly oxygenated. During non-REM sleep, our heart rate decreases and our blood pressure drops by about 10-20%, which allows for the heart vessels to heal and rebuild. Without this required time to heal, our heart becomes strained, which can lead to a variety of health concerns such as high blood pressure, high cholesterol, heart attack, and stroke. In fact, one study found people sleeping less than six hours per night had a 20% higher chance of a heart attack, and in another study involving over 400,000 individuals, researchers found a strong correlation between sleeping disorders and heart failure.
Sleep deprivation can also affect our immune system, and our ability to fight off viruses. T-cells play a vital role in our immune system. When one of our cells has been infected by a virus, T-cells will activate integrins (a sticky type of protein), which attach to and kill infected cells. Studies have found when we get between seven and eight hours of sleep, T-cells activate higher levels of integrin. Additionally, the production of stress hormones (such as cortisol and norepinephrine) decreases while we sleep, which could otherwise affect the ability of the T-cell immune response to kill pathogens.
But, sleep doesn’t just affect our stress hormones. It also affects our hormones that control both when we feel hungry (ghrelin) and when we feel full (leptin). Ghrelin is a hormone produced and released primarily in the stomach, which both stimulates our appetite and promotes fat storage. Chronic stress can increase higher levels of ghrelin (which can lead to “stress-eating”), but research has found that even a single night of poor sleep can increase our levels of ghrelin. Leptin is a hormone released by fat cells, which sends signals to the hypothalamus in the brain. Its primary function is to help the body maintain a healthy weight, however, when we do not get an adequate amount of sleep, our leptin levels plummet. Left unchecked, this hormone imbalance of ghrelin and leptin can lead to an increase in fat storage, changes in body weight, and in more severe cases, obesity. Additionally, because poor sleeping habits affect our glucose metabolism, there is an undeniable correlation between sleep deprivation and type-2 diabetes.
Establishing Good Sleep Habits
We’ve established the unquestionable importance of sleep, but how do we ensure we get both enough sleep and quality sleep? Here are some recommendations for establishing healthy sleep habits:
- Decide on a reasonable bedtime, and stick to it (both during the week and on weekends)
- Maintain a comfortable temperature in your bedroom (not too hot)
- Ensure low lighting with either blinds, eye masks, or even blackout curtains
- Make sure your mattress, pillows, and sheets are comfortable and clean
- Avoid screens at least an hour before bed (cell phones, television, tablet, laptop)
- Avoid caffeine, alcohol, and snacks in the hours leading to bedtime
- Exercise during the day, which can help you wind down in the evening
There are also various prescription and over-the-counter medications to help with sleeplessness, however, they all have side effects ranging from digestion concerns to cognitive impairment. At Rx Remedies, our staff pharmacologist formulates concentrated, plant-based medicines for relieving anxiety, pain, inflammation, depression, but also insomnia.
We offer various full-spectrum sublingual tinctures with a highly sedating Indica terpene profile, specially formulated by our staff pharmacologist. However, we also provide multi-cannabinoid formulations (available in both tinctures and tablets) that not only include CBD, but also CBN, which has long been researched as a sedating cannabinoid. Specifically, our multi-cannabinoid SleepEZ tablet includes both CBD and CBN with melatonin, valerian root, and our sedating terpene blend. These products provide a plant-based alternative to prescription sleep aids, but without any of the side effects.
As we (hope) we’ve established, sleep is a biological necessity, and for the sake of our physical and mental health, we must prioritize it. It truly affects how our body functions on nearly every level. Along with proper nutrition and daily exercise, we simply cannot be our best selves without quality sleep.