The Digestion and Stress Connection
In the past few years, the “mind-gut connection” has become such a topic of conversation, that I feel it’s simple yet powerful message has been lost. That being, we now have proof that the brain and digestive tract are connected. And this is due to the fact that the small intestine has its own nervous system, and is in constant communication with the brain.
Why does the digestive tract have it’s own nervous system?
Approximately 600 million years ago, early multicellular organisms (Hydra’s) consisted primarily of a digestive tube surrounded by a nerve net. This early nervous system could be considered the first brain, as it’s duty was to regulate the movement of food and extraction of nutrients. As evolution progressed this “gut” was largely preserved during the development of a second brain (the brain/central nervous system we currently recognize). Signaling molecules developed in this first brain, were incorporated in the new brain creating the communication between the “mind-gut” that exists in both the animals and humans of today.
Source: Mayer, E. (2021) The Gut-Immune Connection, pp. 67-70.
How is the brain involved in digestion?
The moment we think of, smell, or see food, the brain has begun the digestive process. This involves a series of messages that secrete enzymes, release hormones, and move muscles from the mouth, esophagus, stomach, small intestine, liver, gallbladder, pancreas, large intestine, and finally the rectum.
However this well designed system can only take place when we are relaxed, and in the often referred to “rest and digest” state. This is because the brain is constantly monitoring how safe things are both internally and externally. And when there are any senses of alarm, survival mode kicks in switching “rest and digest” into “fight of flight”.
These two states are actually separate networks of nerves known as the parasympathetic nervous system (“rest and digest”), and the sympathetic nervous system (“fight or flight”). They have historically existed to protect us from occasional dangers such as predators. Sadly, in modern day they are triggered by smaller threats that happen far more frequently such as emails, traffic, and the overabundance of responsibilities causing what we refer to as stress.
How does stress affect digestion?
When we aren’t relaxed, and find ourselves in “fight or flight”, our brain has put the sympathetic nervous system into effect. This inhibits digestion, increases lung capacity, accelerates heart rate, stimulates adrenaline, and diverts blood flow to muscles in the arms and legs, preparing us to drop everything and run, i.e. escape danger.
The issue is that this danger our brain is planning an escape from is typically happening throughout the day, and instead of running (or resolving), we often choose to ignore the stressor leaving us in this altered state. Without our knowing it, the series of messages from the brain to each digestive organ are put on pause for extended periods of time leading to uncomfortable symptoms such as acid reflux, constipation, diarrhea, bloating, and gas.
How does digestion affect stress?
Unfortunately, when stress patterns begin to present themselves, they are often followed by digestive issues on a repeated basis. These symptoms of indigestion can be bothersome, but also quite uncomfortable and the more frequently they take place, the more overwhelming they can become.
This is when digestion can cause stress because as the symptoms of the issue appear, a series of internal alarms (pain, nausea, etc) alert the brain that danger is present. The brain then decides this danger, or stress, can be easily averted by resuming “fight or flight” and shuts down digestion. Thus creating a cycle of digestion causing stress, causing (in)digestion causing more stress.
What can be done to prevent digestive issues?
We can’t always change the stressful situations we find ourselves in, but we can change the way we approach them. Here are a few simple steps that can be taken to put us back into “rest and digest”:
Pause work, or responsibility for the duration of a meal
Take 3 deep inhales and exhales before starting eating
Be present by focusing on the food, flavor, and texture
Enjoy the experience, and know that things can improve
If you have questions as to how we can work on the issues you’re experiencing,
contact me so that you can