How to optimise your cortisol awakening response

By Mark Payne (Functional Medicine Practitioner)

I'm feeling blue, blue light that is. As I sit here, early morning, in my back garden, sipping my cup of tea soon after I have woken, I know that my body is busy powering me up, and getting me ready for the day ahead, and it all starts with this little thing called cortisol.

So what is cortisol and why is it so important? This article will delve into the topic of all things cortisol, why it is good, what can go wrong, and most importantly what you can do about it to optimise your health.

Cortisol, often called the "stress hormone," is produced by the adrenal glands and plays a crucial role in various body functions. It helps regulate metabolism, inflammation, blood sugar levels, and the body's sleep-wake cycle, among other things. 

Cortisol levels naturally fluctuate throughout the day in a pattern known as the diurnal rhythm or cortisol cycle. Typically, cortisol levels peak in the early morning, helping to promote alertness and energy, and gradually decline throughout the day, reaching their lowest point at night to support restful sleep.

This natural cycle is essential for your well-being, but modern lifestyles can disrupt it, leading to health issues such as sleep disorders, weight gain, increased anxiety and depression, immune suppression, hormonal imbalances, and heightened cardiovascular risk due to persistently high cortisol levels.

By understanding the cortisol awakening response you can implement strategies to optimise cortisol levels and enhance your daily functioning.

Understanding the diurnal rhythm and the cortisol awakening response

The diurnal rhythm of cortisol refers to the natural, day-night cycle or circadian rhythm that dictates the timing and amount of cortisol release in the body.

Cortisol levels are not constant throughout the day; instead, they fluctuate in a predictable pattern that is influenced by our sleep-wake cycle, among other factors.

Diurnal rhythm of cortisol

1. Morning peak: Cortisol levels are highest in the early morning, usually around 30 minutes after waking. This surge is known as the cortisol awakening response. It helps to promote alertness and mobilises energy resources to prepare the body for the day's activities.
2. Daytime decline: After reaching its peak, cortisol levels gradually decline throughout the day. This decline is part of the normal rhythm and is associated with decreasing alertness and preparing the body for rest.
3. Evening and night: Cortisol levels are lowest at midnight and during the early part of sleep. This allows the body to relax and recover from the day's activities.

Cortisol Awakening Response (CAR)

The cortisol awakening response is particularly significant for several reasons:

1. Energy mobilisation: It ensures that energy is readily available upon waking, which is essential for starting the day
2. Psychological preparation: The CAR is believed to prepare the body and mind for the anticipated demands of the day, enhancing alertness and cognitive performance
3. Indicator of health and stress levels: Abnormalities in the CAR, such as a blunted or exaggerated response, can indicate stress-related disorders or other health issues. For example, a blunted CAR may be associated with chronic stress, depression, or PTSD, while an exaggerated CAR might indicate anxiety disorders or excessive stress
4. Immune system regulation: The morning increase in cortisol can help regulate the immune system by preventing excessive inflammation

The relationship between cortisol, inflammation, and glucose regulation

Cortisol, a glucocorticoid hormone from the adrenal glands, plays a pivotal role in managing stress, inflammation, and glucose regulation. It offers anti-inflammatory benefits by suppressing pro-inflammatory cytokines and enhancing anti-inflammatory ones, crucial for preventing immune overreaction. However, chronic stress can induce cortisol resistance, akin to insulin resistance, diminishing its anti-inflammatory capacity and potentially leading to persistent low-grade inflammation - a precursor to various chronic conditions.

In terms of glucose metabolism, cortisol boosts blood glucose levels by stimulating gluconeogenesis, ensuring energy availability during stress or fasting. Yet, its impact on reducing insulin sensitivity can complicate glucose uptake by cells, potentially elevating blood sugar levels and increasing the risk of type 2 diabetes over time.

The relationship between cortisol, inflammation, and glucose balance is essential for bodily homeostasis but can signal disease pathways if dysregulated. Persistently high cortisol from chronic stress may cause ongoing inflammation and disrupted glucose control, elevating the risk of metabolic syndrome, cardiovascular disease, and type 2 diabetes. Addressing these risks involves lifestyle changes, including regular exercise, effective stress management, and a balanced diet, to modulate cortisol levels, mitigate inflammation, and enhance glucose regulation.

Strategies to optimise the CAR and cortisol levels

Optimising the cortisol awakening response and overall cortisol levels involves lifestyle and environmental adjustments that promote a healthy circadian rhythm and stress management. 

These strategies can help enhance alertness in the morning, improve stress resilience, and support overall health by maintaining balanced cortisol secretion throughout the day.

Morning Light Exposure

• Natural light: Aim to get exposure to natural sunlight as soon as possible after waking up. Morning light exposure can significantly enhance the CAR, helping to increase cortisol levels naturally upon waking, which boosts alertness and mood
• Light therapy: For individuals who wake up before dawn or live in regions with limited natural light during certain seasons, light therapy boxes can mimic natural sunlight, helping to stimulate the CAR

Blue light blocking glasses

• Blue light blockers: In addition to natural light exposure in the morning and minimising screen time at night, using specialised eyewear such as blue light blocking glasses can be an effective strategy. These glasses are designed to reduce exposure to artificial blue light in the evening. By filtering out this type of blue light, which is known to disrupt our natural sleep-wake cycles and raise our cortisol levels - which is less than ideal at bedtime - these glasses can help maintain a healthier balance, aiding in falling asleep, better sleep quality and optimising the cortisol awakening response. Integrating such eyewear into your evening routine can be a practical step towards enhancing overall well-being

Consistent sleep schedule

• Regular bedtime and wake time: Maintaining a consistent sleep schedule, even on weekends, helps regulate the body's internal clock and supports the natural rhythm of cortisol secretion
• Sleep hygiene: Create a bedtime routine that promotes relaxation, such as reading or meditation, and ensure the sleep environment is conducive to rest (e.g., cool, dark, and quiet)

Stress management

• Mindfulness and relaxation techniques: Practices such as meditation, yoga, and deep breathing exercises can help reduce stress and may normalise cortisol patterns
• Physical activity: Regular exercise, especially in the morning, can positively affect cortisol levels and enhance the CAR. However, it's important to balance activity levels, as excessive exercise without adequate recovery can increase cortisol levels which can disrupt its natural rhythm and contribute to inflammation

Diet and nutrition

• Balanced diet: A diet rich in whole foods, fruits, vegetables, lean proteins, and whole grains can support overall hormonal balance, including cortisol
• Timing of meals: Eating at regular intervals can help maintain stable blood sugar levels, indirectly supporting healthy cortisol patterns. Some evidence suggests that consuming a good quality breakfast might influence the CAR positively

Limiting caffeine and alcohol

• Caffeine consumption: Avoid caffeine for at least 1 hour after waking, and limit or avoid caffeine intake in the late afternoon or evening, as it can affect sleep quality and subsequent cortisol regulation.
• Alcohol moderation: While moderate alcohol consumption might not significantly disrupt cortisol in the short term, excessive intake can interfere with sleep and stress regulation, affecting cortisol patterns.

Digital detox before bed

• Reducing screen time: Limit exposure to blue light from screens before bedtime to improve sleep quality and support the natural decline of cortisol in the evening.

Implementing these strategies can help regulate the CAR and overall cortisol levels, contributing to improved stress management, better sleep quality, and enhanced daily well-being. 

Given individual differences in physiology and lifestyle, some strategies may be more effective for certain individuals than others. Experimenting with various approaches and observing their impact on your well-being can help identify the most beneficial practices.

Mark Payne is a functional medicine practitioner at Melbourne Functional Medicine.  A clinic dedicated to personalised healthcare and longevity services.  Find out how the team at Melbourne Functional Medicine can help you find the healthiest version of you.