The Science of Sleep

Legs Laid On Bed

Sleep is something we all do, it’s an essential body function that all humans and animals take part in. In fact, humans on average spend a third of our lives asleep.

However, not all sleep is equal - you’ll know this if you’re somebody that struggles to get a quality nights’ sleep! In this blog we explore what happens to our body during our hours asleep, how circadian rhythms affect our sleep, and how CBD can play a role as a sleep supplement. 

Why Do We Sleep?

Sleep is a complex biological process that keeps us alive and helps to form and maintain pathways in our brains. It allows our mind and body to recharge and is as natural to humans as breathing and blinking. It’s also as important as food and water in our survival and has a huge effect on our daily function. 

Neurotransmitters play a big role in falling asleep and staying awake. Put simply, neurotransmitters are the body's chemical messenger system. They send and receive information in the form of chemicals and hormones (such as serotonin, and dopamine) to different areas within the body. They let the body know that it’s time to wind down or wake up. This messenger system can be influenced by several outside factors and getting it to function at its optimum is an art in our modern world.

It was previously thought that when asleep we are inactive, that not much is really going on. Now we know that not to be true. In fact, the body and brain are working extra hard to restore and repair anything that isn’t right or is no longer needed. It’s thought of as a “housekeeping” exercise because it removes toxins that build up in the brain throughout our waking hours.  REM sleep is thought to enable critical cognitive abilities, such as memory formation, whereas non-REM plays a role in ensuring brain function whilst awake.

Sleeping affects both our physical and mental health, as well as playing a role in growth, in supporting our nervous system and in general wellbeing. In recent years, scientists have learned a lot about sleep, but there’s still so much that isn’t known, and the actual biological reason for why we sleep is still debated, however there are a few theories.

Theories about Sleep.

The first theory is inactivity theory; that if creatures are inactive at night, they are less likely to die, due to less chance of injury in the dark, or getting hunted. As such, evolution meant that there was a lot of survival benefit to being inactive at night.

Energy conservation theory suggests that because we use a lot more energy in the daytime – eating, moving, thinking etc. – sleep is there to reduce our need for energy, especially during the evening when hunting for food is less effective. The fact that our bodies’ metabolism decreases during sleep supports this theory.

The third theory is restorative theory. It’s the idea that sleep is a reparative activity, one that cleanses and replenishes the bodies’ cells that have become depleted throughout the day. Because bodily functions like growth, muscle repair, and protein synthesis occur during sleep, this theory has been backed by many findings.

Finally, brain plasticity theory states that sleep is needed for the brain to function properly; sleep occurs because we need it to reorganise our neural pathways, and to grow the brain. Infants sleep around fourteen hours per day, because sleep plays an integral role in developing infants and children’s brains.

Evolving Sleep Patterns.

What scientists do agree on, is that there are four stages of sleep that happen during the night, and they fall under either REM or non-REM sleep. The first three stages are non-REM and usually occur in the first half of the night, whereas REM sleep is usually the second part of the night.

Stage one is a short, transitory sleep cycle, and is usually when dozing off. In stage two the body and mind begin to really relax and start settling down. It’s still relatively easy to be woken in these two stages. Stage three is still non-REM but is deep, and when a lot of the recovery takes place. Brain waves, breathing and heart rate are all slower during this cycle. The fourth and final stage is REM and in this stage the brain, breath and heart rate rise to nearly where they would be when awake. Each sleep cycle lasts around 90 minutes but can be between 70 and 120 minutes, so certain cycles can be repeated depending on length and if woken.

It’s worth noting that over time, and with the prevalence of technology, our sleep patterns in general have changed. In the book, Wintering, author Katherine May talks about how before the industrial revolution, our night-times looked very different in that we used to have second sleeps.

“It was normal to divide the night into two periods of sleep: the ‘first’, or ‘dead’, sleep, lasting from the evening until the early hours of the morning; and the ‘second’ or ‘morning’, sleep, which took the slumberer safely to daybreak. In between, there was an hour or more of wakefulness known as the ‘watch’ in which ‘families rose to urinate, smoke tobacco, and even visit close neighbours.”

Today, how much sleep we need depends on many things including our age and our personal circadian rhythm and ‘chronotype’ – so it’s worth taking the time to understand more about what works for you.

Circadian Rhythms And Sleep.

When you understand more about your biological programming, you can start to work with your body, rather than against it to really optimise your sleep.

Sleep (and general health!) is heavily influenced by our circadian rhythms, which is the body’s internal clock. Our brain receives signals based on our environment (things such as light and dark) and this activates hormones, body temperature and metabolism with the aim of either keeping you awake or helping you to drift off, depending on the time of the day. It’s our circadian rhythm that keeps our body’s systems in check.

Your circadian rhythm is influenced by many outside factors such as your working hours, what exercise or physical activity you do during the day, and other lifestyle choices or habits, such as drinking alcohol or eating later in the day. Travelling and experiencing jet lag or working night shifts that go against the natural light and dark times of the day, can send our circadian rhythms out of sync. 

Resetting the circadian rhythm after disruption is possible:

  • Spending time outdoors in the light of the sun is the best way to boost your wakefulness and feel more alive in the daytime
  • Moving your body is also recommended as well as
  • Making sure your sleeping environment is comfortable in terms of temperature, lighting and your mattress is supportive
  • Avoiding blue light after dark is highly recommended, as well as caffeine, alcohol, nicotine, and late afternoon napping, as these can either keep you awake or impact the quality of your sleep.
  • Instead of using a screen as a way of switching off, try reading a book or meditating - something that doesn’t involve technology - this may help you fall asleep faster.

Why Is a Better Night’s Sleep So Important?

Because sleep helps our body and brain to slow down and recover, nearly every part of the body is affected by sleep and goes through change, which can impact us in many ways. Sleep has been linked to helping with concentration, productivity, and brain cognition. It can boost the immune system as the immune cells and proteins get rested to be able to fight off any incoming illnesses. 

Our hormones are working around the clock, and they tend to fluctuate during the different sleep stages. Quality of sleep also affects hormone production during our waking hours. It’s our circadian rhythm that helps to regulate the production of multiple hormones such as melatonin (promotes sleep), cortisol (stress response), leptin and ghrelin (hormones linked to appetite) -  which suggests that a better night’s sleep can help regulate appetite and stop overeating. Lack of sleep can also lead to an increase in cortisol, the stress hormone, which can lead to heart health problems. 

Generally, sleep affects your mood, so if you’re well rested, you will be in a better space with more energy. Sleep has also been shown to affect exercise performance and recovery, as well as improve memory… adding to the long list of reasons to prioritise getting a restorative night’s sleep.

How Can CBD Help You Sleep Better?

CBD works by slotting into our bodies’ endocannabinoid system (ECS) and regulating many of our essential functions, bringing them into homeostasis, or balance. These functions include the sleep-wake cycle, appetite, temperature, memory, and hormones as well as many more. 

Given that CBD taps into our ECS, which is responsible for keeping our hormones in balance, it’s no surprise that people often comment that they wake feeling more refreshed. It’s thought this is because CBD raises the level of anandamide in the brain - a naturally occurring cannabinoid found throughout the body. It helps to regulate other chemicals in the brain, including serotonin and dopamine. Both these neurotransmitters are crucial in improving mood and relaxation, as well as playing a part in our circadian rhythms, which help regulate our sleep-wake cycles, resulting in falling asleep faster.           

Neurologist Dr Mike Barnes adds:

"CBD has a very useful, positive benefit for sleep. It can improve not only getting off to sleep but also the duration and quality of the sleep. Many people will wake up much more refreshed" therefore many people use CBD sleep drops as a natural way of regulating their sleep patterns."  

Can CBD Help Insomnia?

Early research suggests CBD can help with several sleep disorders, such as insomnia, REM sleep behaviour disorder, and excessive daytime sleepiness disorder, as well as reducing anxiety and helping us to get better sleep.

Whilst it’s still preliminary research, people that have chronic pain are sleeping better with CBD, as well as those with anxiety. Research suggests that sleep improved in more than 65% of participants who used CBD to treat their anxiety, thought to be due to CBD’s calming effect on the nervous system. The same study also showed that almost 80% of participants who used CBD had lower anxiety levels within a month of using it.

There is also a study currently underway looking at the effects that CBD has on people who suffer from insomnia. Given that CBD can have a positive effect on reducing anxiety, there is hope that it will be of support to those suffering with anxiety-based insomnia to help break out of the cycle of this unrelenting sleep disorder. Further research like this will help us understand how CBD can help those with insomnia and help determine dosage and methods of using CBD for sleeplessness. 

Optimising Sleep Quality.

A lot of the ways of optimising sleep are taking us back to our ancestral ways of living, such as no artificial light after dark, and avoiding certain substances. Having a consistent routine that works with your body’s circadian rhythm, is the best way to ensure a better night’s sleep, and research supports the role of natural sleep aids such as CBD, for those who may be struggling to sleep well.

Are you in search of a better night’s sleep? Explore our Sleep collection now. 

And for more tips on how to hack your sleep, read our Guide to Getting Better in Bed.