Cortisol x Gut Health
I always thought cortisol was a bad word. A bad thing. Something to be avoided.
I first heard of it when I was in high school, associated with belly fat, so it’s probably not shocking that it became Voldemort-adjacent for me: something awful, evil, dangerous, and to be avoided at all cost.
Quick quiz: what’s your association with cortisol? Do you think it’s bad? Something you have excess of and need to reduce? Something that’s causing problems in your life?
My guess would be that your answer to all of those questions is yes. And you will probably be partially right, and partially wrong.
Here’s the real deal: cortisol is not “bad” or “good.” Like anything else, it has it’s place, it plays an important role, but in excess it’s bad. And the problem is that most of us have excess cortisol. Let’s break it down!
What Is Cortisol
Cortisol is a steroid hormone produced by the adrenal glands, which are located on top of the kidneys. It belongs to a class of hormones called glucocorticoids and is synthesized from cholesterol in a series of enzymatic reactions. Cortisol plays a crucial role in various physiological processes, including metabolism, immune function, inflammation regulation, and stress response.
Gluconeogenesis and Glycogenolysis: One of cortisol's key functions is to promote gluconeogenesis, the synthesis of glucose from non-carbohydrate precursors (such as amino acids and glycerol) in the liver. By stimulating gluconeogenesis, cortisol helps raise blood glucose levels during periods of fasting or stress, ensuring a constant energy supply for the brain and other glucose-dependent tissues. Additionally, cortisol promotes glycogenolysis, the breakdown of glycogen stored in the liver and muscles, to release glucose into the bloodstream.
Anti-inflammatory and Immunosuppressive Effects: Cortisol has potent anti-inflammatory and immunosuppressive properties, which are essential for modulating the body's immune response and maintaining immune homeostasis. During acute stress or injury, cortisol helps dampen inflammatory reactions by inhibiting the production of pro-inflammatory cytokines and suppressing immune cell activity. While this anti-inflammatory response is crucial for resolving acute inflammation and preventing tissue damage, chronic elevation of cortisol levels can lead to immune dysfunction and increased susceptibility to infections.
Regulation of Stress Response: Cortisol is a key component of the body's stress response system, known as the hypothalamic-pituitary-adrenal (HPA) axis. In response to stressors such as physical trauma, psychological stress, or environmental challenges, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the anterior pituitary gland to secrete adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal glands to produce and release cortisol into the bloodstream. Cortisol acts on various target tissues, including the liver, muscles, and adipose tissue, to mobilize energy resources and prepare the body to cope with the stressor.
Regulation of Blood Pressure and Vascular Tone: Cortisol plays a role in regulating blood pressure and vascular tone by modulating the sensitivity of blood vessels to vasoconstrictors such as catecholamines (e.g., adrenaline). Cortisol promotes vasoconstriction, particularly in peripheral blood vessels, which helps elevate blood pressure and maintain vascular tone during stress. Additionally, cortisol influences fluid and electrolyte balance by enhancing sodium reabsorption in the kidneys and increasing urinary excretion of potassium.
Maintenance of Homeostasis: Overall, cortisol helps maintain homeostasis in the body by coordinating metabolic, immune, and stress responses to ensure the body's survival and adaptation to changing environmental conditions. While cortisol is essential for physiological function, dysregulation of cortisol secretion or chronic elevation of cortisol levels (as seen in conditions such as Cushing's syndrome or chronic stress) can have detrimental effects on health, including metabolic disorders, immune dysfunction, and mood disturbances.
Excess Cortisol
While cortisol is essential for maintaining homeostasis and adapting to stressors, chronic elevation of cortisol levels can have detrimental effects on health. Several factors can contribute to dysregulated cortisol secretion and persistently high levels:
Chronic Stress: Prolonged exposure to psychological stressors, such as work pressure, relationship problems, financial worries, or traumatic events, can chronically activate the hypothalamic-pituitary-adrenal (HPA) axis, leading to sustained cortisol release.
Sleep Deprivation: Inadequate or poor-quality sleep can disrupt the normal circadian rhythm of cortisol secretion, resulting in elevated cortisol levels throughout the day.
Unhealthy Lifestyle Habits: Factors such as poor diet, sedentary lifestyle, excessive caffeine intake, and substance abuse (e.g., alcohol, nicotine) can contribute to dysregulated cortisol metabolism and hypersecretion.
Medical Conditions: Certain medical conditions, such as Cushing's syndrome (excess cortisol production), adrenal tumors, pituitary disorders, or chronic inflammatory diseases, can cause elevated cortisol levels.
Symptoms of Elevated Cortisol: Persistently high cortisol levels can manifest in various physical, emotional, and cognitive symptoms, including:
Weight Gain: Cortisol promotes fat storage, particularly in the abdominal area, leading to weight gain, especially around the midsection.
Insomnia: Elevated cortisol levels can disrupt sleep patterns, causing difficulty falling asleep, frequent awakenings during the night, or early morning awakenings.
Fatigue: While cortisol helps mobilize energy reserves during times of stress, chronic elevation of cortisol levels can eventually lead to adrenal fatigue or burnout, resulting in persistent fatigue and low energy levels.
Anxiety and Irritability: Excessive cortisol can exacerbate feelings of anxiety, nervousness, and irritability, as it sensitizes the central nervous system to stressors and heightens emotional reactivity.
Digestive Issues: Cortisol can affect digestive function by altering gut motility, increasing gastric acid secretion, and disrupting the balance of gut microbiota, leading to symptoms such as indigestion, bloating, abdominal discomfort, or changes in bowel habits.
Immune Suppression: Prolonged exposure to high cortisol levels can suppress immune function, making individuals more susceptible to infections, allergies, and autoimmune disorders.
Cognitive Impairment: Chronic stress and elevated cortisol levels have been associated with cognitive deficits, including impaired memory, attention, and executive function.
Low Cortisol
Hypocortisolism refers to abnormally low levels of cortisol production or insufficient cortisol activity in the body. This condition can arise from various causes, including adrenal insufficiency, pituitary dysfunction, or chronic stress leading to adrenal fatigue. From a polyvagal perspective, which considers the role of the vagus nerve in regulating physiological and emotional states, low cortisol levels may be associated with dysregulation of the autonomic nervous system (ANS) and altered vagal tone.
Causes of Low Cortisol:
Primary Adrenal Insufficiency (Addison's Disease): This condition occurs when the adrenal glands fail to produce sufficient cortisol due to autoimmune destruction, infections, or genetic disorders affecting adrenal function.
Secondary Adrenal Insufficiency: In this case, the pituitary gland fails to release adequate adrenocorticotropic hormone (ACTH), which stimulates cortisol production by the adrenal glands. Causes include pituitary tumors, pituitary surgery, or prolonged corticosteroid use, leading to suppression of the HPA axis.
Chronic Stress and Adrenal Fatigue: Prolonged exposure to chronic stressors can dysregulate the HPA axis, leading to downregulation of cortisol production and adrenal exhaustion, a phenomenon often referred to as adrenal fatigue.
Symptoms of Low Cortisol: Low cortisol levels can manifest in a variety of physical, emotional, and cognitive symptoms, including:
Fatigue and Weakness: Individuals with hypocortisolism may experience persistent fatigue, weakness, and reduced stamina, as cortisol plays a crucial role in mobilizing energy reserves and maintaining metabolic function.
Hypotension: Low cortisol levels can lead to decreased vascular tone and blood pressure regulation, resulting in orthostatic hypotension (dizziness upon standing) and lightheadedness.
Hypoglycemia: Cortisol helps regulate blood glucose levels by promoting gluconeogenesis and glycogenolysis. Insufficient cortisol production can result in hypoglycemia (low blood sugar), leading to symptoms such as shakiness, confusion, and sweating.
Weight Loss and Muscle Wasting: Inadequate cortisol activity can impair protein metabolism and lead to muscle breakdown (catabolism), resulting in weight loss, muscle weakness, and reduced muscle mass.
Mood Changes: Low cortisol levels may contribute to mood disturbances, including depression, anxiety, irritability, and emotional dysregulation, as cortisol plays a role in modulating stress responses and regulating mood.
Digestive Issues: Cortisol deficiency can affect gastrointestinal function, leading to symptoms such as abdominal pain, nausea, diarrhea, or constipation. Dysregulation of the autonomic nervous system and altered vagal tone may further exacerbate digestive symptoms.
Cognitive Impairment: Hypocortisolism can impair cognitive function, including memory, concentration, and attention, due to disruptions in neurotransmitter activity and reduced cerebral blood flow.
Polyvagal Perspective: From a polyvagal theory standpoint, dysregulation of the autonomic nervous system, particularly altered vagal tone, may contribute to the symptoms associated with low cortisol levels. The vagus nerve plays a critical role in regulating physiological states, emotional responses, and social engagement behaviors. Dysfunction of the vagus nerve can lead to imbalances in the sympathetic and parasympathetic branches of the ANS, affecting stress responses, emotional regulation, and visceral functions.
In individuals with low cortisol levels, dysregulation of the autonomic nervous system may manifest as altered vagal tone, characterized by decreased parasympathetic activity and increased sympathetic arousal. This dysregulation can contribute to symptoms such as fatigue, mood disturbances, digestive issues, and cognitive impairment. Additionally, chronic stress and adrenal fatigue may further disrupt the balance of the autonomic nervous system, exacerbating symptoms and perpetuating the cycle of dysfunction.
The Bi-Directional Relationship with the Gut
The interaction between cortisol and gut health is bidirectional, with stress influencing gut function and gut health impacting cortisol levels. Stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis stimulates cortisol secretion, which can modulate various aspects of gut physiology, including motility, permeability, and immune function. Conversely, disturbances in gut microbiota composition, termed dysbiosis, can activate immune cells in the gut-associated lymphoid tissue (GALT), leading to cortisol release and HPA axis activation.
Several mechanisms underlie the effects of cortisol on gut health, including intestinal permeability, gastrointestinal motility, immune regulation, and gut microbiota modulation. Chronic elevation of cortisol levels can disrupt the integrity of the intestinal barrier, inhibit smooth muscle contraction in the GI tract, suppress immune responses in the gut, and modulate gut microbial composition and function.
Chronic elevation of cortisol levels, as observed in conditions of prolonged stress, can have detrimental effects on gut health and contribute to the pathogenesis of various GI disorders, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), functional dyspepsia, gastroesophageal reflux disease (GERD), constipation, and diarrhea.
How Stress Affects Gut Health & Constipation
Chronic stress can contribute to gut dysmotility and constipation through multiple mechanisms:
Activation of the HPA axis leads to increased cortisol secretion, which can inhibit gastrointestinal motility and delay transit time.
Stress-induced alterations in gut microbiota composition disrupt microbial diversity and function, potentially exacerbating constipation.
Psychological stressors, such as anxiety and depression, can further exacerbate gut symptoms, including constipation, through the gut-brain axis.
How Gut Health Affects Cortisol Levels
Gut health influences cortisol levels through several pathways:
Gut microbiota produce metabolites that interact with the HPA axis, modulating cortisol secretion. For example, short-chain fatty acids (SCFAs) produced by gut bacteria can influence cortisol production and sensitivity.
Intestinal barrier dysfunction and inflammation, commonly observed in gut-related disorders, may promote cortisol dysregulation by activating immune responses and stimulating cortisol release.
Nutritional factors, such as dietary fiber and prebiotics, can support gut health and microbial balance, indirectly influencing cortisol levels.
Improving Gut Health to Regulate Cortisol
Improving gut health can help regulate cortisol levels through various mechanisms:
Microbiota-Gut-Brain Axis: The gut microbiota plays a crucial role in regulating the HPA (hypothalamic-pituitary-adrenal) axis, which controls cortisol secretion. Dysbiosis, or imbalance in gut bacteria, can lead to HPA axis dysregulation, resulting in abnormal cortisol levels. By promoting a healthy balance of gut bacteria, through dietary changes or probiotic supplementation, you can support proper HPA axis function and cortisol regulation.
Short-Chain Fatty Acids (SCFAs): Certain beneficial bacteria in the gut produce short-chain fatty acids (SCFAs) through the fermentation of dietary fiber. SCFAs, such as butyrate, acetate, and propionate, have been shown to modulate HPA axis activity and reduce cortisol levels. By promoting the growth of SCFA-producing bacteria through fiber-rich diets, you can support cortisol regulation.
Intestinal Permeability (Leaky Gut): A compromised gut barrier, often referred to as "leaky gut," can lead to the translocation of harmful substances from the gut lumen into the bloodstream, triggering an inflammatory response and HPA axis activation. Chronic activation of the HPA axis can lead to dysregulated cortisol secretion. By maintaining gut barrier integrity through proper nutrition and lifestyle factors, you can prevent leaky gut and reduce cortisol dysregulation.
Neurotransmitter Production: The gut microbiota also influences the production of neurotransmitters, including serotonin and gamma-aminobutyric acid (GABA), which play roles in stress regulation and cortisol modulation. Serotonin, for example, is primarily produced in the gut and can influence cortisol secretion through its effects on the HPA axis. By promoting a healthy gut microbiota, you can support optimal neurotransmitter production and cortisol regulation.
Anti-Inflammatory Effects: Chronic inflammation in the gut can contribute to HPA axis dysregulation and cortisol imbalances. By reducing gut inflammation through dietary modifications, such as avoiding inflammatory foods and incorporating anti-inflammatory nutrients, you can help restore HPA axis function and cortisol balance.
How to Improve Gut Health
Here are some strategies that will help you strengthen your gut health, thereby regulating your cortisol levels:
Eating More Soluble Fiber: Soluble fiber forms a gel-like substance in the digestive tract, which helps to soften stools and promote regular bowel movements. By improving bowel regularity, soluble fiber can reduce the risk of constipation and minimize stress on the gut. Additionally, soluble fiber serves as a substrate for beneficial gut bacteria, promoting their growth and fermentation activity. This fermentation process produces short-chain fatty acids (SCFAs), such as butyrate, which have anti-inflammatory effects and can help regulate cortisol levels. Legumes have the highest concentration of soluble fiber.
Eating More Insoluble Fiber: Insoluble fiber adds bulk to the stool and accelerates transit time through the digestive tract, aiding in the removal of waste and toxins from the body. By preventing constipation and promoting regularity, insoluble fiber supports overall gut health and reduces the likelihood of gut dysbiosis, which can contribute to cortisol dysregulation. Best sources: fruits with edible seeds & skins, like strawberries, raspberries, blackberries, kiwi, and fresh figs.
Eating Prebiotic Foods & Resistant Starches: Prebiotic foods contain indigestible fibers that serve as fuel for beneficial gut bacteria, promoting their proliferation and diversity. By nourishing the gut microbiota, prebiotics help maintain a healthy balance of bacteria in the gut, which is essential for optimal digestive function and immune regulation. Resistant starches, which resist digestion in the small intestine and reach the colon intact, also serve as prebiotics and support gut health. Best sources: onions, leeks, garlic, sunchokes, jicama, green bananas, legumes, cooked & cooled potatoes, raw oats.
Consuming Probiotics: Probiotics are beneficial bacteria that can colonize the gut and confer various health benefits, including improved digestion, enhanced immune function, and reduced inflammation. By replenishing and diversifying the gut microbiota, probiotics help support gut barrier integrity and reduce gut permeability, which can help regulate cortisol levels and mitigate the effects of chronic stress on the body. Best sources: probiotic supplements (I like Seed, Cymbiotika’s, and Organic Olivia); kimchi, sauerkraut, & other fermented vegetables; and water kefir. Be careful with yogurt, most yogurts sold on the market today are not properly fermented, and even if they are, adding sugar to it takes the benefits away.
Mindfulness: Mindfulness practices, such as meditation, deep breathing exercises, and yoga, have been shown to reduce stress and promote relaxation by modulating the body's stress response system. By activating the parasympathetic nervous system (PNS) and dampening the activity of the sympathetic nervous system (SNS), mindfulness techniques can help counteract the effects of chronic stress on gut function and cortisol secretion. Tip: just 2 minutes of closing your eyes, and paying attention to your breathing has profound effects.
Movement/Exercise: Regular physical activity has been associated with numerous health benefits, including improved gut motility, enhanced digestion, and reduced inflammation. Exercise stimulates the release of endorphins, neurotransmitters that promote feelings of well-being and reduce stress. By promoting gut motility and optimizing digestion, exercise can indirectly influence cortisol levels and contribute to overall gut health. Tip: take 20 minute walks after meals & aim for some strength training a few times a week.
Hydrating with Mineral-Rich Beverages & Hydrating Fruits: Adequate hydration is essential for maintaining proper digestive function and supporting gut health. Consuming mineral-rich beverages, such as nettle infusions, lemon water, and fresh coconut water; provides essential nutrients and electrolytes that support optimal hydration and electrolyte balance. Hydrating fruits like melons, kiwi, and papayas also contribute to hydration while providing additional nutrients and antioxidants that support gut health and mitigate the effects of stress on the body.
Eating Polyphenol-Rich Foods: Polyphenols are plant compounds found in fruits, vegetables, nuts, seeds, and beverages like green tea and red wine. These compounds have antioxidant and anti-inflammatory properties and can help protect against oxidative stress and inflammation in the gut. By reducing gut inflammation and supporting gut barrier function, polyphenols may help regulate cortisol levels and improve overall gut health. Best sources: blueberries, cacao, matcha, walnuts, flaxseeds, chia seeds, artichokes, kale, spinach, onions, broccoli, and cabbage.
Avoiding Sugar & Artificial Sweeteners: Excessive consumption of sugar and artificial sweeteners can disrupt the balance of gut bacteria and contribute to gut dysbiosis, inflammation, and metabolic dysfunction. High sugar intake has been linked to increased cortisol secretion and chronic stress, while artificial sweeteners may alter gut microbiota composition and promote dysregulation of the HPA axis. Limiting intake of these substances can help maintain gut health and support cortisol regulation. Tip: avoid cane sugar, coconut sugar, maple syrup, and artificial sweeteners; and replace them with whole fruits like dates, bananas, and grapes.
Getting Enough Sleep: Adequate sleep is crucial for overall health and well-being, including gut health and cortisol regulation. Sleep deprivation and poor sleep quality can disrupt circadian rhythms, alter cortisol secretion patterns, and impair gut function. Prioritizing sleep hygiene practices and ensuring sufficient sleep duration can help restore normal cortisol rhythms and support optimal gut health. Tip: stop eating at least 11 hours before you intend to wake up the next day to optimize your sleep.
By incorporating these strategies into your daily routine, you can promote gut health, regulate cortisol levels, and support overall well-being. However, individual responses may vary, so it's essential to listen to your body and consult with a healthcare professional if you have specific concerns or medical conditions.
