Stressed-out shoppers may exhibit overworked symptoms by way of a terrible feeling in their guts. It’s not only in their heads, as a scientist explained the “brain-gut axis," a part of the nervous system, can cause this reaction to stress. The August 2010 issue of the Harvard Mental Health Letter includes an article by Dr. Michael Miller, who explains this connection.
He wrote the brain interacts with the rest of the body through the nervous system, which has several major components. One of them is the enteric nervous system, which helps regulate digestion. The “fight or flight" response many of us are all too familiar with slows digestion, or even stops it completely, so the body can focus all of its internal energy to facing the threat. The sympathetic nervous system triggers the "fight or flight" response, he wrote, while the parasympathetic nervous system calms the body down after the danger has passed. Both the sympathetic and parasympathetic nervous systems interact with the enteric nervous system, which helps regulate digestion.
The enteric nervous system is sometimes referred to as a "second brain" because it relies on the same types of neurons and neurotransmitters that are found in the central nervous system (brain and spinal cord).
Studies have show stress, such as an argument, public speaking or driving in traffic, also can slow or disrupt the digestive process, causing abdominal pain and other gastrointestinal (GI) symptoms. Then, again, he added, it can work the other way as well: persistent GI problems can heighten anxiety and stress.
Functional GI disorders affect 35 percent to 70 percent of people, he wrote noting women suffer from them more than men. While these disorders have no apparent physical cause, the root of the problem is usually biological, psychological and social factors.