I am going to cover the topic of digestion in a few separate parts so as not to overload and confuse the living daylights out of you. You should view digestion as a foundational aspect of your overall health. Chances are if you suffer from some sort of digestive ailment (and most of us do) then this will be reflected in other areas as well. Poor digestion can affect your endocrine, immune and cardiovascular health. In this first part I will cover some basic principles about digestion, and discuss the way digestion is supposed to work. In Part 2 of Digestion 101, I will cover the dysfunction of digestion.
In Nutritional Therapy we have some very succinct statements that we like to call Big Ideas. These are simple statements that allow us to convey the importance of the systems of our bodies. Here are 3 Big Ideas for digestion.
First, digestion is a north to south process. In other words, digestion begins in the brain and ends with waste elimination. Second, the big 3 organs from a nutritional standpoint are the stomach, pancreas and gallbladder. And last but not least, digestion is fundamental to Nutritional Therapy. Meaning without proper digestion you simply cannot be functioning at optimal health and wellness.
So, let us begin! Digestion begins in the brain. The sight and smell of food triggers your salivary glands to begin producing saliva. We’ve all said it right? “That smells/looks so good my mouth is watering!” You’re right. It is! This is the beginning of the digestive process. Now, before we get into the nuts and bolts I want to stress the importance of where and how we eat. Digestion can only happen in a parasympathetic state. We live in a world where we are chronically living in a sympathetic state. Simply put, we are hurried and stressed throughout our day. And its not just an occasional day. It is EVERY day. We eat standing up, rushing out the door and in the car. These are not places we should be eating. In order for digestion to function properly we need to be in a parasympathetic state. That means we need to be sitting down in a relaxed environment free from stress. I am sure this sounds impossible to some of you. I argue however that your health is worth taking this step. In addition, once that food touches your lips your goal should be to actually chew said food. Yep. Chew it. 30 times. You heard that right. If you want to live with a dysfunctional digestive system then keep swallowing big pieces of unchewed food. Your organs have to work so much harder to try and break down the food that your mouth and teeth were supposed to break down. So unfair. Do your job and chew your food. The manual and chemical breakdown of food begins in your mouth so do your part.
Once you have thoroughly chewed your food and salivary amylase has started to break down the carbohydrate it is then swallowed and enters the esophagus for passage into the stomach. At this point we will refer to that ball of food as bolus. The bolus enters the stomach through the cardiac sphincter and it is bathed in a wonderful bath of gastric juices. This is where adequate levels of stomach acid come into play. The acid bathes the stomach, disinfects the stomach, kills bacteria and parasites, and activates pepsin so the proteins in your food can be broken down. This allows the bolus to be broken down further into a paste called chyme. The chyme is very acidic in the stomach. Remember, this is a good thing!
The chyme then passes into the small intestine where the acidity of the chyme triggers the secretion of two hormones into the bloodstream. These two hormones, Secretin and Cholecystokinin (CCK) let your pancreas and gallbladder know that they have jobs to do.
Secretin stimulates your pancreas to release bicarbonate, which alkalinizes the very acidic chyme. In addition, the pancreas releases pancreatic juice and enzymes (proteases, amylases and lipases) to further break down proteins, carbohydrates and fats. CCK communicates to the gallbladder that it needs to release bile. The bile is necessary to emulsify and absorb fats. (Contrary to what you might hear about the gallbladder, it actually is an organ that you need.)
The small intestine is considered the highway to the bloodstream so I think you can surmise the importance of each of these organs working properly. Once the chyme has moved through the small intestine and nutrients have been absorbed the leftover chyme moves into the large intestine. The job of the large intestine is to recycle water, recycle waste material, as well as commandeer any lost nutrients that are still available. It does this with the help of the bowel flora. This is why it is so important to keep healthy bacteria thriving in our colons. It then converts these captured nutrients to vitamins K, B1, B2, B12 and butyric acid. Last but not least, the large intestine forms and expels feces.
In a perfect situation the above simple description of our digestive tract would happen just as I have stated. However, things do not flow this nicely for most of us. This is where the dysfunction comes in. Stay tuned as I will be sharing with you what a dysfunctional digestive system looks like in a future post.