By Jonathan Cerna, BS Dietetics, MS Student In Nutritional Sciences and Dietetic Intern
There is a famous Zen Buddhist saying which I say to my friends often: “The way you do anything is the way you do everything”. This quote is salient and relevant because, effectively, our mental habits reassert themselves and often spill over into our normal daily activities, which includes the times when we eat. How often do you find yourself in this scenario: you are having dinner while looking at your phone or watching TV. Before you know it, you finish your meal. But you remember little about what your meal smelled and tasted like. Then you say to yourself, almost as a question, “it was pretty good?” We have all been there. What is missing here is mindfulness. Did you know mindful eating can promote digestive health? Although many articles are written about mindful eating and its salubrious subjective health effects before, during, and after our meals, little emphasis is given on how the psychological effects induced by mindfulness training can have lasting effects that synergize with the physiological changes that promote better digestive health. An article published in the journal of Integrative Medicine tells us in detail how mindfulness, when applied to eating, can benefit our digestive health. You will learn the reasons why next time you might want to turn off the TV and put down your phone when you enjoy your dinner.
First comes first, what is mindfulness? The word “mindfulness” is currently in vogue, but not everyone can provide a basic and accurate definition of it. I speak from experience, of course. At the beginning of my personal journey on exploring mindfulness, I made every mistake about what this practice actually entailed. After several silent meditation retreats, hours after hours in the seating cushion, and reading books and scientific literature, I realized I had no idea what I was initially getting into. Few people understand why the practice is not really about sitting with legs crossed, or even about inducing any kind of state-effect like bliss, peace, or rapture. Personally, I define mindfulness as training in well-being. Mindfulness cultivates various types of attention, love for self and others, a non-judgemental attitude, and other meta-cognitive skills (not only awareness of the skill being trained but awareness of awareness itself). Repeatedly inducing these states produces trait-effects (long-lasting, intrinsic qualities of our personality) which include equanimity, accurate discernment, lasting compassion and empathy, or simply stated, wisdom. This development is tightly associated with affect regulation, social-emotional learning, and executive function (higher-order cognitive function such as impulse inhibition, selective and sustained attention, working memory, etc.). So, what is the connection between these skills and positive changes in digestive function?
Mindful eating takes the metacognitive skills established during mindfulness training and applies them to feeding behaviors. More specifically, one is asked to maintain keen attention and a non-judgmental attitude before, during, and after eating. If successfully implemented, this elicits a psychophysiological change that shifts the activation in our nervous system from “fight, flight or freeze” commonly associated with activation of the sympathetic nervous system (SNS) to the “rest, relax and digest” parasympathetic nervous system (PSNS). These changes are important because they match the changes in gastrointestinal (GI) physiology which aid in proper digestion and absorption of various dietary components. For instance, inducing PSNS dominance while eating is known to positively impact our enteric nervous system (ENS), colloquially called our “gut-brain” or our “second brain”. ENS encompasses everything from the esophagus to the rectum. Positive changes occur in motility, blood flow to the GI tract, inflammation, vagus nerve activity, and even serotonin production. They are detailed in the figure below:
What explains these positive changes? Broadly speaking, we know that everyone undergoes various types of stress which can be encapsulated under the following conditions: acute or chronic, eustress, or distress. When we are exposed to a manageable stressor that we can overcome either now or over time, we call that “neutral or positive stress”, commonly associated with eustress. On the other hand, when our stress load significantly increases but still falls into the “manageable” category, we call it a hormetic stressor. Simply speaking, hormesis refers to the concept of a “goldilocks zone” of exposure, where a sufficient dose provides benefits, but an overdose results in diminishing returns. Relatedly, a “fight or flight” reaction causes a whole-body response which has wide-spread consequences in our GI tract. Examples of this include:
- Increased gut-permeability, often called “leaky gut” (related to many problems including a heightened inflammatory burden, common in Celiac Disease)
- Diverted blood flow away from the gut (nutritional resources are shunted away from the gut to our peripheral muscles for immediate use).
Acutely, this can be immensely beneficial (i.e., you would not want to be chillaxing while a building is falling close to you), but chronically this is immensely problematic. That is because our body needs to come back to baseline. In other words, a continual state of emergency is all-around problematic. Even more problematic, our nervous system is sensitized to all stressors, not just physical (such as stress exertion), but chemical (various drugs, and pollutants), mental (anxiety and worry), and emotional (anger, fear, and sadness among other afflictive emotions). As stated in the published review, “stress is the juncture at which mindfulness can be narrowed into the construct of mindful eating. This vantage point illuminates the role of mindful eating in optimizing digestive function”. With this in mind, it is undeniable that learning how to come back to baseline on command is a skill that is in dire need in this society.
Peer-edited by Ru Liu, MS, RD