The Importance of Sleep

Sleep is a complex activity that has a profound impact on mental, physical, and emotional health. During the deepest stages of sleep, the brain and body recover leaving you feeling recharged and able to perform your best. Sleep also improves immune cell function, regulates metabolism and hormones, and reinforces a healthy cardiovascular system. All these systems need to be restored to make the body less vulnerable to disease.

Unfortunately, sleep is often one the first things that is sacrificed when trying to fit more into 24 hours.

 

How the Sleep-Wake Cycle Works

Sleep is part of a 24-hour cycle known as the sleep-wake cycle or the circadian rhythm. This cycle is regulated by two main hormones, melatonin and cortisol. Ideally, melatonin peaks at night to make us sleepy while cortisol peaks in the morning to provide us with energy. Melatonin and cortisol have an inverse relationship; when melatonin is high, cortisol should be low. When either of these hormones get out of balance, our ability to sleep is affected. ⠀

One of the biggest influences on the sleep-wake cycle is light. Melatonin production is blocked at night when our eyes are exposed to light (especially blue light) from bright lights, watching TV, or playing on cell phones/tablets before bed. Even if you can fall asleep after these activities, it takes time for melatonin levels to rise delaying the onset of quality sleep. On the other hand, sun light first thing upon waking will help to regulate this cycle.

Other factors that impact this cycle and sleep quality include stress, physical activity, alcohol, noise, and food consumption. 

Does Your Sleep Need Improvement?

Answer the following questions to see if your sleep quality is optimal.  

  1. Do you have troubles falling asleep at night?
  2. Do you have difficulty waking up in the morning?
  3. Do you sleep less than 7 hours a night?
  4. Do you wake up once or more during the night?
  5. Do you sleep in a room with any light or noise?
  6. Do you wake up feeling tired?
  7. Do you wake up only with an alarm?
  8. Do you go to bed later than 11pm?
  9. Do you use medications (over the counter or prescription) for sleep?
  10. Do you need caffeine to feel awake in the morning?
  11. Do you snore, mouth breath, or grind your teeth?

If you answer yes to 2 or more of these questions, then there is room to improve your sleep quality.

You can also track your sleep objectively. A sleep tracking device will tell you how long you spend in each of the 3 sleep stages. These 3 sleep stages are:

  1. Light sleep – this is where you will spend most of your time during sleep. This stage should account for 60% of your total sleep time.
  2. Deep sleep – this stage is believed to be the most restorative type of sleep leaving you feeling refreshed and energized when you wake up. This slow wave deep sleep typically occurs during the first one-third of the night and should account for 20% of your total sleep.
  3. REM sleep – also known as rapid eye movement sleep, is where you experience most of your dreams. REM sleep increases as the night progresses and is longest in the last one-third of the night and should account for around 20% of your total sleep.

These sleep stages are characterized by many physiologic changes including brain activity, heart rate, blood pressure, sympathetic nervous activity, muscle tone, blood flow, respiration, and body temperature. Sleep tracking devices use your heart rate to determine what sleep stage you are in. You can look at the data from your device to see how long you are spending in each stage. Sleep cycles through all stages 4 – 5 times so the amount of time asleep will vary from person to person. Each cycle can last from 90-120 minutes meaning that 7-9 hours of sleep is optimal.

Consequences of Poor Sleep

Poor sleep affects your entire body, brain activity, mental health, and soul. Sleep disruption leads to an array of short- and long-term health consequences.

Short term sleep deprivation leads to increased stress responsivity, somatic pain, reduced quality of life, emotional distress, mood disorders, and cognitive, memory, and performance deficits.

Long term consequences include high blood pressure, high cholesterol, cardiovascular disease, weight related issues and obesity, type 2 diabetes, depression, and colorectal cancer.

Sleep is when the glymphatic system is most active. This system cleans the brain of all the waste produced and prepares it for the next day. When the glymphatic system is unable to clear the waste from the brain, it drives abnormal brain function and neurodegeneration.

These wide-ranging effects of sleep disruption are often interrelated and bidirectional with the risk factors below. For example, a poor night sleep leads to an increased stress response. An increased stress response heightens anxiety and worry about not being able to sleep, leading to a further lack of sleep.

 

Risk factors for sleep disruption are vast and can involve a combination of biologic, psychologic, and social factors. These factors include but are not limited to:

  • Stress, anxiety, depression
  • Hormonal imbalances (i.e., hypothyroidism)
  • Respiratory dysfunction (i.e., obstructive sleep apnea)
  • Metabolic causes (i.e., blood sugar imbalances)
  • Medication (i.e., antidepressants (SSRI’s, SNRI, TCA), stimulants (methylphenidates), decongestants, pseudoephedrine, thyroid medication)
  • Illicit drugs and alcohol
  • Environmental influences (i.e., shift work, noise, mattress, weather, partner, children, light pollution etc.)
  • Caffeine and nicotine
  • Chronic pain or movement disorders (i.e., restless leg syndrome, periodic limb movement disorder)

 

If you experience any of these factors that can impact sleep, talk to your naturopathic doctor or functional medicine practitioner to see what supportive measures can be implemented to support your health and wellbeing. Supporting sleep can be one of the best things you can do for your health!