Stress and Your Digestive System
Any stress you experience, be it physical or emotional, activates the sympathetic nervous system and triggers production of adrenal hormones, such as adrenaline and cortisol, that prepare your body to deal with the stress. This is often called the “fight or flight” response because, metabolically, the body becomes primed for one of two physical reactions: to run or to fight. Under the control of cortisol, adrenaline and the sympathetic nervous system, the body’s focus shifts from maintenance mode to emergency preparedness. This shift causes a number of effects on the digestive system:
• Secretions are reduced, including saliva, digestive enzymes and protective mucus
• Blood is shunted from the digestive organs to the skeletal muscles, reducing nutrient exchange
• Nutrient absorption is diminished
• Muscular contractions in the intestines become irregular and can create cramping, constipation or diarrhea
• Sphincters close, inhibiting normal movement of food through the tract
• Peristalsis slows, allowing toxins to remain longer in the colon and harmful bacteria to multiply and crowd out the beneficial bacteria normally present in the gut
• Over time the lining of the stomach and intestines can become thin and damaged, creating an environment that allows more toxins to be absorbed into the body
• Immunity in the digestive tract is impaired with these changes
When 21st Century Stress Takes Over
Throughout human evolution, adrenal hormones and the sympathetic nervous system have suppressed digestive function during the stress response. Historically, the digestive system handled these fluctuations with relative ease. Now, though, stress-related digestive disorders like nervous stomach, constipation, diarrhea, irritable bowel and ulcers have become all too common. The stress response is the same as it has always been, but 21st century stress is dramatically different.
Your stress response is designed to prepare you to physically deal with stress (running from a lion, for example), and the physical exertion helps dissipate stress hormones, quickly moving your body back into balance. However, modern stressors rarely require a physical response, and they tend to last longer and be more pervasive. For example, difficult relationships, unemployment, unsatisfying work, debts and mortgages affect your daily life and may last for months or years. Because you cannot fight with a loan or outrun a job, your stress hormones are not easily dissipated, and because the stressors do not go away, your brain keeps signaling your adrenals to make cortisol. As a result, digestion continues to be curtailed, with unhealthy consequences. To make matters worse, it is easy to disregard healthy habits when stressed. You may find yourself downing caffeine to keep going or drinking alcohol to calm down, both of which can damage your digestive tract lining even more. Sugary comfort foods contain very few nutrients, and sugar actually robs your body of B vitamins and other nutrients, pushing your nutritional status even lower. Routinely working through lunch or eating on the run does not give your parasympathetic nervous system (the 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.