Why We Need Shut-eye: The Many Benefits of Sleep

In my series on slumber, we’ve learned enough about sleep to give us a healthy level of concern if we don’t get adequate amounts of it.

Research has revealed that being underslept leads to poorer job performance and negatively impacts brain health, cognitive function, emotional balance, relationships, and overall wellness. Without sufficient shut-eye, neurons in the brain become overworked and thinking, memory, and concentration is impaired.

Sleep is also needed for cardiovascular, hormone, metabolic, immune, brain, and emotional health. In fact, risk for diseases and imbalances in these categories increase when one is sleep deprived.^{1-28, 33}

The theories on why we sleep support the fact that we need seven to nine hours of slumber to achieve its benefits and obtain optimal wellness. Around this amount of sleep is as vital for health as nutrition, movement, self-care, relationships, and socio-economic factors.

The bottom line is that without shut-eye, our body and mind simply can’t recharge and function at its best.

In this article, I conclude my sleep series. Topics include:

• the stages of sleep
• the 4 sleep cycles
• chronotypes and a quiz to find out yours (what they are, the four types, and how they impact lifestyle)
• sleep disorders
• 11 tips for enhancing slumber from a neuroscientist
• aromatherapy for sleep

Knowledge of these aspects can help you understand that skimping on sleep can disrupt reparative processes and functions in your brain and body. Furthermore, understanding your particular chronotype (e.g., night owl vs. early bird) can be helpful to adjust the timing of your lifestyle interventions and to live a more vital life.

Let’s get started.

An Overview of the Sleep Phases and Cycles

Our body follows a specific sleep cycle, which is divided into four stages, each with distinct timings, amounts, and functions: ^{4, 9, 16-17}

• Stages 1-3 are known as non-rapid eye movement (NREM) sleep.
• Stage 4 is known as rapid eye movement (REM) sleep.

Stage three of sleep is the deepest and a time of intense repair and memory consolidation. The most brain activity, memory consolidation, and emotional processing is believed to occur during REM sleep. ^{4, 9, 16-17}

Most people go through four to six non-uniform cycles of sleep a night. Each cycle ranges from 90-120 minutes. NREM constitutes 75-80% of the duration. During the first half of the night, sleep is the deepest and with each cycle, the amount of deep sleep decreases. ^{4, 9, 16-17}

The Four Stages of Sleep

Below, I provide a bit more detail on the four stages of the sleep cycle. ^{4, 9, 16-17, 35-37}

Stage 1 (1-10 minutes)

Stage one is the transition phase from wakefulness to sleep. During this light non-REM sleep, heart rate, breathing, eye movements, and brain waves slow down. Muscles relax and may twitch. The brain is still relatively active, and it produces theta waves.

Stage 2 (25 minutes, about 50% of sleep time)

In this stage, one is moving into deeper non-REM sleep. Greater muscular relaxation occurs, eye movements cease, and body temperature lowers in this phase.

During this time, sleep spindles are evident. These are bursts of rapid, rhythmic brain wave activity. They are thought to be a feature of memory consolidation and cortical development

Stage 3 (30-60 minutes)

Stage 3, non-REM sleep is the deepest phase of sleep. This makes awakening at this point difficult. Heart rate, breathing, and brain wave patterns (delta) become regular at this time.

Stage 3 is when the body starts to make physical repairs. Declarative memory (general knowledge, personal experiences, ect.) are also consolidated in the brain in this phase.

Stage 4 (1-60 minutes)

Stage 4 is known as REM sleep. “REM” is the term for “rapid eye movement.” This phase of slumber is appropriately named because the eyes move quickly and rapidly from side to side at this point in the cycle.

During REM sleep, physiology becomes more erratic. Blood pressure, breathing rate, and heart rate become irregular. It is also the phase most associated with dreaming, though dreams can happen in other stages. Both declarative memory and emotional memory processing occurs in the brain at this time.

“Sleep paralysis,” where muscles lose tone, occurs here as well. Initially REM lasts 10 minutes but progresses in length to one hour as we cycle through the sleep phases.

As you can see, each phase of sleep has a function, so disrupting our length of sleep time can alter sleep cycle patterns. Therefore, making sure we optimize our resting time is paramount to allow our brain to hit all the stages. ^{4, 9, 16-17, 35-37}

What About Chronotypes?

What about sleep timing? Most scientists agree sleeping at nighttime is best, but not everyone may be “wired” to fall asleep at 10pm and wake at 6am. This is where chronotypes come in.^{29, 41}

According to the Sleep Foundation:

Chronotype is the natural inclination of your body to sleep at a certain time, or what most people understand as being an early bird versus a night owl.

In addition to regulating sleep and wake times, chronotype has an influence on appetite, exercise, and core body temperature.

It is responsible for the fact that you feel more alert at certain periods of the day and sleepier at others.

Sleep chronotypes are linked to circadian rhythm. Although our sleep-wake cycle can be “trained” by a strict schedule, the underlying chronotype is more permanent. Chronotypes do not alter sleep requirements, but they can make it hard for people to adapt:

… a natural night owl may be able to wake up at 7 am every day for work, but they may not be productive until later in the day. Conversely, an early bird may wake up bright and chipper for their 7 am shift, but then start to feel sleepy already in the late afternoon.

If most adults need between seven and nine hours of sleep a night, this is usually much easier to accomplish for an early bird than for a night owl, who has trouble falling asleep before 1 am. For this reason, night owls have historically faced more difficulty adapting to typical work schedules.²⁹

Scientists consider it very difficult or impossible to change ones chronotype. Age, genetics, and gender all influence one’s preference for bedtime.

Chronotypes may also influence risk factors that are reported in science. For example, if one is a “night owl,” studies that determine going to bed earlier is better for heart health may not be as applicable for those individuals. After all, being a smaller part of the population, night owls may not be accurately represented in the trial population.  This was found in a recent study with shift workers. One researcher stated:

“There are health implications for night shift workers, but our study shows that these vary between individuals dependent on their chronotype, and that should be considered when designing interventions.”

Discover Your Chronotype and Optimize Your Lifestyle

The “Sleep Doctor,” Dr. Michael Breus, literally wrote the book on chronotype! He has a wonderful chronotype quiz divided into four categories. These include:

• Lions: Our early birds. They tend to have high energy, are interested in fitness, and have a hard time staying awake and attending night events.
• Bears: These make up 55% of population. They work great in our culture’s determined 9am-5pm work day and get things done. They are usually fun to be around and make good friends.
• Wolves: They are the misunderstood night owls. Wolves find it hard to fall asleep before 11pm-12am and struggle with fitting into society’s schedule. They tend to be creatives who get their inspiration to write and create at 2am!
• Dolphins: These poor unfortunates want to wake up like a lion, but have genetically erratic sleep patterns. This makes it hard for dolphins to get into deep slumber and feel rested to get-up-and-go early. Evolutionarily, they may have been the “night watchers” over the tribe.

Dr. Braus feels that when you know your chronotype, you can work with it to optimize timing of lifestyle factors, such as exercise and eating patterns. His book offers suggestions for each chronotype.

Here’s a quick video from his website:

Sleep Disorders and Assessment

What about when one can’t sleep?

There are six major categories of sleep disorders that are diagnosed by a specialist. These include:^33,38

• insomnias, which affect 10-30% of the population
• sleep-related breathing disorders
• central disorders of hypersomnolence (increased time sleeping)
• circadian rhythm sleep-wake disorders
• parasomnias (disordered sleep behaviors)
• sleep-related movement disorders.

If you are struggling with sleep, it is best to get support for better slumber from a professional who can determine the cause.

11 Tips for Better Sleep, According to the Leading Sleep Neuroscientist

Now that we know how vital sleep is, if we don’t have a disorder, what are some general ways to get more of it?

Dr. Walker is a neuroscientist and founder-director of the Center for Human Sleep Science at the University of California, Berkeley. He is also author of the international bestseller book, Why We Sleep (2017). He recently offered 11 general tips for better sleep in a blog. These include:

1. Have a regular nighttime routine. By sticking with a consistent bedtime and wake time, your circadian rhythm (sleep and wake cycle) and hormones are more balanced. This also prevents physical and mental fatigue from “catch up sleep,” which he states doesn’t effectively alleviate the “sleep debt” compiled from previous evenings.
2. Avoid late night workouts. Try to end exercise three hours prior to sleep so that the brain and body has time to unwind.
3. Reduce caffeine and nicotine consumption. Caffeine is a stimulant that helps one stay alert by blocking the compound adenosine, which makes you feel sleepy. Nicotine is a also stimulant and can prevent deeper phases of sleep needed for healing and rejuvenation. For these reasons, it is best to avoid nicotine and to try to consume caffeine earlier in the day, especially if you’re a slow metabolizer of it.
4. Avoid alcohol. Although alcohol is a depressant, it robs you of REM sleep, the deep slumber your brain requires for optimal restoration. Too much alcohol can also cause one to wake up more frequently and impact breathing rate. This deteriorates sleep quality.
5. Avoid eating light at night. Heavy meals and too many liquids before bed can cause tummy upset and frequent bathroom breaks that can interrupt sleep.
6. Check your medications. Some medications, such as heart drugs can impact your sleep.
7. Create time to unwind. Having a relaxing ritual before bed can help to signify to your brain that it is time to wind down. Writing in a journal to get out emotional upsets before bed can be helpful at this time to process emotions that may keep one awake.
8. Take a warm bath. Your body does best when it is a bit on the chiller side for sleep. A warm bath diverts blood flow, so that after your warm and toasty, your body releases heat and cools you down.
9. Don’t take your devices to the bedroom. Even just having a phone in the room can signal your brain to be on alert. Consider getting an old-school alarm clock if you use your phone to wake up.
10. Glance at the morning sun and dim the lights at night. Aim to peer (indirectly) into morning sunlight within 30 minutes after waking. Also, turn down the lights at night. These cues optimize melatonin secretion and can help you to balance your circadian rhythm.
11. Don’t just lie there. If lying in bed without sleeping makes you anxious, it’s not restful. Get up and do something calming until you unwind and then get back in bed and enjoy your slumber.

Other naturopathic tips for restful slumber include mindfulness-based practices, aromatherapy, and emotional freedom technique (EFT).

I review more about using essential oils below.

Aromatherapy and Sleep

Lavender is well known and researched for its ability to assist one into slumber. It is validated to calm the brain and body. Several studies show that it does modulate cortisol, the “stress hormone.” It was also shown in a small trial to enhance melatonin.

Other oils that may benefit sleep will be most effective if the underlying cause is addressed. For many, stress and worry keep them awake. In these cases, other essential oils that lower and regulate cortisol, including clary sage oil and  bergamot oil, may be helpful.

Summary on Sleep Stages, Sleep Cycles, Chronotypes, and Optimizing Sleep

I this article, I discussed:

• the stages of sleep
• the 4 sleep cycles
• chronotypes (what they are, the four types, and how they impact lifestyle) and a quiz to find out yours
• sleep disorders
• 11 tips for enhancing slumber from a neuroscientist
• aromatherapy for sleep

These are important to understand for the following three reasons:

1. Knowledge of the sleep cycles can help you understand that cutting sleep short can interrupt your brain repair and restoration and emotional and declarative memory consolidation.
2. Learning your particular chronotype (i.e., bear, lion, wolve, or dolphin) can be helpful to optimize the timing of your lifestyle interventions.
3. Having a regular sleep schedule and routine which relaxes the body and brain is imperative to optimizing sleep and your overall health.

If you are having trouble sleeping, all is not lost. Along with conventional care, a naturopathic and functional medicine doctor can help to further address the underlying issues of why you can’t get sleep. They can also support and revitalize the body and brain from sleep deprivation as sleep is improved.

What did you learn about sleep?

What’s your chronotype? Take the quiz and share below.

Naturopathic Medicine and Holistic Resources for Hormonal, Mood, and Digestive Support

• Free resources and more education on essential oils and mind-body wellness are available to you here.
• An Integrative Mental Health and Stress Resource Guide.
• Tools for coping with isolation and separation.

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Many blessings.

References:

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