Digestion 101
The belief that good digestion is vital to looking and feeling our best is not a new idea. After all, Hippocrates said "All disease begins in the gut" over 2,000 years ago. This simply means, that when digestion is working properly, other areas of the body will often be in balance. Obviously, blood sugar, hydration and all areas are important, but fixing digestion is usually the first step in addressing issues like vitamin deficiencies, skin issues and many other areas.
Digestion could easily be a whole series all by itself because its a long, complicated process. For this post I'll talk about the basics of how digestion should work and also
some
of what happens when digestion goes wrong. I know it doesn't sound very exciting, right? But I promise, if you have heartburn, constipation or diarrhea, bloating or belching after meals or other obvious digestive issues, you'll want to know how this works!
How Healthy Digestion Works
The first thing to understand is that digestion is a north to south process, meaning it starts in our brain and works through our body, all the way down to the Large Intestine, north to south. And each area of the body depends on the areas above it to be functioning properly, so they can do their job. For example, food passes through the stomach before it reaches the small intestine. So the small intestine depends on the stomach to break down food to a certain point, before it even reaches the intestine. We have to get the upper body right, or the areas further down won't work.
Digestion actually begins in the brain! When we see and smell food, in anticipation of a meal, our brain triggers the production of certain enzymes and hormones including salivary amylase. When we chew food, amylase in saliva, is mixed with the food, and starts to break down carbohydrates. Without the enzymes in saliva, the rest of the body can't possibly break down all of the carbs. So the saying "my mouth is watering" is a really good thing!
Once the food, now called bolus, is mixed with saliva and swallowed, it passes through the esophagus and at the bottom of the esophagus there's a valve, the cardiac sphincter, that opens and lets food pass from the esophagus, into the stomach. The cardiac sphincter is meant to only open one way. It lets food pass from the esophagus into the stomach, then it closes. When we chew our food enough to break it down and we're in a relaxed, or parasympathetic state, our stomach triggers the secretion of gastric juices. These gastric juices include Pepsin to break down proteins and Hydrochloric Acid (Hcl). In fact, the stomach is all about acid! The stomach churns the food and mixes it with all the gastric juices. The acid's purpose is to bathe the stomach, kill bacteria and parasites and to break down food even further. Once the food, now called chyme, is acidic enough, the pyloric sphincter at the bottom of the stomach, opens to let the chyme pass from the stomach, into the small intestine.
As the chyme enters the small intestine, the acidic state of chyme triggers the small intestine to release mucous to protect it's own walls from the acid. The small intestine also releases two hormones, Cholecystokinin(CCK) and Secretin.
CCK is triggered by the presence of fat in the chyme. CCK's job is to trigger the gallbladder to release bile. Bile breaks down fats in our food.
Secretin's job is to trigger the pancreas to release sodium bicarbonate. The chyme leaves the stomach highly acidic. While the acid is great for the stomach, it's too acidic for the small intestine, so the sodium bicarbonate is produced to neutralize the chyme and make it more alkaline.
90% of digestion takes place here in the small intestine. The release of secretin, CCK, bile and sodium bicarbonate is essential for healthy digestion, but keep in mind, that if the HCl wasn't produced in the stomach, then secretin, bile, CCK and bicarbonate won't be secreted.
From the small intestine, the chyme passes into the Large Intestine where the last bits of water and nutrients are absorbed, and then excreted.
Those are the basics of how healthy digestion works.
What Can Go Wrong In Digestion
Digestive dysfunction can happen anywhere in the process, so I'll just go north to south and talk briefly about some of the things that can go wrong.
Heartburn/GERD
Remember, the stomach and small intestine depend on us to be in a relaxed, or parasympathetic state, for digestion to do its job. Eating while standing, driving or while in a hurry means our body is not relaxed. When we rush through our meals and eat in this stressed, or sympathetic state, gastric juices including Hcl, in the stomach are not produced. A lack of stomach acid can be caused by stress but also things like overconsumption of carbs or alcohol. Without enough stomach acid all sorts of things can go wrong.
We also must chew each bite food thoroughly to break it down to a certain point. If we don't chew enough, amylase is not secreted and carbs are not broken down. When we swallow pieces of food that are too large, the areas further south can't possibly do the rest of the breaking down. These large pieces of food can stay in the stomach way longer than they're meant to and they begin to rot and putrefy. The rotting food sits in the stomach and starts to produce gases that build pressure. As the pressure builds up, it forces the valve between the stomach and esophagus to open. Remember, this valve is only meant to open one way, for food to pass from the esophagus down into the stomach. But the buildup of pressure forces the valve back open, so pressure is released and now the chyme can backflow into the esophagus. This is not a good thing! Things should only move down in digestion, not up. Even though this all happens from a lack of stomach acid, there is always at least some acid present in the stomach. The chyme that is now forced to go up, although not acidic enough for the stomach, is way too acidic for the esophagus. This causes burning of the esophagus. And this friends, is what we call heartburn!
So if you get heartburn, it might seem like, or maybe you've even been told by doctors, that its caused by
too much acid
in the stomach. When in fact,
heartburn is caused by too little acid
!
Millions of people are taking over the counter antacids or are prescribed PPIs for their heartburn issues. This is a big deal. The acid suppressors do just what they say they will, suppress acid. But like I explained above, heartburn actually happened as a result of too little Hcl, so taking a medication to get rid of acid actually backfires.
The acid blockers work by neutralizing the chyme that has entered the esophagus, so the burn goes away. This is why they seem to be helping people. We rush through meals, stressed, not chewing enough, so stomach acid is not produced like it should be, the food begins to rot in the stomach, pressure builds, the chyme is forced up into the esophagus which burns, we take an acid blocker to neutralize the chyme, the burn goes away. Well, that must mean the medication was necessary, right? Not exactly. For one thing, the medication is only a band-aid fix. It's temporary, so most people end up relying on these pills every time they eat. In this case, your stomach will never be able to make enough acid because you're constantly working to block it with the antacids. So most of the time, people become dependent on these medications and end up on them for years. Heartburn meds were never meant to be long term. They were intended to be a temporary solution. In fact, if you read the box on most of these, you'll see a warning that they shouldn't be taken for longer than 2-8 weeks!
In Nutritional Therapy, we work with clients by getting to the root cause of whatever the issue is. So in the case of heartburn, we'll help the client learn how to heal the gut and start producing acid again. This is why I love what I do! Getting to the root cause, instead of just covering up symptoms, is the key to healing.
Helicobacter Pylori
Another issue that can happen from a lack of stomach acid, is H Pylori. This is an infection caused by a bacteria allowed to thrive in the digestive tract. One purpose of stomach acid is to kill pathogens in the gut like yeast, bacteria, viruses or parasites. If there isn't enough hydrochloric acid, these pathogens are allowed to thrive. H Pylori is very common, about 2/3 of the population has it, and when it gets out of control it can lead to ulcers or in extreme cases, stomach cancer.
Duodenal Ulcers
Ulcers are just another thing caused by digestion gone wrong. The very top of the small intestine is called the duodenum. In healthy digestion, once the chyme is acidic enough, its allowed to pass from the stomach into the small intestine, where secretin triggers sodium bicarbonate to neutralize the chyme. But when the chyme isn't quite acidic enough, bicarbonate is not triggered and chyme goes into the small intestine without being neutralized and burns the lining of the duodenum, forming these painful ulcers.
Leaky Gut
Intestinal permeability, commonly known as Leaky Gut, happens when undigested proteins enter the small intestine. Again, its the lack of hydrochloric acid and pepsin in the stomach, that let undigested proteins make their way into the small intestine. The lining of the small intestine is made up of microvilli, fingerlike protrusions that fit tightly together. The villi are meant to be "selectively permeable". So they let certain nutrients pass through, but keep other substances out. When undigested food makes its way into the small intestine, the lining of the intestine gets irritated and the villi separate or become "leaky". The openings in the lining allow substances to enter from the gut into other areas of the body. Food that should have been nourishing, is now seen as an assault on the body, leading all sorts of immune issues. The symptoms of leaky gut are countless and can be anything from allergies to skin issues, like psoriasis or eczema, to autoimmune disease.
Leaky gut can be caused by many other things, like stress or medications, but here we're just talking about digestive causes. I will definitely do a post all about Leaky Gut soon because its super common and most people have it, have no idea its at the root of whatever issue they're dealing with!
Gallbladder Issues
Gallbladder issues are commonly caused by low fat or 'bad fat' diets. In healthy digestion, the acidic chyme enters the small intestine, and at this point fats present in the diet, trigger the gallbladder to release bile. Bile is what breaks down fat. It might seem like a low fat/no fat diet would mean bile isn't even necessary, right? But this isn't true at all. Bile is always present in the gallbladder. But what happens if bile is never triggered to be released? It simply stays in the gallbladder and becomes old and thick. Without the release of bile, fats are not absorbed and this buildup of bile is what often leads to gallbladder pain and more serious issues, which in many cases results in the removal of the gallbladder.
Dysbiosis
The gut is meant to have a balance of good and bad bacteria. By the time chyme enters the large intestine, most digestion has already taken place. It should be completely broken down so the large intestine can grab any leftover nutrients. But in digestive dysfunction, maldigested proteins and carbs enter the large intestine and degenerate here which causes an imbalance in the gut flora, or bacteria. This means that there is more bad bacteria in the gut than good bacteria. This imbalance is called dysbiosis. Dysbiosis weakens the colon, leading to inflammation, and can cause diverticula, IBS, Crohn's disease, colitis and celiac disease. Probiotic supplements and fermented foods like kimchi, sauerkraut and kombucha can help restore a healthy balance. If there is an imbalance in the gut flora, a probiotic food or supplement is essential but we still need to work on the areas of digestion that take place further north in the body, so that maldigested food never enters the large intestine in the first place.
Dysbiosis can be caused by other issues too, most commonly from the use of antibiotics. After a round of antibiotics, its a good idea to follow up with a high-quality probiotic. I always recommend this one from
.
Small Changes Make A Big Difference
When I first learned about the importance of proper digestion, I thought there's no way these small changes can really make a difference. Can sitting down for meals actually help? Is chewing that many times really necessary? But these small steps together are exactly what make up healthy digestion. I promise the small change make a big difference.
One of the first we learned in Nutritional Therapy, is that when we get Digestion right, other areas often balance themselves and many symptoms start to subside. So maybe a client shows signs of vitamin deficiencies. The instinct is to increase vitamin consumption with food or supplements. That person might actually be eating the best diet possible, but if they have any digestive issues, then they won't be absorbing the nutrients in the food. Fix digestion, then food is completely broken down and nutrients can be absorbed. It may sound complicated but just remember, when we get it right, it can make a huge difference in how we feel!
We're all super busy people and often spend our days rushing from one thing to another just trying to get everything done for the day. Meals are no exception. We seek out the fastest, most convenient food because, if we stop to cook our meals, how else can we possibly get everything else done? But spending a little time preparing your food, then sitting down to enjoy your meal, can make a huge difference in how well you digest the nutrients and how well your body can use those nutrients.
Rest to Digest
After grabbing the fastest, most convenient meal we can get our hands on, its common these days to eat while standing, driving or on the go. When we're rushing from task to task all day, our body is in a stressed state. It might be a feeling we've grown accustomed to, as in it feels normal to be rushed, but that doesn't mean it isn't a stressful state for your body. When we're stressed, the digestive process is second priority. Actually, stress is always prioritized over other functions in the body, including hormone production, blood sugar control and digestion. Digestive enzymes and hormones are secreted when we're relaxed and chew our food. Practice sitting down and taking a few deep breaths to relax before each meal.
Chew each bite 25-30 times
It might sound obvious but how many times do you take a bite, chew chew chew, then swallow and on to the next bite? Rushing through meals like we rush through the rest of our day. I truly believe that the stressed, rushed state we're all running around in everyday, is part of the reason people are feeling so poorly. Good health starts with proper digestion. The goal of digestion is to break down food so small that nutrients can be absorbed and used by the body. Chewing is the very first thing that has to happen for food to be mixed with the salivary amylase to begin breakdown. So the key here is take a bite, put your fork down between bites and chew thoroughly.
Limit the amount of water you drink with each meal
Hydration is essential and most people are not drinking nearly enough water. Aim for half your body weight in ounces per day. Example: if you weigh 150 lbs, divide that in half to get 75 ounces water each day. Add in more water if you drink diuretics like coffee, tea, juice or alcohol which are dehydrating to the body. But sip that water throughout the day. If we chug a big glass of water with our meals, we dilute the gastric juices in our stomach. Remember, the stomach is all about acid. Too much water can bring the acidic state down, so instead just sip water all day and just have no more than 8oz with meals.
If there are still digestive issues once the lifestyle changes have been made, then a Nutritional Therapy Consultant or other functional practitioner can help!
Digestion can't be covered in a single post so I definitely plan on talking more about the things that can go wrong, like heartburn and Leaky Gut, in future posts. If you have questions about any of this or would like to hear more about any specific area I touched on, please leave a comment below. Your feedback helps me to know what it is you're interested in! Thanks again for being here and taking the time to visit Prepared Simply!