Is Stress Linked To Our Sleep-Wake Cycle?

Here at Healthpath, we’re proud to offer evidence-based advice. However, we’re aware that science can seem a bit impenetrable and dry. Boring, even.

We also believe that education is the first step to regain control. We read a lot of scientific papers, so we thought it would be a good idea to create a digest (no pun intended) of some of the key research.

We hope these plain-English versions bring the science to life and—even more importantly—help you address your symptoms for good.


“The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids”

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What’s the title in plain English?

How stress might be linked to our sleep-wake cycle

What did they do?

In humans, a master clock in the brain coordinates our 24-hour circadian rhythm. This regulates our sleep-wake cycle.


This paper looks at evidence that a similar circadian clock genes exist in the adrenal glands, suggesting that cortisol—the main hormone released from our adrenal glands—is a major synchronizer of the circadian system. This has a knock-on effect on important metabolic processes in the body.


What are the take-home points from the study?

1. Under normal conditions, the 24-hour cortisol rhythm shows an early morning maximum and then declines throughout the day. Minimal cortisol levels are reached in the evening and early part of the night. It’s now recognised that a wide variation in circulating cortisol levels exist from one person to the next.

2. Circadian dysregulation may occur when our adrenal ‘clock genes’ are triggered at different times of the day in response to changes in our environment. This may cause dysregulation of both cortisol and melatonin, which are stated as being the main controllers of central circadian control.

3. Factors that influence the circadian rhythm and our normal sleep-wake cycle include the light-dark cycle, the timing of food intake and perceived physical and emotional stress.


The Healthpath view

This study presents evidence that adrenal function has important implications for health and disease prevention. Adrenal function can be reliably measured in saliva.

If you’re trying to maintain a healthy sleep-wake cycle, addressing adrenal function may be something to consider with tailored nutrition and lifestyle advice.

Read the full published study here.

Tegan Philp BA PgDip MSc is a Registered Nutritional Therapist. Passionate about all things gut-related, her master’s dissertation was on the role of the microbiome in cardiovascular outcomes. Tegan has over eight years’ experience working for leading nutrition colleges in both Australia and the UK. You can learn more about Tegan on her practitioner page or connect with her via LinkedIn.

Ref: Oster, H., Challet, E., Ott, V., Arvat, E., de Kloet, E. R., Dijk, D. J., Lightman, S., Vgontzas, A., … Van Cauter, E. 2016. The Functional and Clinical Significance of the 24-Hour Rhythm of Circulating Glucocorticoids. Endocrine reviews, 38(1), 3-45.

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