Cortisol: role, regulation and relationship to diet
Cortisol is a steroid hormone secreted by the adrenal glands that plays a key role in the regulation of various physiological processes. It is mainly known for its role in the stress response, but it also has important links with diet and metabolism. In this article, we will discuss the function of cortisol, its regulation and the influence of diet on its levels and effects.
Cortisol is a key steroid hormone belonging to the glucocorticoid group. Its main function is to regulate glucose, fat and protein metabolism. Cortisol raises blood glucose levels by stimulating glycogenolysis and gluconeogenesis in the liver, which provides the body with an energy source in stressful situations. In addition, cortisol influences inflammatory, immune and stress responses.
Cortisol secretion is tightly regulated by the axial endocrine system, particularly the hypothalamic-pituitary-adrenal (HPTA) axis. Corticotropin-releasing hormone (CRH) produced by the hypothalamus stimulates the pituitary gland to secrete corticotropin (ACTH), which in turn stimulates the adrenal glands to produce cortisol. Cortisol levels in the body oscillate throughout the day, peaking in the morning and dropping in the evening.
Diet can have a significant impact on cortisol levels and function. Certain dietary factors can affect the body's ability to regulate cortisol secretion in response to stress. For example:
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Balanced diet: A diet rich in nutrients, including complex carbohydrates, high-quality protein and healthy fats, can help keep cortisol levels stable and improve the stress response.
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Avoiding excessive caffeine consumption: Excessive caffeine consumption can increase cortisol levels, which can lead to a chronic state of elevated levels of the hormone.
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Regular meals: Eating regular meals can help keep blood glucose levels stable, which can affect the body's ability to properly regulate cortisol.
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Antioxidant-rich diet: Eating plenty of antioxidant-rich fruit and vegetables can help protect cells from oxidative stress, which can affect cortisol secretion.
Cortisol level testing
The most common methods of testing cortisol levels are:
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Blood test: Measuring cortisol levels in blood drawn from a vein can provide information about its concentration in the body at a given time. This is usually done in the morning, as cortisol peaks at this time.
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Saliva tests: Salivary cortisol testing is a simple and non-invasive method that can be performed at home. Taking a saliva sample in the morning, afternoon and evening allows monitoring of the diurnal cycle of cortisol secretion.
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Urine tests: Testing urinary cortisol levels can also be useful to assess the average level of the hormone over a period of hours or days.
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Stimulation tests: In some cases, doctors may order stimulation tests, which involve the administration of a substance that stimulates cortisol secretion (e.g. synthetic ACTH) to assess the adrenal response.
Testing cortisol levels can provide valuable diagnostic information and can be helpful in understanding how diet and other factors affect its levels in the body. Always consult your doctor to interpret the results and determine further management of abnormal test results.
Cortisol plays a key role in the body's response to stress and in regulating metabolism. Diet plays an important role in regulating cortisol levels by influencing glycaemic stability and other metabolic factors. A balanced diet, avoiding excess caffeine and eating meals at regular times can help maintain healthy cortisol levels and improve overall metabolic health.
~Sandra Brudnik - hotel Alhambra dietician
I have been passionate about dietetics and cooking for many years and am constantly developing in this direction. I have completed a degree in clinical dietetics and have attended and continue to attend many training courses. Since 2020, I have been acting as a dietitian at the Alhambra Hotel and I work with the diets we prepare for you. A few years ago I was sceptical about Dr Dabrowski's diet, but I have found out first-hand what it does and I help our guests during Dr Dabrowski's Fasting.