Stress and Health
Stress has been blamed for everything from headaches to cancer, but the truth is, your stress response is beautifully designed to help you survive. It’s the abuse of that system with chronically stressful lifestyles that is the real source of health problems. If you are chasing your next meal with a spear, your blood sugar, heart rate, blood pressure and level of alertness should be high to fuel the chase. But if they are high because you are lying in bed chasing desperate thoughts about how to pay your bills, they are only fueling havoc in your body.
Because stress hormones are designed to alter almost every cell and system in your body, when stress is frequent, prolonged or chronic, it can negatively affect your health over time. The most common health issues arising from chronic stress result from elevated cortisol and its effects on blood sugar, insulin/insulin resistance, blood pressure, immune function, sleep, mood, memory, cell growth and repair, digestion and thyroid function. On the other hand, if your stress response system does not adequately meet the level of demand, health issues can develop related to adrenal fatigue and lower than optimal cortisol levels.
Below are brief descriptions of how the stress response affects some different aspects of health.
Stress and Adrenal Fatigue
Stress and Immune Function
Stress and Front-line Immune Defenses
Stress and Blood Sugar
Stress and Energy
Stress and Homeostasis
Stress and Tissue Health
Stress and Gut Integrity
Stress and Digestion
Stress and Thyroid Function
The constant demand of chronic stress on your stress response system, especially your adrenal glands, to produce hormones can also eventually result in adrenal fatigue. In 1998 Dr. James L. Wilson coined the term adrenal fatigue to describe a condition in which the stress response system is functioning and the adrenal glands are producing hormones but they are not meeting the level of demand – like a car stuck in a low gear trying to drive on the highway. Adrenal fatigue is very common, ranging from the tiredness you feel for a few days after recovering from an illness to debilitating fatigue that interferes with life and doesn’t go away with just rest.
Your adrenals produce over 50 hormones, including cortisol, adrenaline, aldosterone, DHEA, testosterone, progesterone and estrogen. Making them is a nutrient and energy intensive process. Too little of even one of the required nutrients hinders hormone production. Getting adequate amounts of all the right nutrients is more of a challenge with a stressful lifestyle for several reasons. Since stress slows down digestion, nutrient absorption decreases as well. Plus it’s very common for stressed people to eat on the fly, resort to junk food, and drive themselves with caffeine and sugary or salty snacks. Not only are these foods nutrient poor, but digesting and metabolizing them uses up nutrients they don’t replenish. Caffeine stimulates your adrenals to temporarily work harder but in the process further depletes them.
During adrenal fatigue, adrenal hormones like cortisol are below optimal levels. Cortisol plays a key role in many physiological processes; including helping maintain healthy blood sugar, blood pressure, thyroid function, immune function, digestion, mental focus, memory, and sex hormone levels. It is also the body’s most important anti-inflammatory agent. So when cortisol is low, it can adversely affect everything from your libido to allergic reactions to the quality of hydrochloric acid in your stomach. It also makes you feel tired, especially on rising, midmorning and midafternoon. To learn more about adrenal fatigue, please visit Dr. Wilson’s website adrenalfatigue.org. [return to top]
Adrenal stress hormones like adrenaline and cortisol trigger important changes in your immune function because they have the ability to regulate every immune cell in your body. The acute “fight or flight” stress response set off by adrenaline temporarily boosts certain aspects of innate, front-line immunity that help reduce the chance of infection from an injury sustained in the fight or flight – but also increase inflammation.
Although a certain amount of cortisol is necessary to stimulate proper immune function, the elevated cortisol accompanying stress partially suppresses the deeper, adaptive aspects of immunity that protect you over the long term from disease. If you are facing a lion, your body will quickly shift its energy resources from less immediate threats (like fighting cancer or a cold) to help you survive the critical danger in front of you.
With chronic stress, this cortisol-related decrease in immune function can leave you more susceptible to colds, flu and other infections, and potentially make you more vulnerable to serious illness and degenerative disease down the road, as well as to the development of allergies and autoimmune disorders. If stress continues over an extended period of time, your adrenals eventually may not be able to keep up with the continued demand (adrenal fatigue) and start producing too little cortisol to stimulate optimal immune function. Also, because cortisol is the primary anti-inflammatory agent in the body, inflammation can worsen and inflammatory conditions can flare if your adrenals do not produce enough.
When stress is chronic or prolonged, both the increase in inflammation and the decrease in overall immune function can begin to adversely affect your health. Illness, in turn, is an added stress, making it harder for fatigued adrenals to recover. To make matters worse, when people are stressed, they often do a poorer job of taking care of themselves – less laughter, sleep, exercise and healthy eating: more smoking, drinking, drugs and junk food. All of which can affect your immune system for the worse.
Consequently, whether your adrenal glands are fatigued or working optimally, chronic stress can have a negative impact on your immune function, making staying well an extra challenge. Managing your stress, supporting your adrenal glands and promoting strong immune function can significantly enhance your ability to stay well.* [return to top]
Your body has complex front line defenses where it meets the outside world – the surface of your skin, and respiratory, digestive and urogenital tracts. These include physical barriers (skin, mucous membranes), chemical reactions (acids, enzymes and other antimicrobial substances in mucus, tears, ear wax, sebum, sweat, digestive secretions), biological action (beneficial activity of the microorganisms in and on your body) mechanical action (coughing, sneezing, exhaling, sweating, peristalsis, elimination, skin shedding) and immune system activity. Your intestinal tract is actually the largest immune organ in your body and a very critical area of front-line defense.
Stress directly affects these defenses, primarily via adrenal hormones like adrenaline and cortisol, which have the ability to regulate immune cells throughout your body. It also modifies aspects of these other defense mechanisms – for example stress slows digestion, which can alter such things as digestive secretions and gut flora, and increases the inflammatory response. Short-term stress temporarily boosts your front line immune defenses but prolonged or chronic stress has the opposite effect. During the acute “fight or flight” stress response set off by adrenaline (going to the dentist, a near collision) more white blood cells are sent to your front lines to help reduce the chance of infection from an injury sustained in the “fight or flight”. They quickly return to normal once the stress has passed.
However, the elevated cortisol produced during prolonged or chronic stress (a long illness, an unhappy relationship) suppresses the deeper, adaptive aspects of immunity that protect you over the long term from disease. This stress-related overall decrease in immune function combined with its long-term detrimental effects on your other defenses can leave you more susceptible to colds, flu and other infections, and potentially make you more vulnerable to serious illness and degenerative disease down the road. And because chronic stress also tends to increase inflammation, it can also make you more prone to the development of allergies and autoimmune disorders. Managing your stress, promoting strong immune function and healthy microbial balance in your body’s front-lines can significantly enhance your ability to stay well.* [return to top]
Your body and brain depend on balanced levels of blood sugar (glucose) to steadily supply your cells with fuel for energy. Stress normally drives blood sugar up to power a “fight or flight” physical response via the adrenal stress hormone cortisol. Cortisol converts energy stored in your body into glucose so that your blood sugar rises to energize that anticipated surge in activity. As your blood sugar goes up, insulin is secreted by your pancreas to move the glucose from your blood into your cells. This extra glucose is meant to be used up by a strenuous physical response to the stress, which restores blood sugar back to normal.
In the prehistoric world, stress typically came from physical threats against which a short burst of activity increased the odds of survival. However, in the modern world stressors are typically ongoing pressures against which physical activity is seldom used or useful. If your life is stressful, especially with a diet high in refined carbohydrates and without regular vigorous exercise, the consequent repeated or chronic blood sugar and insulin elevation you experience can create problems over time that prehistoric humans probably never had to face. When this occurs too frequently, your cells become more resistant to insulin to avoid the toxicity of excess glucose.
This can leave too much glucose in your blood and too little in your cells. To maintain balance, your body converts and stores the excess blood sugar as fat – usually around your abdomen. Paradoxically the decreased amount of glucose getting into your cells triggers hunger and you may find yourself craving carbohydrates. Refined carbohydrate consumption creates a spike in blood sugar, and the vicious cycle of blood sugar imbalance and insulin resistance continues – an added stress with even greater negative consequences for your whole body over time. When it comes to blood sugar, maintaining balance is the key for good health and steady energy. [return to top]
Your stress response gives you an immediate energy boost so you can physically deal with the stressor (“fight or flight” response). In the prehistoric world, stressors were typically physical threats against which a short term burst of energy increased the odds of survival. In the modern world, stressors are typically ongoing pressures against which sustained energy is required just to keep pace. Throw in some short term stresses, like vigorous exercise, an argument or a traffic jam, and your stress response system has to work even harder.
Your adrenal glands work the hardest to respond to stress and are the primary glands to lead in stress and energy recovery. One of their key functions is to release energy stored in your body so that blood sugar rises to meet the increased demand for energy during stress. In stressful times the adrenals can become fatigued, affecting many aspects of health, including energy levels.*
The low energy feeling following a workout, illness or other stressful event is typically due to temporarily lowered adrenal function, and as the adrenals gain power after the stress, the fatigue and lethargy lessens. People experiencing ongoing adrenal fatigue typically notice that their energy is low, particularly in the morning and midafternoon, and that they feel more depleted than usual by exercise and have less stamina.* This typical adrenal fatigue low energy pattern can be worsened by additional stress – even enjoyable stress like exercise or sex – because the adrenal glands play such an important role in generating energy.*
During adrenal fatigue, it can be more difficult for your adrenals to meet this demand for increased energy, with the result that your already low energy takes a further dip.* The combination of adrenal fatigue with the low blood sugar that normally occurs first thing in the morning and between meals midmorning and midafternoon can make these the lowest energy points in your day. Many people turn to caffeine and sugar to get them through these times. However, the quick energy bump caffeine and sugar provide has its downside because caffeine drives the adrenals, leaving them even more depleted over time; and sugary foods can make blood sugar spike and then drop even lower.
To enhance energy at these times of day without further draining your adrenals and disrupting blood sugar balance, it can help to provide the nutrients necessary for optimal adrenal function, plus energy support.* Whether your low energy is temporary after exercise or a stressful event, or is prolonged by chronic stress, this approach is more likely to help you bounce back faster and maintain the energy to keep up all day.* [return to top]
Your body is always working to maintain homeostasis (homeo = the same, stasis = staying) in a constantly changing, stressful environment because your survival depends on it. Life can only exist within a narrow range of conditions – imagine how you would feel without water for several days, or with a 106°+ temperature, skyrocketing blood pressure or plummeting blood sugar. Homeostatic control provides the internal stability necessary for life. Stress disrupts that stability.
Your ability to respond and adapt to stress is therefore a fundamental aspect of the continuous balancing act that is homeostatic control. This control is accomplished through complex feedback loops that communicate every tiny change in your body between your nervous system, brain and endocrine (hormone producing) glands. Your brain assesses and responds to the information provided about your internal state by your nervous and endocrine systems. Your endocrine glands produce exact amounts of hormones in response to instructions from your brain.
These hormones act as the agents of change that tell every cell what to do. Central to your stress response is the feedback loop called the hypothalamic-pituitary-adrenal (HPA) axis consisting of your hypothalamus (a regulatory part of your brain), pituitary gland (your master endocrine gland), and adrenal glands (your main glands of stress, producing over 50 hormones affecting nearly every cell in your body and brain). Because homeostasis is essential to life, anytime you get too far from optimal – either too much or too little response to stress, it’s not surprising you feel bad.
Think of the symptoms of a panic attack (pounding heart, rapid pulse, flushing, hyper-vigilant fear) as an extreme over-response to acute stress, and medical shock (low blood pressure, weak pulse, cold skin, dissociated confusion) as an extreme under-response. The symptoms of both are largely due to HPA axis responsiveness and consequent adrenal hormone levels, which influence things like blood pressure, heart rate, blood sugar and mental focus. In a chronically stressful life, the internal balancing act of homeostasis gets a lot harder.
For example, prolonged HPA axis over-responsiveness can lead to persistent high blood pressure, high blood sugar, agitation, inability to relax and ensuing conditions like metabolic syndrome. Prolonged HPA axis under-responsiveness can lead to persistent low blood pressure, low blood sugar, low energy, generalized disinterest in life and consequent conditions like adrenal fatigue. If your adrenal glands become fatigued, it may be almost impossible to feel balanced because adrenal hormones play such a key role in your capacity to maintain homeostasis in stressful situations. It’s not difficult to see that balanced regulation of HPA axis function is critical to your ability to adapt to stress in ways that maintain optimal homeostasis and allow you to feel balanced, especially in a stressful world. [return to top]
A stressful life can be hard on your hair, skin and nails, and also on healing speed after an injury. During stress, your body’s survival priority is to prepare you to physically respond to the stressor (the “fight or flight response”). This means growth, maintenance and repair of tissues gets temporarily downgraded to a lower priority.
Simultaneously, several things happen in your body that decrease the availability of the resources needed for cellular growth. All the building blocks to repair and create healthy tissues come from the nutrients you digest and absorb. Stress hormones slow digestion, decreasing secretion of digestive enzymes and diverting blood away from your digestive system, which impairs nutrient absorption.
Available nutrients, oxygen and fuel are sent to your muscles first, leaving your cells with less of what they need for tissue growth and repair. Making matters worse, when you are under stress, your body burns through nutrients faster than normal and may deplete some nutrients, like biotin, that are essential for healthy tissue formation. When stress is a brief occurrence, your body quickly adapts and returns to normal.
However, when stress is frequent, prolonged or chronic, healing and rapidly growing tissues like hair, skin and nails are hit the hardest. For example, shiny hair, strong nails and tissue healing require minerals, but under stress, the demand for certain minerals such as magnesium and manganese increases while nutrient absorption and assimilation decreases. Deficiencies can show up as dull, brittle hair and shredding, ridged nails.
In someone with adrenal fatigue, absorption of these minerals and other essential nutrients is even more difficult, making the combination of high stress with adrenal fatigue particularly detrimental to tissue health. In addition to the reduced availability of nutrients, there are several aspects of stress that can actually damage tissues over time, including excessive cortisol (a stress hormone), accelerated free radical production, and elevated blood sugar and insulin. For example, skin normally has a fatty layer which protects and insulates it, retains moisture, and gives it a smooth softness.
Excessive cortisol damages this layer, resulting in thin, fragile skin prone to easy bruising, stretch marks, and infection. When free radicals are generated faster than your cells’ antioxidant mechanisms can neutralize them, they damage your cells and their DNA, interfere with the protein that keeps your skin firm and prevents sagging, hasten the formation of wrinkles, and speed up the aging process.
Conversely, if your adrenal glands become depleted by chronic stress (as in adrenal fatigue), they may not be able to maintain adequate cortisol levels to sufficiently sustain energy and stimulate nutrient metabolism for optimal tissue growth, repair and protection. With both high adrenal function and adrenal fatigue, a stressful life can be detrimental to your ability to grow healthy new tissues. Managing your stress and making sure you get the daily nutrients necessary for cellular growth and repair can make a positive difference to how you look and how quickly you heal. [return to top]
Stress has multiple effects on your digestive tract that when prolonged or chronic can disrupt healthy gut integrity, leading to problems ranging from cramping and discomfort to allergies and autoimmune disease. Gut integrity is responsible for proper barrier function, i.e. acting as a filter that allows nutrients to pass through your intestinal walls into your bloodstream while retaining toxins, undigested proteins and other harmful substances for elimination.
This healthy barrier function depends on the thin, slippery membrane (mucosa) lining your stomach and intestines. The mucosa is larger than a football field when spread out and creates a protective layer that shields the walls of your digestive tract from becoming inflamed or damaged by the acidic, alkaline and toxic substances involved in digestion. Plus, it is also the site of intense immune activity to protect the underlying tissues and the rest of your body from harmful foreign invaders. The mucosa requires rapid new cell growth to replace itself every few days and stay healthy. However, stress cuts back on new cell growth throughout your body, allowing the mucosa to become thinner and damaged over time.
Because stress also slows digestion, alters gut flora and increases gut permeability, toxic substances remain longer in your intestinal tract while harmful bacteria tend to multiply and crowd out the beneficial bacteria normally present. This creates increased irritation and inflammation of the walls of your digestive tract, adversely affects immune function and allows more toxins to be absorbed into your body. If the ongoing stress fatigues your adrenal glands, your digestive system is slower to return to a pre-stress level of building, maintenance and repair at the same time your body’s main anti-inflammatory, the adrenal hormone cortisol, is low.
The delicate tissues of your stomach and intestinal tract are then even more vulnerable to inflammation and damage, and subsequent reduced barrier function. It is therefore not surprising that chronic or prolonged stress can adversely affect the integrity of your gut, resulting in digestive system distress and more serious problems over time. Managing your stress and keeping the lining of your digestive tract in good shape is essential for optimal gut integrity and comfort, proper nutrient absorption, ease of digestion, good bowel function, elimination of toxins, resistance to germs, avoidance of food reactions and allergens, and your overall good health. [return to top]
Stress triggers multiple changes in your digestive system with the overall effect of slowing it down. As your body shifts energy and resources into the “fight or flight” stress response, maintenance activities like digestion are put on the back burner. It makes sense if you consider that when you hear footsteps behind you in a dark alley at night, you would probably rather have your running muscles fueled up than your pizza digested in that moment.
This redistribution of energy and resources in your body works well for short-term stresses in which digestion can quickly return to normal once the stress has passed. However, prolonged or chronic stress can mess up your digestive system in a variety of ways related to the effect over time of the many changes stress produces.
Among other things, stress reduces secretions of saliva and the protective mucus that coats your digestive tract; decreases the quality of digestive juices like stomach acid and enzymes that break down proteins, carbohydrates and fats; disrupts muscle contractions, creating cramping, diarrhea or constipation; slows stomach motility and peristalsis, allowing food and toxins to remain longer in your system; shunts blood away from your digestive tract, reducing nutrient absorption; alters the bacterial balance in your gut, potentially allowing harmful bacteria to multiply; increases gut permeability, creating an environment that allows more toxins and allergens to be absorbed into your body; and boosts proinflammatory immune activity along your digestive tract.
Just from this list you can see why a stressful life likely includes some digestive problems. To make matters worse, it is easy to disregard healthy habits when stressed. Routinely working through lunch or eating on the run does not give your relaxation response a chance to even become activated! If your adrenals fatigue from prolonged stress, digestion can suffer at the same time that food cravings increase because of low blood sugar, and digestive tract inflammation flares from the combined effects of slower digestion and decreased anti-inflammatory activity by cortisol.
Managing your stress, eating regular meals consisting primarily of whole foods, relaxing while you eat, getting enough fiber, drinking enough water and supporting healthy microbial balance in your gut can help your digestive system function optimally. [return to top]
Your thyroid gland plays an integral role in your body’s ability to adapt to stress and, like your adrenal glands, has to work harder during stressful times. Primarily through the profound influence of the adrenal stress hormone cortisol on thyroid hormones, thyroid function is greatly affected by stress and the activity of the stress response system (hypothalamic-pituitary-adrenal axis). Your thyroid gland combines iodine and the amino acid tyrosine to make two major hormones, thyroxine(T4) and triiodothyronine (T3), which regulate metabolic rate (the speed of energy production and utilization in your cells). For example, T3 and T4 regulate your heart rate and intestinal peristalsis, so if they are are low, your heart rate may be slower than normal, and you may experience constipation: If they are high, you may experience rapid heart rate and diarrhea.
During gestation, infancy and childhood, adequate thyroid hormone is also crucial for proper growth and brain development. T3 is much more active than T4 and every cell in your body responds to it. Cortisol is necessary to make your cells receptive to T3 and for conversion of the relatively inactive T4 to T3. For these reasons, it is possible to experience low thyroid (hypothyroid) signs and symptoms because your cortisol is low, even when your thyroid is functioning normally. In fact, many people suffering from low thyroid also have low adrenal function (adrenal fatigue).
When adrenal function is low, thyroid medication may be ineffective until adequate adrenal function (and cortisol) is restored. On the other hand, too much cortisol can also result in lowered thyroid function. High cortisol and other factors released during stress can reduce T4 and T3 production by limiting pituitary production of the hormone (thyroid stimulating hormone) that signals your thyroid gland to make more T4 and T3. Excess cortisol can also inhibit the conversion of T4 to T3, and cause T3 to turn into reverse T3, which is an inactive form that blocks the T3 receptors in your cells. This stress induced reduction in T3 and increase in reverse T3 in your cells results in tissue hypothyroidism that is not detected in standard thyroid function lab tests but can potentially produce weight gain, fatigue, depression and other symptoms of low thyroid.Treatment with prednisone or other glucocorticoid drugs (substances that mimic cortisol) has a similar suppressive effect on thyroid function.
Some of the other factors that may lead to a preferential conversion of T3 to reverse T3 include deficiencies in iodine, selenium, zinc, copper, iron, and vitamins A, B, C and E, which all play crucial roles in the production and maintenance of thyroid hormones. Stress is also one of the environmental factors that increase vulnerability to thyroid autoimmunity (e.g. Hashimoto’s thyroiditis). From even just this brief outline of some of the effects of stress on thyroid function, it is easy to see the importance to optimal thyroid function of managing your stress, and supporting both thyroid and adrenal health, especially if your life is stressful or you have experienced severe, prolonged or chronic stress. [return to top]