How Digestion Impacts the Body’s Systems
As a Nutritional Therapy Practitioner, having my clients begin by first addressing the foundations for optimal health is at the core of my practice. This is a foolproof way to uncover and address the root cause of an imbalance in the body. More often than not, our most debilitating symptoms can be addressed by simply taking it back to the basics.
In nutritional therapy, we refer to many of the body's systems as "consequences" meaning an imbalance in the following systems is likely due to improperly functioning foundations. So, if you don't first address the foundations (diet, digestion, blood sugar regulation, fatty acids, mineral balance and hydration), you will likely have an imbalance in the following systems:
Endocrine System
Immune System
Cardiovascular System
Detoxification System
Nervous System
To learn more about addressing the six foundations in more detail, you can check out my earlier blog post. But if you're experiencing dysfunction in any of the aforementioned systems and looking for a place to start, I always recommend addressing your digestive system first.
The Endocrine System
You’ve likely heard of the endocrine system, but what exactly does it mean? The endocrine system is made up of glands that make hormones, which are our body’s chemical messengers. Hormones regulate everything from metabolism and energy balance to sleep-wake cycles, immune activities, growth and development, and the reproductive system.
When it comes to addressing issues with the endocrine system, there are three big ideas to keep in mind. First, the endocrine system is one of complex relationships. We must always support the whole as well as the parts. Second, each client’s endocrine system is bio-individual, meaning what works for one client might not work for another client. And third, we must always address the Foundations first (Nutritional Therapy Association, 2023).
Any attempt to normalize hormonal imbalance is futile until digestion is addressed. Without properly functioning digestion, our bodies cannot make the hormones we need for optimal endocrine health. Let’s take a deeper look at some of these.
Steroid hormones are derived from cholesterol meaning we need to consume and be able to properly digest good quality fats in our diet.
Thyroid hormones require foods with high-quality proteins and iodine. To make amine hormones, peptide and protein hormones, we need to consume and be able to digest quality proteins.
Eicosanoid hormones, which help us properly manage inflammation, require the consumption and digestion of good healthy fats.
If your digestion is struggling, you can’t break down the peptides into individual amino acids, therefore you won’t be able to make peptide or amine hormones. And the healthy fatty acids you’re consuming mean nothing if gallbladder function isn’t optimal, because without a healthy gallbladder, fats cannot be broken down into hormones to manage inflammation.
By now you should start to be able to see why we want to start with the Foundation of digestion. It’s easy to want to spot treat hormonal symptoms, and so many people opt for a supplement or even hormone replacement therapy, but without addressing digestion first, you’re simply treating your symptoms and not the root cause. By doing so, the issue is likely to continue arising.
The Immune System
The immune system includes three main sub-systems: the integumentary system, the lymphatic system, and the digestive system. You may have heard that your immune system starts in the gut, and this is absolutely true! Between 70 and 80% of all immune cells live in the gut-associated lymphoid tissue (Nutritional Therapy Association, 2022). It goes without saying that healthy digestion is critical to healthy immune function, so supporting the north-to-south digestive process, like with the other consequences, is key to supporting the immune system.
But why exactly? Let’s break it down by the different digestive organs, beginning in the stomach. Optimal HCL production in the stomach ensures food is properly disinfected and broken down. Moving on to two accessory organs, healthy liver and gallbladder function are critical to producing complement proteins (which destroy invaders), energy production, and the elimination of immune products and waste materials. A healthy small intestine with a healthy mucosal lining ensures tight cellular junctions, which prevents leaky gut syndrome. This is when foods not broken down slip through the permeable lining of the small intestine into the bloodstream. The immune system recognizes these food particles as invaders which elicits an immune response in the form of food intolerances. In the large intestine, healthy gut flora helps stimulate the immune system by feeding the epithelial cells and crowding out pathogenic bacteria as well as facilitating nutrient digestion and assimilation (Nutritional Therapy Association, 2022).
Simply not chewing your food enough or eating in a stressed or distracted state really can affect your immune system’s function! So before you pop those immune boosting supplements, first start by taking some deep breaths and relaxing before mealtime.
The Cardiovascular System
As with the other systems of the body we’ve discussed, a healthy heart depends on a healthy body, so as always, we’re going to address the foundations first. Hypertension is one of the strongest risk factors for cardiovascular disease, but by addressing the digestion first, we can oftentimes prevent and reverse signs of hypertension and cardiovascular disease in the first place.
While many of us have been told that the key to having low cholesterol is to consume less cholesterol-rich foods, this is in fact not the case. In most people (about 75% of the population), dietary cholesterol does not significantly affect blood cholesterol (Djoussé & Gaziano, 2009). In fact, cholesterol is quite important for various functions in the body including building and maintaining membranes, modulating membrane fluidity, making bile, and serving as a precursor to all steroid hormones as well as Vitamin D. But in order to properly utilize cholesterol, we must have optimal digestion.
Digestion is critical for preventing hypertension and heart disease. To begin, good protein digestion is critical to making available the amino acids needed by the heart, such as taurine and carnitine. Proper stomach pH is also needed to absorb calcium and digest B vitamins, both of which play a critical role in preventing heart disease. Additionally, proper liver/gallbladder function enables the digestion of healthy fats as well as fat-soluble vitamins. And lastly, proper bowel flora is needed to produce B and K vitamins, which play a great role in cardiovascular health (Nutritional Therapy Association, 2023).
The Detoxification System
The word detox is oftentimes associated with juice cleanses, fasts, and restricted diets. Especially as we move into a new year, it will be hard to avoid the advertisements for these "detoxes" which are often marketed as a quick fix to cleanse and detoxify the body. But the truth is, when the body is functioning optimally, detoxification is a naturally occurring process that doesn't require a magic pill or juice cleanse.
Detoxification is the way the body heals and repairs itself – it is an internal cleaning process that takes place continuously and naturally. In fact, these "detoxes" that are marketed to us can actually be quite harmful, particularly if we have not yet addressed our foundations. Just like the other consequences we've talked about so far, proper detoxification is dependent on optimally functioning digestion.
The digestive system is heavily involved in the body's detoxification process, making the process much more seamless when functioning optimally. The digestive system scans food for invaders, detoxifies any poorly digested food, filters food and intestinal bacteria, and eliminates toxins and other unusable substances from the body. This is accomplished by our intestines which contain probiotic bacteria that assist in the detoxification of substances; by our liver which filters toxins from the blood and neutralizes them in preparation for elimination; and the gallbladder, which give the toxins an exit pathway of bile, which is eventually excreted as feces (Nutritional Therapy Association, 2023).
If a person isn’t digesting properly, even the most perfect diet can clog the body’s detoxification pathways. For example, poor fat digestion will clog the lymph, and therefore the liver. This is because the bile, which is produced by the liver and stored in the gallbladder, is the river by which toxins are removed from the body through the intestinal tract. So without adequate bile secretion, the lymph gets clogged and toxins remain stagnant in the body. Additionally, without proper stomach acid to break down dietary protein into amino acids, the body will be void of the essential amino acids needed for the proper functioning of the detox pathways in the liver, such as methionine.
Lastly, if digestion is impaired, elimination is likely impaired as well, therefore, a detox or cleanse of any sort should be avoided until this is addressed. Without open exit routes for toxins, you risk stirring them up in the body with nowhere to go, leading to unpleasant side effects and ultimately reabsorption of the toxins.
The Nervous System
Last but not least is the nervous system. We know by now what an important role the nervous system plays in digestion, particularly the parasympathetic nervous system. You can read more in my earlier post about the importance of being in a rest and digest, parasympathetic state for optimal digestion.
But we're now learning more about how digestion can support the healthy function of the nervous system as well, particularly the enteric nervous system. You've likely heard the expression, "go with your gut," or the idea of a "gut feeling." Well research shows that this is for good reason. The enteric nervous system is a system of neurons that governs the function of the GI tract, also known as the gut-brain connection. It consists of two thin layers of more than 100 million nerve cells lining the GI tract from the esophagus to the rectum.
The main role of the enteric nervous system, or "second brain" as some call it, is to control digestion, and regulate muscle function, immune cells, and hormones. Additionally, it manufactures an estimated 80 to 90 percent of serotonin, which is our "feel good" neurotransmitter (Perlmutter, 2015). This is a huge factor in understanding how our digestion affects our mental health.
According to a Clapp et. al (2017), dysbiosis and inflammation of the gut have been linked to causing several mental illnesses including anxiety and depression. The study also showed that by restoring normal microbial balance, probiotics effectively mitigated anxiety and depressive symptoms similar to conventional prescription medications. Whether it's a probiotic supplement or even better, the consumption of probiotic-rich foods, it's essential to support the digestive system to keep serotonin levels sufficient, therefore reducing the occurrence of mental health disorders.
If you’re looking for guidance optimizing your digestion, reach out to me to get on my waitlist! I plan to start accepting new clients in Spring of 2024.
REFERENCES
Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E., & Wakefield, S. (2017). Gut microbiota's effect on mental health: The gut-brain axis. Clinics and practice, 7(4), 987. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641835/
Djoussé, L., & Gaziano, J. M. (2009). Dietary cholesterol and coronary artery disease: a systematic review. Current atherosclerosis reports, 11(6), 418–422. https://doi.org/10.1007/s11883-009-0063-1
Nutritional Therapy Association. (2022). Immune System. Nutritional Therapy Association Student Guide, 61-62.
Nutritional Therapy Association. (2023). Endocrine Introduction. Nutritional Therapy Association Student Lecture, 01:31.
Nutritional Therapy Association. (2023). Cardiovascular Introduction. Nutritional Therapy Association Student Lecture, 01:39.
Nutritional Therapy Association. (2023). Detoxification Function. Nutritional Therapy Association Student Lecture, 03:14.
Perlmutter, D. (2015, August 25). Healthy Gut, Healthy Brain. Retrieved from: https://experiencelife.lifetime.life/article/healthy-gut-healthy-brain/
