What is the circadian rhythm?
Circadian rhythm is another name for your body’s internal clock that regulates a variety of biological processes and essential functions - repeating (roughly) every 24 hours. The circadian clock is present in cells throughout our entire body. It can impact hormone production, detoxification, energy metabolism, cell regeneration, brain wave activity, body temperature, sleep-wake cycle (a well-known example of the importance of circadian rhythms), and so much more.
In humans, the rhythms are centrally controlled by the so called “master clock”, located in the hypothalamus. This master clock is directly influenced by environmental cues, predominantly light, which is why circadian rhythms are tied to the cycle of day and night. While other cues, like exercise, social activity, and temperature, can affect the master clock, light remains the most powerful influence on circadian rhythms.
During the day, light exposure causes the master clock to send signals that generate alertness to help keep you awake and active. As night falls, it initiates the production of melatonin (the sleep promoting hormone), then keeps transmitting signals that help you stay asleep through the night. In this way, your circadian rhythm creates a stable cycle of restorative rest. If your circadian rhythm is dysregulated, important activities such as DNA repair may not occur on the right schedule or even may not occur at all. For example, cell division, needed for repair of gut lining, occurs at night.
Disruption to normal circadian rhythms can create significant health problems. Acute short-term impacts include: impulsivity, memory impairment, loss of attention, mood instability, reduced cognition and an impact on creativity and the ability to process information. Chronic long-term disorders include: depression, anxiety, gut health issues, sleep-wake disorders, cardiovascular disease, immune suppression, cancer, metabolic syndrome and Type 2 Diabetes.
What affects the circadian rhythm?
Changes in your body and environmental factors can cause your circadian rhythms to be out of sync. Light from electronic devices at night can confuse our biological clocks, jet lag or shift work causes changes in the light-dark cycle, mutations or changes in certain genes can affect our biological clocks. Some of these you cannot change: like your age, family history, or gender. Others you can manage: like your lifestyle or occupation.
-
Age: the rhythm and timing of your sleep-wake cycle can change with age. Teens may naturally have a later bedtime while older adults usually go to sleep and wake up early.
-
Family history or genetics: your genetic preference of an early/late bedtime can raise your risk for advanced or delayed sleep-wake phase disorder if your rhythm is out of sync with your environment or social responsibilities.
-
Gender: men are more likely to have advanced sleep-wake phase disorder than women. But women may be at higher risk at certain stages of life. Hormonal changes that happen during pregnancy, after childbirth, and at menopause can cause problems with sleep. Discomfort during pregnancy may also prevent good-quality sleep. After childbirth, sleep interruptions and nighttime exposure to light while caring for a newborn can increase your risk for circadian rhythm disorders.
- Environment or occupation: people who work during the night have a higher risk for shift work disorder. Jet lag disorder is more common in pilots, flight attendants, athletes, and people who travel often for business.
- Lifestyle habits: alcohol and chronic caffeine overuse, illegal drug use, lack of exposure to natural light during the day, unhealthy sleep habits (such as regularly staying up late and being exposed to artificial light)
- Medical conditions: several medical conditions can increase your risk for circadian rhythm disorders, including: autism spectrum disorders, certain genetic conditions, conditions that affect eyesight or cause damage to the brain, mental health conditions, neurodegenerative diseases (such as Alzheimer’s and Parkinson’s disease, dementia).
How to reset your circadian rhythm?
- Get into a routine
While we don’t have full control over our circadian rhythm, there are tips that can be taken to try to better entrain our sleep cycles.
- Keep a regular meal schedule, especially if you are a shift worker or sleep at irregular times.
- Not having a consistent sleeping schedule can really mess with your sleep. Wake up and go to sleep at the same time every day. Even if you are unable to fall asleep at your desired time, make sure to set an alarm and wake up at the set time anyway. This will keep you on track. Avoid daytime naps, especially in the afternoon. However, shift workers may benefit from a short nap before the start of their shift.
- Read a book before bed, take a warm shower, put the phone away. Make your room completely dark, keep it cool.
- Spend some time outdoors, especially efficient if you do it first thing in the morning – will further enhance the circadian resetting effect.
- Eat adequate calories. You need to be well fuelled to sleep well. Balance your blood sugars during the day by eating complete meals (include protein, carbs and fat).
Avoid blue lights in the evening
Using screen-based electronics for work, entertainment, communication, education is an integral part of our lives. But there are downsides. Blue light is the most important regulator of our sleep-wake cycle. Exposure during the day from sunlight is a healthy promoter of energy and concentration. However, artificial blue light spectrum mimics the sun - without providing any of the benefits. Using devices in the evening and nighttime disrupts our natural sleep-wake cycle by tricking the brain into not producing melatonin before bed. This causes us to feel less sleepy than we should.
There are a number of steps you can take to reduce exposure to blue light:
- Establish a nightly schedule that involves ceasing the use of electronics at least 1 hour before bedtime.
- Storing phones and other devices outside of the bedroom can have a big impact on nighttime blue light exposure.
- Use special glasses that filter out blue light or blue light-filtering apps to shift the color tone of a tablet or smartphone screen toward warmer wavelengths of the light spectrum.
- Alter settings: many electronic devices include options for “night mode” or “dark mode” that change the screen background to black, reducing blue light exposure.
- Red light exposure does not suppress melatonin production, so it could help to use red (orange or yellow) light bulbs for evening reading lamps and nightlights.
- Ensure exposure to bright light during the day helps to synchronize circadian rhythms and promotes sleepiness at bedtime.
Exercise and the circadian rhythm
Exercise and sleep share a somewhat symbiotic relationship. Proper exercise can improve sleep quality and duration, while a healthy sleep-wake cycle ensures more strength and endurance when you work out. However, exercise might also feel stimulating if you do it too close to bedtime. This is very individual, but might need to avoid working out within 1-2 hours of your bedtime. Overtraining without adequate recovery is also not a good idea.
Adding vitamin C on the other hand, might be especially beneficial to those who train regularly. It’s important for connective tissue repair and as an antioxidant, may help to reverse some of the oxidative damage that may occur from exercise. Moreover, vitamin C promotes a healthy immune system and may help to prevent the dip in immune function that may occur right after exercise.
Consider reducing caffeine and alcohol consumption for improving circadian rhythm
As a short-term energy booster, caffeine can be a very effective – albeit, temporary – fix for anyone who experience grogginess or needs some energy boost. Caffeine also has a half-life of 5 hours in a healthy adult, meaning it takes an average of 5 hours for the body to eliminate half the amount of consumed caffeine. For best results, consume a moderate amount of caffeine for the first few hours when you’re awake, but stop consuming it at least 5-7 hours before bed.
Caffeine has been proven to be powerful enough to shift a person’s internal clock, therefore it could be the reason why certain people struggle to get up the next day. Even if you can easily fall asleep after a cup of coffee, your internal clocks have still been altered.
Alcohol is a central nervous system depressant that induces feelings of sleepiness after it is consumed, so many people consume it in order to feel more relaxed before bed. However, it also lowers sleep quality and duration, making sleep unrestorative and choppy.
Support your nervous system with nutrients for circadian rhythm
Following a balanced diet as part of a healthy lifestyle can improve brain function, reduce the risk of many serious conditions, and manage neurological symptoms. For nervous system health, it is recommended to consume foods rich in antioxidants, potassium, magnesium, B-vitamins, and of course – essential fatty acids.
DHA and EPA essential fatty acids - commonly found in oily fish - appear to be most useful for the nervous system and have strong anti-inflammatory properties. DHA is the main omega-3 fat in your brain, retina and nervous system in general. Getting adequate amounts is also associated with a reduced risk of depression. The body cannot make these nutrients from scratch. It gets them by metabolizing their precursor, α-linolenic acid (LNA), or from foods or dietary supplements containing the fatty acids in a readily usable form. Zooki’s omega-3 supplement provides both EPA & DHA fatty acids, it’s delicious (no fishy taste!) and in bioavailable form. As an added bonus, it will also improve your overall immune system (contains vitamin D).
Our bodies require antioxidants to keep free radicals in check. When there are more free radicals than antioxidants, oxidative stress occurs. This can negatively affect your nervous system. In terms of mental health and cognitive ability, the benefits of vitamin C are endless. It plays an integral role in brain and nerve cell development and myelin production - all necessary for the protection of the nervous system. According to Alison Smith Ph.D., vitamin C helps convert dopamine into norepinephrine - which is essential for focus, memory performance and emotional calm. Zooki’s liposomal vitamin C sachet is a convenient mess-free way to ensure daily cognitive support.
Conclusion
When circadian rhythm is thrown off, it means that the body’s systems don’t function optimally. Given the essential role of sleep for productivity and overall health, there are often significant consequences when a person’s circadian rhythm is off. You may have noticed that you are more likely to get sick when very tired or otherwise feeling out-of-sync. Many people who travel have noted that they are most likely to become ill just after a large trip, especially one that takes them across time zones and causes the dreaded jet lag. Is this a coincidence? Studies have long suggested a link between the circadian clock and the immune system.
Try this: 20 minutes of indirect sun in your eyes in the morning, 20 minutes on your body later during the day and 10 minutes indirect light in your eyes around sunset – an amazing way to support your body in regulating estrogen, testosterone, cortisol and improving sleep quality.
If you experience insomnia, daytime sleepiness, difficulty waking up, depression, or sleep loss, talk to your healthcare provider who can best diagnose the cause and offer the most appropriate treatment.
The most important action to take is to ensure you take care to keep your circadian rhythms functional. Stay consistent, consistency is key.
References
What Is Circadian Rhythm? | Sleep Foundation - Circadian Rhythm. What it is, what shapes it, and why it’s fundamental to getting quality sleep
Circadian Rhythm Disorders - Causes and Risk Factors | NHLBI, NIH - CIRCADIAN RHYTHM DISORDERS: Causes and Risk Factors
Circadian Rhythms | Circadian Therapeutics - What happens when circadian rhythms are disrupted?
Circadian Rhythm Disorders - Treatment | NHLBI, NIH - CIRCADIAN RHYTHM DISORDERS: Treatment
Can You Change Your Circadian Rhythm? | Sleep Foundation - Can You Change Your Circadian Rhythm?
How Does Blue Light Affect Children's Sleep? | Sleep Foundation - How Blue Light Affects Kids’ Sleep?
https://chronoceuticals.com/discovered-a-direct-link-between-circadian-clock-and-the-immune-system/ - DISCOVERED: A DIRECT LINK BETWEEN CIRCADIAN CLOCK AND THE IMMUNE SYSTEM
Omega-3 Linked to Better Nervous-System Function (rejuvenation-science.com) - Omega-3 Linked to Better Nervous-System Function
Vitamin C For Anxiety, Focus, Mood & Depression ✔️ NC (naturalcalm.ca) - Mental Health: Vitamin C for Anxiety, Depression, Memory and Calm