Cortisol, also known as the “stress hormone” has many important functions in the body and is constantly released in small amounts to maintain homeostasis (balance). It is secreted by the adrenal cortex in response to stressful situations, but it also has many other roles that are essential for the proper functioning of the body. In this article, you will learn what cortisol is, what effects it has on the body, how to reduce cortisol, and learn about how tests can detect elevated cortisol in the body.
Cortisol = Stress Hormone? What is cortisol?
Cortisol is a hormone that is secreted by the adrenal glands, small glands located above the kidneys. This hormone is part of the endocrine system and plays a key role in the regulation of a number of bodily functions, including:
- Stress response: when you find yourself in a stressful situation, the body triggers a “fight or flight” mechanism that increases cortisol levels. This increases energy and focus to overcome the challenging situation.
- Blood sugar regulation: cortisol helps maintain stable blood sugar levels by promoting the production of glucose in the liver.
- Immune system: Cortisol has anti-inflammatory properties and helps regulate the body’s immune response.
- Blood pressure regulation: Cortisol levels affect blood pressure, which is important for the proper functioning of the cardiovascular system.
Cortisol production is controlled by the pituitary gland and hypothalamus, two parts of the brain that are key to regulating hormonal balance. When the body is stressed, the hypothalamus secretes the hormone CRH (corticotropin-releasing hormone), which stimulates the pituitary gland to secrete ACTH (adrenocorticotropic hormone). ACTH then stimulates the adrenal glands to start producing cortisol. Cortisol levels naturally change throughout the day. They are highest in the morning, which helps the body “wake up” and prepare for the day. During the day, levels gradually drop and are lowest in the evening as the body prepares for sleep.
Symptoms of high cortisol in the body
Although cortisol is essential for survival, prolonged elevated levels can have a negative impact on health. Chronic stress leads to a constant increase in cortisol, which can cause various problems. The most common symptoms include:
- Weight gain, especially in the abdomen (the so-called, cortisol belly): Cortisol promotes fat storage, especially in the abdominal area, known as visceral fat. It can also cause muscle loss and water retention.
- Thin skin and bruising easily: Cortisol weakens the skin and makes it easier for bruises to form and for wounds to heal.
- Fatigue and weakness: Cortisol can cause fatigue in the long term because excessive cortisol production leads to depletion of the body’s energy reserves.
- Sleep problems (insomnia): High levels of cortisol can disrupt the sleep cycle and cause insomnia or difficulty falling asleep. Cortisol is normally supposed to be highest in the morning and drop in the evening but can be elevated at night if imbalanced.
- Mood changes, anxiety and irritability: Cortisol can directly affect mood, leading to increased anxiety, irritability or even depression.
- Increased blood pressure: Cortisol has the ability to retain sodium in the body, which can lead to increased blood pressure.
- Increased blood sugar: Cortisol stimulates the release of glucose from the liver into the blood, which can increase the risk of insulin resistance and type 2 diabetes.
- Lowered immunity: Cortisol suppresses the immune system, which can make you ill more often or more susceptible to infections.
- Muscle loss and weakness: Cortisol causes protein breakdown, which can lead to loss of muscle mass and an overall feeling of weakness.
Long-term health risks of high cortisol: If cortisol is elevated long-term, it can lead to more serious health problems, including:
- Cushing’s syndrome: This condition is caused by excessive cortisol production and can cause obesity, high blood pressure, diabetes, and osteoporosis.
- Cardiovascular disease: High cortisol levels increase the risk of heart disease, especially if high blood pressure or sugar levels are also present.
- Reduced bone density: Cortisol weakens bones and can lead to osteoporosis.
Cortisol test: how to know if I have elevated cortisol?
If you suspect you have high cortisol, the best way to confirm this is to have your cortisol levels measured through a medical test. There are several methods to check the level of cortisol in your body:
- Saliva test: This is one of the most accurate ways to measure cortisol levels. The test is usually done four times a day (morning, noon, evening, and bedtime) because cortisol levels change throughout the day. This way it can be used to see if cortisol levels are elevated at times when they should be low (for example, in the evening).
- Blood test: your doctor may take a blood sample to check your cortisol levels. A blood test is usually done in the morning when cortisol levels are highest. If cortisol levels are significantly higher than normal, this may indicate a problem.
- Urine test: A 24-hour urine test may also be done, which measures the amount of cortisol excreted in the urine throughout the day. This gives an overall picture of how much cortisol the body produces over a 24-hour period.
- Dexamethasone suppression test: In this test, you are given a small dose of a synthetic corticosteroid (dexamethasone) that is normally supposed to lower cortisol levels. If your cortisol levels remain high, this may indicate that you have a problem with cortisol regulation.
How to lower cortisol levels?
To reduce cortisol levels, it is important to focus on reducing stress. Regular exercise, especially moderate-intensity exercise, helps the body reduce cortisol levels and improves mood. A diet rich in antioxidants, omega-3 fatty acids and vitamins (especially C and B) helps the body cope with stress better and supports proper adrenal function. Getting enough sleep is also key to maintaining proper cortisol levels. It is recommended to sleep a minimum of 7 hours a day. There is evidence that certain probiotics can help alleviate the negative effects of stress on the body. Probiotics have a beneficial effect on the health of the gut microbiome and according to recent studies, can also affect the brain and mood. This connection between the gut and the brain is known as the “gut-brain axis“. Gut health can directly affect mental health and stress management.
How can multi-species probiotics reduce cortisol levels?
The gut and the brain are connected through the vagus nerve, the immune system and hormonal signals. This complex communication system allows gut bacteria (probiotics) to influence brain function and stress regulation. Probiotics can stimulate this main communication channel between the gut and the brain. Activation of the vagus nerve can lead to lower cortisol levels and calm the stress response.
Reduction of inflammation
Chronic stress and elevated cortisol levels can lead to increased inflammation in the body. This inflammation can further worsen and contribute to the production of cortisol as part of the immune response. Probiotics help reduce inflammation by producing anti-inflammatory immunoglobulins, acting as a preventative against colonisation by pathogenic microorganisms and restoring balance in the gut microbiota.
Strengthening the intestinal barrier
A healthy intestinal barrier prevents the penetration of harmful substances from the intestines into the bloodstream, preventing inflammatory and stress reactions. A “leaky gut” can increase inflammation and stress, leading to higher cortisol levels. Probiotics help to strengthen the gut barrier, reducing the risk of stress reactions.
- Improving gut barrier: probiotics support the health of the intestinal lining and help restore the natural barrier function of the gut, minimising the penetration of toxins and bacteria that could trigger inflammation and increase cortisol levels.
Production of neurotransmitters
Probiotics support the production of important neurotransmitters that affect mood and mental health, such as serotonin, dopamine and GABA (non-protein gamma-aminobutyric acid). These neurotransmitters play a key role in regulating stress and emotions.
- Serotonin and GABA: A healthy gut microbiome, supported by probiotics, increases the production of serotonin and GABA, which are known to reduce stress and anxiety. Improved mood and stress management leads to a decrease in activation of the HPA (hypothalamic-pituitary-adrenal) axis, which regulates cortisol production.
Improving mood and reducing anxiety
Probiotics can directly reduce symptoms of anxiety and depression, helping to better manage stress. Research has shown that reducing anxiety and improving mood through probiotics leads to a lower stress response and lower cortisol production.
Studies: clinical studies show that a combination of targeted probiotic strains, such as Lactobacillus and Bifidobacterium, can reduce cortisol levels in people who are stressed. Study participants also reported better mental state, less anxiety, and improved sleep, all factors associated with lower cortisol levels. Other studies show that probiotics can reduce cortisol in patients with depression, patients who can certainly be described as chronically stressed.
Which probiotic strains are most effective against stress and for reducing cortisol?
Not all probiotics have the same effect in the body to cope with stress. What is important is the combination and interplay of individual bacterial strains. While previous research has mainly focused on the health effects of individual micro-organisms, this latest and most comprehensive study to date from King’s College London shows that the teamwork of micro-organisms is actually much more effective than the individual work of a single bacterial species. In fact, gut bacteria work better as a team. If you need advice on choosing probiotics, contact our expert medical team.
When and how to take probiotics to lower cortisol?
If you decide to start taking probiotics to support stress management, it is important to choose supplements that contain strains associated with psychobiotic effects. Focus on high-quality probiotic supplements whose effect has been proven in scientific studies. Taking probiotics is recommended for at least 4 to 6 weeks to see noticeable results. However, this is individual for each person. In addition, it is important to combine probiotics with a healthy diet rich in prebiotics (fibres that support the growth of good bacteria), which can be found in food but also in dietary supplements. If you feel constantly stressed or suspect elevated cortisol levels in your body, consult your doctor. Proper diagnosis and treatment of the problem can prevent long-term health complications.
Source: https://www.sciencedirect.com/science/article/abs/pii/S1756464618306170
