Mini Lesson: Brain and Mouth

Video Transcript

Starting the Digestive Process

Today we are going to focus on where digestion begins, and this process starts before food even enters the body. Our brain reacts to seeing and smelling food by telling the body to start making the chemicals that are needed to digest food.  

Chemical Digestion

In our mouth, this means we start making saliva. This is a very important type of liquid with lots of specialized molecules, including enzymes. These enzymes are responsible for breaking apart certain parts of food, and the ones released in the mouth go after starches and some fat. This is why many refined carbohydrates like cookies, crackers, or bread seem to fall apart just sitting in your mouth, but protein foods pretty much stay in one piece.

When enzymes are responsible for breaking apart molecules, we refer to this as chemical digestion. This chemical breakdown of starches and fats is only one of the important digestive steps that happens in the mouth. The enzymes and chemicals released in the mouth and throughout the body can only break apart the molecules in food that they can touch.

Mechanical Digestion

We also need mechanical digestion, which is where large chunks of food are broken into smaller pieces. Chewing our food really well makes it so that the chemicals are able to reach more molecules in the food, and this has to happen before our body can get to the really important nutrients that are found in the food. 

This makes chewing a very important process because there is nowhere else in our digestive system that can break food apart this way. So, don’t skip this step! Even though most of the molecules in food are broken apart further along in the digestive tract, the chemicals and helpful bacteria in our digestive system count on this mechanical digestion so they can reach all the different molecules and do their job. Chewing is one of the few steps in the digestive process where we have a choice. Choose to do it well because it matters!

Chewing's Role in Digestion

This is a great place to show why we need to digest things properly to get the most out of the foods that we are eating. Even if we are careful to eat only the most nutritious foods, those nutrients don’t help our bodies if we can’t absorb them.

If we eat our food quickly without really paying attention to it to get those digestive juices flowing, or we only chew once or twice before swallowing, we are setting our digestive system up for failure. The chemicals released in the stomach and the small intestine will struggle to make up for the steps that were missed in the mouth. 

Food that is not chewed well or only partially digested not only creates problems in the digestive tract, but it creates a ripple effect throughout the body. 

How, you might ask? 

Supporting Nutrient Absorption...

The most obvious reason is that your body cannot take in all the nutrients that are stored in a food if it is not properly digested. Since every cell in the body relies on these nutrients to do their jobs, not getting enough nutrients can cause a lot of problems in the body. As new cells are formed without enough nutrients, we start to see issues, especially in the cells that only live for a few days, like those in the skin and the digestive tract. 

...And a Balanced Microbiome

And more specifically in the digestive tract, we also have tiny organisms like bacteria and fungi that also rely on the food that we eat.  Normally they are only meant to get the leftovers from the food that our body cannot digest, but undigested foods that are left in the intestines can feed different types of organisms, or they can get more food than they should and they start to grow out of control. When this happens, these organisms create all sorts of chemicals that cause problems in our digestive tract and can spread those issues to the body.