Cortisol: Find Out How It Affects Your Health

Have you ever wondered why you get a racing heartbeat, shortness of breath, or begin to sweat more when you’re anxious or nervous? These physical symptoms are a result of a hormone in your body known as cortisol. While this type of reaction feels uncomfortable, cortisol serves an important purpose. Known as the “stress hormone”, cortisol l is released when you encounter a physical or psychological stressor. A stressor can be anything from being cut off in traffic, to getting injured, to an argument with your coworker or spouse. For this reason, cortisol is commonly known as the “stress hormone”. When your cortisol is in balance, it helps you to adapt well to stress. However, if your cortisol levels are too high or too low, it can be harmful to your organs or even fatal in extreme cases. (10) Read on to learn the effects of cortisol on your health, and what can happen with either insufficient or excess cortisol levels. Cortisol is one of the main hormones that regulate your sleep-wake cycle.

What is cortisol?

Cortisol is a steroid hormone that is synthesized in your body from cholesterol. Although cholesterol may be obtained from the diet, it is also manufactured by your liver. It then follows one of several steroidogenic pathways in the adrenal glands, where it is eventually converted to cortisol, which is the active form of the hormone. The adrenal glands are endocrine glands that produce hormones including cortisol, aldosterone, and adrenaline. The production and release of cortisol, depends on the hypothalamus-pituitary-adrenal axis (HPA axis). These three endocrine glands work together to regulate cortisol and maintain homeostasis within your body. When you experience a stressor, it activates the parvocellular nuclei (PVN) in your hypothalamus gland. This leads to a release of corticotrophin-releasing hormone (CRH). CRH acts on the anterior pituitary gland to promote the production and secretion of adrenocorticotrophic hormone (ACTH). ACTH is released into your veins and reaches the adrenal cortex, where it binds to the melanocyte type-2 receptor (MC2R) on cells and stimulates cortisol release into the bloodstream. This process is regulated by negative feedback inhibition, which means that cortisol can inhibit ACTH and CRH secretion to maintain homeostasis. (5)(10) In other words, as more cortisol is secreted by the adrenal glands, the negative feedback loop ensures ACTH and CRH secretion is decreased.

How does cortisol affect health?

When released into the bloodstream, cortisol has several physiologic effects, including:

• Adjusting respiration and muscle tension
• Down-regulating digestive and reproductive functions
• Increasing blood glucose level
• Increasing heart rate
• Raising blood pressure
• Reducing inflammation (1)(4)

The purpose of these effects is to allow your brain and body to respond and protect you from a stressor. Cortisol is released when you encounter a real threat, such as injury, or a perceived threat, such as stress at work. Beyond the stress response, cortisol also plays a role in your wake-sleep cycle and in maintaining serum glucose (blood sugar) levels. Cortisol levels should naturally peak in the morning between 6 am and 9 am, and be at their lowest from 11 pm and 1 am. As you are fasting overnight, cortisol levels begin to rise around 4 am in order to maintain blood glucose levels. (10) While cortisol is essential to maintaining daily functions, chronic stress and other lifestyle factors can result in cortisol dysfunction. Dysfunction may involve depletion of cortisol, low free (or unbound) cortisol, issues with cortisol secretion or CRH function, glucocorticoid receptor resistance, or hypersensitivity of the negative feedback system. (4)

Insufficient cortisol

Since cortisol is made in the adrenal glands, sufficient adrenal function is necessary to produce the hormone. Adrenal insufficiency can come in several forms, including Addison’s disease, secondary adrenal insufficiency, and tertiary adrenal insufficiency. (13) Some of the factors that contribute to adrenal insufficiency include:

• Autoimmune disease or infections such as tuberculosis (Addison’s disease)
• Conditions that affect the pituitary gland, such as tumors, infections, or genetic diseases (secondary adrenal insufficiency)
• Long-term use of corticosteroids followed by abruptly stopping the medication (tertiary adrenal insufficiency) (13)

Addison’s disease, also known as adrenal insufficiency, is characterized by low cortisol levels. In Western countries, about 120 people per million suffer from this disease. The signs and symptoms include fatigue, weight loss, vomiting, diarrhea, abdominal pain, and behavioral changes. Corticosteroid and mineralocorticoid replacement therapies are used for the treatment of Addison’s disease. (14) Addison’s disease can result in fatigue, behavioral changes, and digestive symptoms. Another serious and potentially life-threatening condition related to insufficient cortisol is central adrenal insufficiency (CAI). CAI can be caused by either pituitary disease or impaired hypothalamic function, resulting in ACTH deficiency and other potential pituitary hormone deficiencies. When ACTH secretion decreases, cortisol secretion subsequently decreases as well resulting in several symptoms such as hypoglycemia, lethargy, apnea, jitteriness, and seizures. (9)

Excess cortisol

Cortisol imbalance can also affect your health when your body produces too much cortisol. While normal increases in cortisol levels occur as a result of moderate to intense exercise (6), prolonged cortisol exposure may lead to certain health conditions. Causes of high cortisol levels include:

• Children’s exposure to maternal postnatal depression
• Chronic stress, including shift work and intensive training in endurance athletes (3)(5)(7)(12)

Adapting methods to minimize or manage stress can help with cortisol dysfunction. Lifestyle changes such as cognitive-behavior stress management have been shown to help lower cortisol levels in patients experiencing high levels of stress, such as in cancer treatment (2) High cortisol symptoms, signs, and outcomes include:

• A higher body mass index (BMI) or obesity
• An irregular inflammatory response when injured, resulting in impaired healing
• Inflammation, depression, and pain
• Negative effects on cognition; may contribute to Alzheimer’s disease pathology (4)(8)(11)

A condition called Cushing’s syndrome is characterized by elevated blood cortisol levels over an extended time. Some of the signs and symptoms of Cushing’s are obesity, hypertension, depression, decreased libido, and skin irregularities such as hirsutism or acne. The disorder can be caused by tumors on the pituitary gland or a benign adrenocortical adenoma. Interestingly, Cushing’s can also occur as a result of treatment with synthetic glucocorticoids. (10) Balance your cortisol levels by staying active.

How to balance cortisol

When it comes to managing cortisol, balance is key. Luckily, there are several evidence-based steps we can take to help manage our stress responses and promote normal cortisol levels.

Engage in regular exercise

Physical activity is one of the most effective strategies for balancing cortisol levels. Exercise has been widely studied for its anti-anxiety and anti-stress benefits. (19) Not only does exercise help improve mental health and mental outlook, but it directly counters many of the negative impacts of hypercortisolemia (prolonged excess cortisol levels). Even a single bout of aerobic exercise (e.g., brisk walking, biking, dancing) can counteract the stress response, after which the blood vessels are signaled to relax and blood pressure lowers. (16) Exercise releases a cascade of signaling molecules and hormones that directly counteract many of the most pervasive aspects of stress. For example, exercise is known to reduce inflammation and improve metabolism. (16) These effects are found across a range of exercise intensities and durations, meaning that you don’t have to be a triathlete to procure these benefits. (16) Even small bouts of exercise can make a big difference in countering an overactive stress response. A recent study found that moderate-intensity exercise was actually slightly more effective at improving mental health and reducing inflammation than high-intensity training. (16)

Get enough quality sleep

Research has demonstrated that sleep is one of the most important factors for balancing cortisol levels. Unfortunately, when your sleep is disrupted, so too are many key recovery pathways, including cognitive health and endocrine function. Conversely, a chronically activated stress response can cause further disruptions to our circadian rhythm—the body’s natural sleep-wake cycle. (15) Practicing good sleep hygiene is one of the best approaches you can use to improve your circadian rhythm. Avoiding blue light exposure (e.g., smartphones, computers, televisions), avoiding food consumption for two hours prior to bedtime, and trying your best to follow a consistent sleep schedule are effective strategies. These actions signal the body that it is time to slow down, promoting restful and restorative sleep. (4)(14)

Practice mindfulness and minimalism

Whether it’s reading an engaging book, playing an instrument, or learning to paint, there is something inherently enjoyable about feeling focused and undistracted. Contrast that with the all too familiar feeling of overstimulation. If you find that your attention is constantly pulled in multiple directions or you’re often distracted by social media, finding time to unplug can do wonders for bringing a sense of calm to an otherwise overactive mind. Establishing a daily meditation practice is a great place to start. Practicing meditation and mindfulness can help us better focus our attention on the items that we find to be meaningful and valuable. The exact mechanisms by which meditation influences cognitive function is an active area of investigation. Mindfulness meditation has been found to lower overall anxiety and reduce serum cortisol levels, which researchers suggested may be a result of increased prefrontal cortex activity and improved regulation of the amygdala. (7)(23) Consuming a Mediterranean-style diet can help improve your mood and reduce stress levels.

Consume a healthy diet

The foods you eat (and do not eat) play a crucial role in how you may feel on a day-to-day basis. While this likely comes as no surprise, it is often understated just how connected your diet is to your mental well-being. Studies have shown that adaptogenic herbs, such as Rhodiola rosea and Withania somnifera (ashwagandha), can effectively reduce cortisol levels and improve symptoms of stress. (13)(15) Research has also demonstrated that a diet rich in dietary fiber and phytonutrients (health-promoting plant compounds) can have a positive effect on perceived mood, stress, and overall quality of life. (2)(6) Consuming a diet rich in a variety of plant foods can ensure you’re getting the phytonutrients, vitamins, and minerals necessary for optimal health. Fruits and vegetables contain an array of nutrients that have been shown to fight oxidative stress, control inflammation, improve blood flow, enhance cognition, and encourage a healthy gut microbiome. (17) Diets high in refined sugars and carbohydrates can negatively impact levels of oxidative stress and cortisol, while healthy eating habits such as adherence to the Mediterranean diet have been shown to counteract these effects. (5) Not only can diets like the Mediterranean diet, rich in fruits, vegetables, seafood, nuts, and olive oil, help with stress management, but they’ve also been linked to improved overall mental health attributed to their role in regulating inflammation throughout the body. (5)

Focus on the gut

Finding ways to encourage a healthy and robust microbiome can have profound downstream impacts on your well-being. Supplements such as probiotics and prebiotics have been shown to help reduce stress and improve mental outlook. (8)(24) Unfortunately, modern lifestyles mean that people are spending more time indoors and consuming greater amounts of processed foods, which are directly harmful to the microbiome. These poor lifestyle habits can shift the balance of microbes in the gut, leading to a greater prevalence of pro-inflammatory “bad” bacteria and fewer “good” microbes in the gut, producing chronic levels of low-grade inflammation. (11)(21) Like any ecosystem, a healthy gut thrives on balance. Too many harmful microbes can be highly disruptive, resulting in significant health consequences. Among their many responsibilities, microbes work hand-in-hand with the brain through both the production of neurotransmitters and direct signaling across the vagus nerve. While the research continues to evolve, animal studies have shown a direct link between the microbiome and the regulation of the stress response. (20) Recent human research has added further credibility to these findings, demonstrating a direct connection between particular harmful gut microbes (e.g., Bacteroidetes) and depressive symptoms. (10) Further understanding the complex relationship between us and our microbes promises to be a crucial step in promoting mental wellbeing.

The bottom line

While stress may feel unavoidable, it is important to remember that we are not powerless against it. Taking active steps to manage our cortisol levels can do wonders for our physical and mental health and wellness, and we are fortunate to have an abundance of research highlighting the most effective strategies. It is important to remember that these findings are not all or nothing! Taking even small actions in any of these areas is a great step to take in fighting back against some of the more pervasive influences of our modern lifestyles.