Regulating your circadian rhythm (and why it’s important)
In your quest for better health, or your constant resolve to achieve more restful sleep, you may have come across the term circadian rhythms. Our circadian rhythms are a built-in part of our physiology, modified by cues from our environment including temperature and light.
These rhythms provide signals for our bodies to generate the hormones that tell us when to wake, sleep, eat and be active. By understanding the role of these hormones, you can unlock the key to keeping your body in tune.
How do hormones help you through the day?
Humans are programmed to live by a diurnal rhythm, which simply means we are awake during the light phase and asleep during the dark phase. This differs from nocturnal species, such as possums, who are awake during the dark phase and sleep during the day. Within our hypothalamus resides the central clock of our biological rhythms, the suprachiasmatic nucleus (SCN) and local clocks are present in our organs and tissues. The SCN receives light information through our retinas. It transfers this information via neural networks in our brain to other organs to regulate the expression of other genes across the circadian rhythm. These gene changes can control the production and release of some hormones that regulate our metabolism, digestion, our attention and alertness and our immune system.
Cortisol could be described as our body’s built-in alarm clock. It rises early in the morning, reaching a peak around 8am, and falls throughout the day. Cortisol gets our body going by increasing our heart rate and blood pressure, as well as activating our metabolism and our immune system. Cortisol is released from our adrenal glands, but the trigger for cortisol release starts in the brain.
Melatonin is produced by the pineal gland in our brain and follows an almost opposite pattern of release to cortisol. As the light entering the SCN decreases later in the day, melatonin production is increased. Thus melatonin is always highest during the dark phase, and lowest during the light phase. Melatonin not only helps regulate our sleeping and waking patterns, it’s also reported to be a powerful antioxidant. If we don’t get enough of it, we can have trouble sleeping. Melatonin production decreases noticeably during menopause. This explains in part why sleeplessness is one of the more common symptoms during menopause. Establishing a regular bedtime and morning routine can help to alleviate these symptoms.
Light and dark
Trick of the light
To work with your circadian rhythms, synchronise your light exposure with the movement of the sun. Start by waking with the sun and aim to get as much natural light as possible throughout the day. As the sun sets, use dim lamps or candles to illuminate your home and avoid sources of bright light. Reduce time spent with screens or devices that shine blue light directly into your eyes. It is recommended that we go to bed no more than three hours after sunset and rise with the sun. Traditional Chinese and Ayurvedic medicine practices encourage seasonal adjustments of activities to synchronise with the varying lengths of day and night as the seasons change.
New parents can help their babies find their own circadian rhythms by exposing them to the light and keeping most activities to the daylight hours. Leave curtains open during daytime sleeps, and avoid light and noise in the lead-up to bedtime and during the night.
Tossing and turning?
Relax your senses by filling your room with a sleep-inducing scent just before bedtime. Try using endota’s Essential Oil Diffuser with a Calm Essential Oil mix of Ylang Ylang, Bergamot and Lavender.
Disruption to our circadian rhythms can negatively affect our health. Shift workers, for example, have higher rates of Type 2 diabetes than normal. It’s believed that this is because the times when they are active, eating and sleeping are not in sync with their circadian rhythms.
You don’t have to be a shift worker to disrupt your circadian rhythms. Termed ‘social jetlag’, late nights and poor sleep may also result in circadian rhythm misalignment. This in turn is associated with obesity and has behavioural ramifications including increased alcohol consumption and smoking.
Simply matching what we eat to the time of day can have substantial health benefits. Altering the timing of meals in shift workers may be a useful strategy to mitigate some of the negative health consequences of this type of work. Earlier meal times, or breakfasts that are more calorie dense than dinners, are associated with more effective weight loss in overweight and obese people.
Late night tummy grumbles?
Try peppermint tea to soothe the stomach and satisfy the palate, such as endota’s Organic Peppermint Loose Leaf Tea Bags.
Products to help you achieve a better sleep
Dr Hayley Dickinson is a research scientist with a PhD in women’s reproductive health, who does not claim to be a medical practitioner. We seek to offer insights into the health of women experiencing the reproductive, menstrual and hormonal characteristics of female biology. In addition, we offer scientific insight into wellness and lifestyle choices relevant to all. Neither endota nor Dr Hayley Dickinson accept any liability for the information or advice (or use of such information or advice) which is provided in this blog or incorporated into it by reference. We provide this information on the understanding that all persons accessing it take responsibility for evaluating its relevance and accuracy. Women are encouraged to discuss their health needs with a health practitioner. If you have concerns about your health, you should seek advice from your health care provider or if you require urgent care you should go to the nearest hospital Emergency Department. © endota, September 2018
• Mohawk JA,Green CB, Takahashi JS (2012) Central and peripheral circadian clocks inn mammals. Annu Rev Neurosci. 35: 445-462 https:// www.ncbi.nlm.nih.gov/pubmed/22483041
• Pan A, Schernhammer ES, Sun Q, Hu FB (2011) Rotating Night Shift Work and Risk of Type 2 Diabetes: Two Prospective Cohort Studies in Women. PLoS Med 8(12): e1001141 https://journals.plos.org/ plosmedicine/article?id=10.1371/journal.pmed.1001141
• Potter GDM, Skene DJ, Arendt J, Cade JE, Grant PJ, Hardie LJ (2016) Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences, and Countermeasures. https://www.ncbi.nlm.nih.gov/ pubmed/27763782
• Potter GDM, Cade JE, Grant PJ, Hardie LJ (2016) Nutrition and the Circadian System. Br J Nutr 116(3): 434-442 https://www.ncbi.nlm.nih. gov/pubmed/27221157
• Jakubowicz D, Barnea M, Wainstein J, Froy, O (2013) High caloric intake at breakfast vs. dinner differentially influences weight loss of overweight and obese women. Obesity (silver Spring) 21(12): 2504-12 https://www. ncbi.nlm.nih.gov/pubmed/23512957
• Garaulet M, Gomez-Abellan P, Alburquerque-Bejar JJ, Lee YC, Ordovas JM, Scheer FA (2013) Timing of food intake predicts weight loss effectiveness. Int J Obes (Lond) 37(4): 604-11 https://www.ncbi.nlm.nih. gov/pubmed/23357955