Cortisol and Your Gut
The image of stress-induced ulcers has been with us for decades. You've probably seen, on a TV sitcom or other such venue, the stereotypical portrayal of the stressed-out executive. Deadlines loom, stress builds, and the businessman gulps down antacids to quell the burning ulcer in his stomach. Far from being one of the many Hollywood overexaggerations, the phenomenon of stress-induced ulcers and other digestive problems has been documented in the medical literature for more than fifty years. From a physiological point of view, we know quite clearly that any stressful event will cause digestion to cease. Blood flow is diverted from the digestive organs to the heart and muscles, secretion of saliva and digestive enzymes is slowed, and intestinal contractions and absorption of nutrients stop. This rapid shutdown of the digestive process makes perfect sense, because from the standpoint of long-term survival it is more important to get away from the dangerous stressor (the lion) than to fully digest all your food. There will be plenty of time for digestion later; right now you need to save your skin. It is interesting to note, however, that even while stress hormones are signaling the body to shut down digestion, these same hormones, when kept elevated for more than a few minutes, are telling us to eat—and eat a lot!
Medical evidence shows quite clearly that ulcers of the stomach (gastric ulcers) and intestine (duodenal ulcers) are much more common in people who are anxious, depressed, or under chronic or repeated stress. In these situations, which are all examples of chronic stressorsIn the face of these conditions, which are all also examples of chronic stressors, many of the digestive actions are curtailed, andso the body also backs off from its production of other protective measures—such as the mucus that lines the stomach, and the bicarbonate that counteracts the highly acidic gastric juices. Sounds logical, right? And it is. Why should the body take a lot of protective measures against acid that will never be secreted (because you're under stress)? The problems start to occur when a person experiences the repeated cycles of high stress followed by low/normal stress that have become commonplace in our modern society. This sets up the digestive system for total confusion. Most of the time the body won't be able to secrete enough digestive enzymes to properly digest food (producing nausea, constipation, gas, and bloating). During the "lucky" times when a body can secrete enough digestive enzymes to properly break down food, the protective mechanisms are far from fully operational—which puts a person at risk for damage to her gastrointestinal tract (because the enzymes digest the gut's lining in addition to digesting the food). This scenario says a lot about why several bouts of intense stress are known to cause more ulcers than a longer continuous period of heightened stress.
To compound the problem, other factors, such as immune-system function and the body's control of inflammation and wound healing, come into play. It is well described in the medical literature that both repeated periods of acute stress and continuous periods of chronic stress are associated with suppressed immune-system activity. This has a direct bearing on ulcer development, because less immune-system activity means more growth and higher activity of a bacterium called Helicobacter pylori, which infects the stomach and causes ulcers in 80 percent of the people infected with it. Compounding the tissue damage caused by the accelerated growth of H. pylori is a suppression of the body's ability to heal that tissue damage because of an inhibition in prostaglandin synthesis. Prostaglandins are typically produced in response to tissue damage, where they help reduce inflammation and accelerate healing. During times of stress, however, the synthesis of prostaglandins is curtailed, which suggests that stress not only increases the rate at which ulcers may form, but also slows the rate at which they are repaired.
Aside from ulcers, the most common stress-related gut disease may be irritable bowel syndrome (IBS). Most of us will experience some degree of IBS during our lifetime. The name "IBS" is really a catchall for a variety of intestinal disorders, including colitis (inflammation of the lining of the large intestine, also known as the colon), in which abdominal pain is accompanied by diarrhea and/or constipation, bloating, gas, and, occasionally, passing of mucus or blood. The majority of the gastrointestinal conditions falling under the IBS umbrella are either caused by or exacerbated by periods of heightened stress. Irish researchers have solidified the link between stress, inflammation, and gastrointestinal diseases such as IBS through a series of experiments involving 151 subjects that showed IBS to be clearly exacerbated by stressful psychological events, with cortisol and inflammatory cytokines such as IL-6 and IL-8 elevated in all forms of IBS (that is, IBS with diarrhea, IBS with constipation, and IBS with both).
So, again, we have bad news about stress and cortisol for an important bodily system. Stress leads to poor digestion, ulcerated stomachs, and inflamed intestines—not a pretty picture. These effects tend to result in poor dietary choices, suboptimal nutritional status, and a drop in energy levels and overall feelings of well-being. Getting stress and cortisol levels under control can help to reverse these problems.