It is widely known that stress can impact our health in the long run, so finding effective measures to alleviate stress and limit further health impacts is incredibly important. A study in 2018 highlighted the prevalence of stress in the UK, finding 74% of people felt so stressed at some point in the year that they struggled to cope. Making stress a common experience for our population. [1]

Cortisol, often dubbed the "stress hormone," is a crucial part of our body's response to stress, but its role extends far beyond that. Produced by the adrenal glands, cortisol helps regulate blood pressure and inflammation and supports our metabolism by regulating our blood sugar levels, playing an essential part in maintaining our overall health. 

Cortisol is vital for managing stress through the "fight or flight" response. When we face a stressor—be it physical or emotional—cortisol levels spike, alongside adrenaline and DHEA (a hormone used as a building block to make androgens and oestrogens). This release triggers a cascade of physiological changes that prepare the body to either confront or escape the threat. This response is crucial for survival, as it increases glucose availability, enhances brain function, and ensures that energy is diverted to essential processes. Its a significant component of the mechanism that supported us to hide or run from a big scary beast back in the day. 

However, cortisol's functions are not limited to stress management. In fact, its a big help in the mornings. Our cortisol levels typically follow a daily rhythm, with levels peaking in the morning to help us wake up  (the cortisol awakening response) before they gradually taper off throughout the day, allowing for our restful sleep at night. 

The Problem with Chronic Stress and Cortisol Resistance

While short bursts of cortisol are beneficial to help us function, chronic stress can keep the hypothalamic-pituitary-adrenal (HPA) axis perpetually activated - forming an almost constant state of fight or flight. 

This constant activation leads to persistently elevated cortisol levels, which disrupt the body's delicate feedback mechanisms over time, making it less sensitive to cortisol's effects—a condition known as cortisol resistance. As the body becomes increasingly resistant to cortisol, it requires higher levels of the hormone to achieve the same effects that were once triggered by lower amounts. Causing, a person's cortisol levels to rise overall.

Cortisol resistance is linked to a variety of health problems, including metabolic disorders, immune system dysfunction, and mental health issues such as anxiety and depression. Some of the symptoms of cortisol resistance include poor sleep, weight gain (particularly in the abdominal area), sugar cravings, and digestive issues. These symptoms underscore the importance of maintaining balanced cortisol levels.

Nutritional Approaches to Supporting Cortisol Balance

Managing cortisol effectively requires a comprehensive approach, and nutrition plays a significant role. Certain nutrients and supplements can support the body's ability to manage stress overall and also support cortisol regulation. 

Lemon Balm & Green Tea

Studies have shown that lemon balm consumed in foodstuffs daily (1.8g) reduces stress while also improving cognition and mood. The mechanism of these effects is predominantly unknown, but it is assumed that they occur due to a combination of plant extracts within the lemon balm. This coincides with other research findings that lemon balm's bioactive properties in supplement form have an overall ‘calming’ effect. [3]

In addition, lemon balm, combined with other herbal remedies such as Valeriana Officinalis, has been shown to be as effective for improving sleep as 0.125mg of Triazolam. [4] 

While much more research could be done to better understand the mechanisms behind lemon balm effects, it might be worth a try, especially in your evening snack.

Green tea has also shown its strength in reducing plasma cortisol levels by inhibiting cortisone reductase activity, limiting the conversion of cortisone to cortisol. [5] 

Green tea also holds the properties of L-theanine, an amino acid found in green tea leaves. L-theanine has been shown to have neuroprotective effects on the brain during exposure to acute stress. [6]

So, green tea might be worth a try next time you feel overwhelmed or as a midday drink to lower your cortisol after you’ve made the most of the cortisol awakening response in the morning.

L-Theanine

L-Theanine, is not just found in green tea, its found in highest quantiteas in albino yellow tea. The amino acid is well-known for its calming properties. It promotes relaxation without causing drowsiness, making it an excellent supplement for reducing stress. [6] 

L-Theanine works by physiologically reducing the effects of cortisol by reducing heart rate and blood pressure, increasing αlpha brain waves (associated with a relaxed state like that achieved in meditation) and also mildly enhancing levels of neurotransmitters in the brain such as serotonin and dopamine - helping to alleviate anxiety and promote a state of calm.

L-theanine is found in albino yellow tea, green, white, oolong and black teas. But it can also be bought in supplement form. 

Vitamin C

Vitamin C is more than just an antioxidant, in research high doses of vitamin C have been shown to increase the rate of cortisol recovery, reducing cortisol levels post-physiological stress. Other research has shown that administering high doses of vitamin C (1000-1500 mg) to athletes before they begin endurance sports reduces the increase in their cortisol levels. [7]

So if you think your high endurance sport is affecting your cortisol levels, vitamin C may be worth a try. 

B Vitamins

The stress mechanism depletes the B vitamins in your body since vitamins B6, B9, and B12 help reduce stress by supporting the activity of GABA, a chemical in your brain that calms the nervous system.

Vitamin B6 is particularly important because it helps convert an amino acid called glutamine into GABA. Higher GABA levels lead to lower cortisol levels. So, these B-vitamins help reduce stress by boosting GABA, which in turn keeps cortisol levels under control. [7]

Magnesium

Magnesium is involved in many biochemical reactions in the body, several of which are related to stress management. Magnesium not only plays a role in inhibiting cortisol production but also supports the production of GABA, a neurotransmitter that calms the nervous system. [7]  Stress has been shown to rapidly deplete magnesium levels. [8] 

Magnesium is particularly crucial in limiting cortisol and the stress response, so if you’re suffering from high levels of stress it could be worth considering if your magnesium intake is sufficient.

Vitamin D

Despite widespread claims by companies that low vitamin D levels can reduce cortisol, research findings on this topic are often contradictory, leading to controversy among scientists. 

Some studies suggest that vitamin D deficiency may contribute to cortisol overproduction, but the evidence remains particularly inconsistent across different research efforts. Investigations into vitamin D's potential role in endocrine disorders, including Type 1 and Type 2 diabetes, adrenal diseases, and PCOS, are still ongoing. [7]

Despite contradictory findings, adults in the UK are advised to take 10 µg/day of vitamin D from October to early March, so it may be worth trialling a vitamin D supplement if you don’t already anyway. [9]

Lifestyle Strategies to Support Healthy Cortisol Levels

In addition to nutritional support, certain lifestyle modifications are essential for maintaining healthy cortisol levels and reducing the risk of cortisol resistance.

Light to Moderate Exercise: Engaging in regular, light to moderate physical activity such as casual walking, yoga and other gentle physical activity is beneficial generally. But this type of exercise has been shown to reduce cortisol levels, whilst also increasing overall sleep quality and increasing the duration of REM sleep. 

A meta-analysis into the effect of twelve-week programmes of yoga-asana and mindfulness based practice found strong evidence that the moderate level of activity reduced resting heart rate and fasting blood glucose levels. While also reducing cholesterol levels, low-density lipoprotein levels, and blood pressure. [10]

Prioritising Sleep: Sleep is crucial for cortisol regulation. The amount of REM (rapid eye movement) sleep in ‘healthy normal sleepers’ per night has been demonstrated to positively correlate to 24-hour urinary-free cortisol levels. [11] So the greater the opportunity for REM sleep, the better. Deep sleep (slow wave sleep) has also been associated to reductions in plasma cortisol levels. [12]

Prioritizing sleep by establishing a consistent bedtime routine and creating a relaxing sleep environment could support you to significantly improve your cortisol balance.

Reducing Caffeine Intake: Caffeine is a central nervous system stimulant, that contributes to the stress axis by elevating glucocorticoids such as cortisol and its precursors, catecholamines such as adrenaline, noradrenaline and dopamine which in combination contribute to the magnitude and duration of the stress response. [13]

Swapping out high-caffeine drinks such as coffee and some energy drinks with hot drinks such as green tea that have demonstrated effects for reducing stress hormones could help reduce your stress levels overall. [14]

Conclusion

Cortisol plays a vital role in our health, but when its levels become imbalanced due to chronic stress, it can lead to significant health challenges. By understanding the role of cortisol in the body and implementing strategies to manage stress, we can support our health and well-being.

Including foods and drinks or taking nutritional supplements containing L-Theanine, Vitamin C, B Vitamins, and Magnesium, along with lifestyle changes like regular exercise, sufficient sleep, and stress management techniques, can all contribute to balanced cortisol levels. By taking proactive steps to manage cortisol, we can protect our health from the damaging effects of chronic stress.