The Brain And Mouth – How Digestion Works

The brain and mouth are the starting points of the digestive process. Digestion is a north to south process. This means that food always travels down your digestive system (except when you throw up, but that’s either a sign of dysfunction or sickness). Because food travels down your digestive system, the parts at the top are the most important parts to support. If there is something wrong at the north end, it negatively affects everything below it.

The brain is where digestion starts. It is connected to the digestive system through millions of nerves. There is a huge connection between the brain and the gut that science has just scratched the surface of. In addition to normal functions like triggering the secretion of certain hormones that start/stop aspects of the digestive process, it has an intimate relationship with the gut. They are constantly sending signals back and forth with each other. The mouth is the start of ingestion. The mouth physically breaks down food. It also starts chemically breaking down food via enzymes in your saliva.

This post will,

• Explain the importance of the brain and mouth in digestion,
• Identify signs of dysfunction of the brain and mouth as it relates to digestion, and
• Inform you of simple changes you can make to help protect and support the health of your brain and mouth.

I know I’m a huge nerd when it comes to digestion, but hang with me! We’re going to try not to make this super textbook-y.

The Brain

Ah the brain! The brain controls pretty much everything. The digestive system is no exception. The cool thing about the brain and the digestive system in particular is that the digestive system can actually talk back to the brain! There’s an open dialog going between them at all times.

One of the ways you can feel this communication in your body is to think of your favorite food. Think about the texture, flavor, and smell. Is your mouth watering? That’s your brain triggering the digestive process to begin! Your hypothalamus is triggering your vagal nerve to start producing enzyme rich saliva to aid in digesting your favorite food.

Our gut is often called “the second brain” or “little brain” because it acts like a brain. The extrinsic nervous system or ENS (which is what regulates the digestive process) uses the same chemicals and cells as the brain does to help control our digestion. It also can communicate to the brain the same way the brain communicates to it.

Why Does The Brain Matter In Digestion?

When you are feeling super stressed, excited, anxious, or sad, your body is in a sympathetic state. When you are feeling calm, relaxed, content, or peaceful, your body is in a parasympathetic state. The process of digestion can only be done properly in a parasympathetic state. When you are in a sympathetic state, your body slows down digestion to a near stop. This is to conserve energy to focus on whatever issues is causing your heightened state of emotion.

The way you feel can drastically affect how well you digest food. My favorite book on this subject is The Mind-Gut Connection by Dr. Emerson Mayer. In his book, Dr. Mayer finds that his patients have trouble digesting foods as an adult that they ate while having a strong negative emotion when they were younger.

You have probably experienced this in your own way. Losing your appetite when someone gives you sad news or feeling nauseas when your anxious. Your body doesn’t typically want food when your not relaxed.

What about stress eating? Good question! Stress eating is often an issue my clients face. When you are stressed for a prolonged period of time, your body will switch from fight or flight to mode to more of a “wired” state. Cortisol is pumped from your adrenal glands during this time which can cause an increased appetite (stress takes energy). We live in a pretty stressful world already between work, family, friends, finance, health, etc. The pandemic has only made it worse. There are a lot of people who get stuck producing high levels of cortisol. These people often struggle with stress eating.

How To Keep Your Brain Healthy

Because the brain is the furthest north you can get in the digestive process, dysfunction in the brain can cause issues all the way down the digestive tract. The biggest issue I face in my practice is clients eating in a sympathetic state. This can cause Low stomach acid production (hypochloridria), slow gastric emptying (food staying in the stomach for too long).

You can support brain function by adding foods high in healthy fats into your diet. Foods high in B vitamins, iron, vitamin D, vitamin C, calcium, magnesium, zinc, etc. are also important. The bottom line is to eat a diet with a wide variety of nutrient dense foods. That way you’ll be sure that your getting the nutrients you need.

Some of these foods are:

• Oily fish (salmon, sardines, trout, eel, tuna)
• Nuts and seeds
• Colorful veggies (both raw and cooked)
• Colorful berries and fruits (raw)
• Healthy fats from organic, cold-pressed olive oil, avocado oil, coconut oil, grass-fed ghee, and grass-fed butter (NOT canola oil, vegetable oil, rapeseed oil, cottonseed oil, sunflower oil, or corn oil)
• Organ meats

Practical Diet And Lifestyle Changes

You can support brain health is several ways. Adding in some of the foods on the list above is a great place to start for in regards to dietary changes. Taking out foods that you know you have a sensitivity to is another good dietary change to make. Brain fog can be caused by an inflammatory response. I see this a lot in my clients who struggle with leaky gut. Just like with any organ, the longer an individual has inflammation in the brain, the higher risk they have of developing disorders/illnesses.

Lifestyle changes that make the biggest impact on the brain are sleep and stress. Poor sleep quality or not enough sleep is another cause of brain fog. It also causes many other systems to start to decline. Your immune system weakens, your memory is impaired, and you are more likely to overeat. Diet (blood sugar regulation in particular) plays a large role in your sleep patterns. Paying attention to how much sugar your eating (I guarantee it’s more than you think) and trying to keep it to a minimum will help you get more quality sleep. Implementing a nighttime and a morning routine (preformed at the same time every day) will also help prepare your body for sleep. Be sure to make your room as dark as possible, stay away from blue light (from electronic screens) or get blue light blocking glasses, and try to get some sun first thing in the morning (this triggers healthy hormone production).

Stress levels can be hard to manage sometimes. The main goal is to minimize them whenever you can. If you struggle with chronic stress or an anxiety disorder please talk to a therapist. Following the dietary recommendations above (removing food sensitivities and adding in foods that support brain health) will help with stress. However, we should also consider adding other activities that help manage stress into our lives on a daily basis. These could look like:

• Taking time to do a hobby we enjoy
• Creating a daily schedule to manage stress
• Tapping
• Physical movement
• Spending time in community with other people you enjoy
• Setting healthy boundaries
• Journaling
• Spending time outdoors, in nature
• Deep breathing
• Positive self-talk

The Mouth

A lot of digesting happens in the mouth. Food is both chemically and physically broken down in the mouth. Unfortunately, We often don’t give the mouth a chance to play as big of a role as we should.

The Mouth’s Role In Digestion

The mouth breaks food down physically when you chew. Your teeth and tongue pull apart large pieces of food into more manageable food particles. As you chew your saliva starts to chemically break down your food. There are enzymes in your saliva called amylase and lipase. These enzymes start the breakdown of carbohydrates and fats.

This whole process can only be done properly if the food stays in your mouth long enough. Chewing thoroughly is not something most of us prioritize. We often want to get onto the next thing after eating. The ability to eat quickly is something that is praised in American culture. So much so, that eating quickly becomes a habit we practice at every meal to some extent.

When food doesn’t get chewed properly in the mouth, the stomach has to work harder to breakdown the food so your intestines can absorb the nutrients from it. But, the stomach doesn’t have teeth and your stomach acid can have a hard time keeping up when you eat quickly (especially when you’re in a sympathetic state). When larger food particles enter your intestines, they can wreck havoc. Your intestines have a harder time absorbing them which leads to symptoms like bloating, undigested food in stool, gas, constipation, diarrhea, indigestion, bacterial infections in the gut, etc.

How To Keep Your Mouth Healthy

A healthy mouth is critical for healthy digestion. As we saw above, if something goes wrong at the very beginning, it negatively affects the rest of the digestive process. Your teeth, gums, and tongue are what make up your mouth. The health of these three things are what you need to focus on for oral health. They are most affected by changes in the bacteria in your mouth and saliva production. I will go over some ways you can take care of your mouth, but I’m not a dentist. You should absolutely consult your dentist about how to best care for your oral health.

Your mouth has microbes in it at all times. The goal is to keep a balanced microbiome in your mouth (just like your gut!). A balanced mouth microbiome will help protect your teeth and the mucosa membrane of the mouth. Most toothpastes, mouth washes, and teeth whitening products use harsh chemicals to get rid of bacteria. This can disrupt the microbiome inside your mouth.

I would recommend choosing more natural alternatives to mouth washes like oil pulling, tongue scraping, swishing salt water, and staying hydrated. Teeth whitening can also be done naturally by brushing your your teeth after every meal. While I recognize that bright white teeth are in vogue that is not the natural color of adult teeth. Often, bright white teeth are actually less healthy and strong than teeth that have more of a cream color because of the harsh chemical process that the bright white teeth had to go through.

Any dentist will tell you that what you eat has an effect on your oral health. High sugar foods and highly acidic foods are damaging to your teeth when eaten in excess. Snacking throughout the day is also not good for tooth and gum health. Frequent snacks do not give your mouth enough time to clean out food particles and naturally re-mineralize.

Practical Diet And Lifestyle Changes

You can improve your oral health by:

• Eating a wide variety of nutrient dense foods and limiting sugary and highly acidic foods
• Brushing your teeth at least twice a day
• Oil pulling
• Tongue scraping
• Keeping harsh chemicals (like sodium lauryl sulfate) out of your oral care products
• flossing or using a water pick
• Hydrating throughout the day

Nutrient dense foods will help your body get all the nutrients it needs to have strong, healthy teeth and gums. Brushing your teeth and flossing properly and regularly will keep help food particles out of your mouth. Be gentle when you brush and use gentle ingredients in your products to minimize damage to your teeth.

Tongue scraping is great for eliminating bad breath and getting rid of bad bacteria that causes tooth decay and gum infections. It can also enhance your ability to taste food!

Oil pulling is when you swish 1 tablespoon of oil (I use coconut oil) in your mouth for 15-20 minutes. This practice pulls bad bacteria from hard to reach places in your mouth. Do not gargle or swallow the oil and spit it out in the trash (not the sink because it could clog your pipes) when your done.

You should also strive to chew every bite of food 30-40 times or until it’s a smoothie-like consistency. This will make sure your food is thoroughly broken down and can prevent issues south of the mouth in the digestive system from developing or worsening. If you are drinking a smoothie or something similar, it’s still smart to give it a few chews. This will give the enzymes in your saliva time to interact with your food and chemically break it down.

Summary

The brain is highly involved in the digestive process. It talks to your gut and your gut talks back! Digestion is a parasympathetic process, meaning it only works properly when your relaxed. Stress will hinder the digestive process. Keeping your brain healthy involves being intentional about eating food, choosing a wide variety of nutrient dense foods to keep your brain nourished, and prioritizing sleep and stress relief.

Your mouth is the place where the actual breaking down of food begins. Most people do not eat slowly enough for the mouth to do its job properly. Your mouth needs to physically and chemically breakdown your food. This can only happen if you’re chewing your food thoroughly. 30-40 chews is the guideline here. If you are drinking your food (like a smoothie) it’s still important to give it a few chews to give the enzymes in your saliva enough time to do their job. Proper oral hygiene is also important to keep the mouth healthy.

Do you have questions or comments? Pop them down in the comment section! Let’s start a dialog!

My clients are often surprised at just how little they think about food while they’re eating or at how few times they chew food. Paying attention to your food, eating in a relaxed state of mind, and chewing thoroughly are recommendations I would give to pretty much everyone. They’re habits worth developing.

Have a wonderful week!