Cortisol is a steroid hormone produced by the adrenal glands, which sit above each kidney. It belongs to the glucocorticoid family and is released into the bloodstream in response to stress signals and low blood glucose levels. Cortisol production is regulated by the hypothalamic-pituitary-adrenal (HPA) axis, and its levels vary throughout the day, usually being higher in the morning and lower in the evening, a cycle known as the circadian rhythm.
What is the role of cortisol?
Cortisol plays an important part in the normal functioning of the body and is essential for metabolism. It helps maintain blood glucose levels by mobilising energy reserves, which is vital for fuelling the body during periods of stress or intense physical activity.
Cortisol also regulates the balance of fluids and salts in the body, influencing blood pressure and blood volume.
It acts as a natural anti-inflammatory agent, helping to control the immune system's response, reducing inflammation and preventing the overactivity that can cause autoimmune or allergic problems.
In addition, cortisol is involved in cognitive and memory processes, influencing the ability to concentrate and mental adaptability.
The role of cortisol in the fight-or-flight response
One of the most critical roles of cortisol is its involvement in the fight or flight response. When a person faces a threat or acute stress, the hypothalamus in the brain triggers the release of corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH in turn signals the adrenal glands to release cortisol into the bloodstream. The purpose of this rise in cortisol is to prepare the body to react quickly and effectively to stress: it stimulates the breakdown of glycogen into glucose to provide quick energy, raises blood pressure and helps redirect blood towards the skeletal muscles and the brain, which are essential for fast physical and mental reactions.
In addition, cortisol limits functions that are not essential in emergency situations, such as digestion, reproduction and growth, allowing the body to focus entirely on handling the immediate stress. Cortisol therefore plays a vital part in the body's ability to cope with stress and imminent danger.
The influence of the stress hormone on health
The complications of high cortisol levels
High cortisol levels over the long term can have negative effects on health, contributing to various conditions. Chronic stress can lead to a constant secretion of cortisol, which can cause problems such as high blood pressure, weight gain (especially around the abdomen) and an increased risk of type 2 diabetes. This hormone raises blood glucose by stimulating hepatic gluconeogenesis (the production of glucose by the liver) and by reducing the use of glucose by the muscles and other tissues.
Under chronic stress, constantly high cortisol levels expose the body to glucose for prolonged periods, which can cause cells to become resistant to insulin, the hormone responsible for transporting glucose from the blood into the cells. This insulin resistance forces the pancreas to produce more insulin in order to keep blood sugar at a normal level. Over time, this process can exhaust the pancreatic beta cells that produce insulin, contributing to the onset of type 2 diabetes.
In addition, high cortisol levels are associated with psychological conditions such as anxiety and depression, because the hormone can influence brain chemistry and emotional responses.
Excess cortisol can affect the immune system, making the body more susceptible to infections and illness. It can also cause sleep disturbances, since high cortisol levels can disrupt the natural sleep cycles. In severe cases, abnormally high cortisol levels can lead to Cushing's syndrome, a rare but serious condition that shows itself through weight gain, fatigue, high blood pressure and skin changes.
The complications of low cortisol levels
The complications associated with low cortisol, a condition known as adrenal insufficiency or Addison's disease, are rarer than those caused by high cortisol levels. Adrenal insufficiency leads to symptoms such as extreme fatigue, muscle weakness, weight loss, low blood pressure and hyperpigmentation of the skin. Low cortisol levels can also compromise the body's ability to cope with physical or emotional stress, triggering Addisonian crises, which are medical emergencies requiring immediate treatment.
Electrolyte imbalances, such as low sodium and high potassium levels, are common and can lead to dehydration and cardiac arrhythmias. Because of insufficient cortisol production, the immune system can become overactive, which increases the risk of autoimmune disease. In general, adrenal insufficiency and low cortisol levels are far less common than hypercortisolism, but they can have a significant impact on health if they are not treated properly.
Tests for measuring cortisol levels
Several types of test can be carried out to assess cortisol levels. The cortisol blood test is the most common and measures the level of the hormone in the bloodstream, usually in the morning, when cortisol should be at its peak.
Other methods include 24-hour urine tests, which measure the total amount of cortisol excreted in the urine over the course of a day, and saliva tests, which can assess cortisol levels at different times of day in order to check the hormone's circadian rhythm.
These tests can help diagnose problems linked to cortisol overproduction or insufficiency, providing essential information for appropriate treatment. In a healthy body, normal cortisol levels range between 6 and 23 micrograms per decilitre (mcg/dL) in the morning and fall to around 3 to 13 mcg/dL in the evening.
How quickly is cortisol released in the body?
Cortisol is released in the body according to the circadian rhythm, with a peak in the early morning, right after waking, and low levels during the evening and night. Once secreted, cortisol has a half-life of around 60 to 90 minutes, which means that its levels drop by half about one to one and a half hours after release. However, the time needed to clear cortisol completely from the body can vary depending on individual factors such as metabolism, state of health and level of physical activity.
Under normal conditions, cortisol is metabolised and eliminated through the liver and kidneys. In cases of acute or chronic stress, the adrenal glands may keep releasing cortisol, holding levels high for longer, which can make it harder for the body to clear it quickly.
Ways to lower cortisol levels in the body
- Relaxation techniques:
- Meditation and mindfulness - these can help reduce stress and, with it, cortisol levels.
- Deep breathing and the therapeutic heart-brain coherence technique - these help calm the nervous system and lower cortisol levels.
- Regular physical exercise:
- Moderate physical activity such as walking, jogging or swimming can lower cortisol levels and improve general well-being.
- Quality sleep:
- Making sure you get enough restful sleep can help regulate cortisol levels.
- A healthy diet:
- Eating foods rich in antioxidants, vitamins and minerals, such as vegetables, fruit and wholegrain cereals, can help reduce oxidative stress and cortisol levels.
- Socialising and emotional support:
- Spending time with friends and family and receiving emotional support can help reduce stress.
- Limiting caffeine and alcohol:
- Cutting down on caffeine and alcohol can help keep cortisol levels low.
- Time management:
- Organising your time effectively and avoiding overload can reduce stress and cortisol.
- Supplements and adaptogenic herbs:
- Herbs such as ashwagandha, rhodiola and ginseng are known for their ability to reduce stress and balance cortisol levels.
Are there medicines that lower cortisol levels?
Yes, there are medicines that can lower cortisol levels in the body; they are used mainly to treat conditions such as Cushing's syndrome, which is characterised by cortisol overproduction. These medicines work through different mechanisms: some inhibit the enzymes essential for cortisol synthesis in the adrenal glands, while others block cortisol receptors, preventing the hormone from binding to tissues and exerting its effects.
Certain medicines can also reduce cortisol production by affecting the function of the adrenal glands. It is important that the use of these medicines is managed by a specialist, since inadequate control of cortisol levels can lead to adverse effects and health complications.
The benefits of neurofeedback in balancing cortisol levels in the body
- Reducing stress:
- Neurofeedback can help reduce stress by regulating brainwaves and promoting emotional balance.
- Improving sleep:
- By training the brain to work in more relaxed rhythms, neurofeedback therapy can contribute to more restful sleep and to lower cortisol levels.
- Emotional regulation:
- Neurofeedback can improve the capacity for emotional regulation, which can lead to a healthier response to stress and to lower cortisol levels.
- Improving cognitive function:
- By optimising the way the brain works, neurofeedback can improve memory, concentration and mental clarity, thereby reducing the negative effects of cortisol on cognition.
- Improving mental health:
- Neurofeedback is a useful tool in the treatment of anxiety and depression, helping to reduce symptoms and to balance cortisol levels.
- Building resilience to stress:
- By training the brain to cope with stress more effectively, neurofeedback can increase the body's resilience to stressors, thereby reducing their impact on cortisol levels.
If you want to prevent the negative effects of cortisol in a non-invasive way that also brings you benefits on many other levels, discover neurofeedback therapy. Book a consultation with a specialist now and begin the journey towards a balanced body.
References:
- Gadea, M., Aliño, M., Hidalgo, V., Espert, R. and Salvador, A. (2020). Effects of a single session of SMR neurofeedback training on anxiety and cortisol levels. Neurophysiologie Clinique, [online] 50(3), pp.167–173. doi:https://doi.org/10.1016/j.neucli.2020.03.001.
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