Digestion – What You Need to Know
About 600 million years ago, tube worms evolved and subsequently developed into every animal you can think of from dinosaurs to humans. The “tube” in tube worm is the digestive tract. That should tell us something about how important digestion is to us all. We all have a mouth at one end and an anus at the other with a continuous tube in between to digest our food. Without a digestive tract, we wouldn’t be alive. This article aims to help you understand how yours works and what to do if it isn’t working as well as you’d like. Please read on.
The essential thing to know about your digestive process is that it proceeds from top to bottom in an orderly sequence. You may have been diagnosed or know someone diagnosed with acid reflux or colitis, but to really understand what is happening, you have to take a global view of the entire digestive tract. If you or your doctor treat your stomach as if it was on a separate planet from your pancreas or intestines you will have a host of downstream problems. My first advice is to take a holistic approach.
That digestive sequence actually starts in our mind. We think about food. We see food. We smell food and we start making digestive juices. This is the way it is supposed to work. Far too many of us put food in our mouths while multi-tasking or otherwise distracted. Eating in this way is the start of most digestive problems, including obesity (If you don’t feel satisfied and nourished by your food, you will likely keep eating until your are overly full).
Imagine you are in Europe at a sidewalk cafe. You are with friends, the day is pleasant and you have plenty of time set aside for a relaxed meal. You enjoy an appetizer and then your plate arrives. Your food is beautifully prepared and smells delicious. The aroma wakens your hunger. You bring a bite to your mouth, close your eyes, put down your fork and savor the taste as you slowly chew. Ahh….
In contrast, most meals in America are eaten in the car.
Europeans think our obsession with fast food is ridiculous. Why would you want fast food? Do you want all your pleasures to be over with quickly? What’s the hurry? Eating is a physical and emotional pleasure that we get to enjoy several times per day. Why do we turn it into a quick re-fueling? Life is to be enjoyed.
Okay, okay, you have so much work to do. You don’t have time to enjoy your meals in a relaxed way. Here’s what you can do. At home when you are able, practice this; Make a colorful, flavorful meal with an enticing aroma. Sit down with your plate, close your eyes and relax your breathing. Feel your body relax. Feel your shoulders relax. Feel your abdomen expand as you inhale. Breath ten times. This is a traditional time to give thanks for all that is good in your life. You are shifting from your “fight or flight” nervous system to your “rest and digest” nervous system.
When you open your eyes, look at your food and appreciate the beauty and aliveness on your plate (if you are looking at a plate of mystery meat in greasy grey sauce with a slice of unripe tomato on limp iceberg lettuce, go back to the kitchen and start over. Food should look and smell enticing). Pick up your fork, bring a bite to your mouth, close your eyes and savor the flavor as you chew. After you have liquified and swallowed that bite, open your eyes and have another. A few bites in, you should be able to read or have a conversation without losing that sense of inner peace. I expect you will find that this is a delightful and relaxing experience, one you will want to repeat. I understand that you won’t be able to do this at work, but if you do this at home you may find that just a deep breath and a brief closing of your eyes on the first bite may be enough to trigger this relaxed state of eating while you are at work.
By the way, closing your eyes and putting down your fork is a way to break the habit of constantly searching for the next bite instead of enjoying the one in your mouth. This attitude of being present with your moment to moment experience can be transferred to your every conversation and interaction with the world. Eating can be your daily meditation practice. Fully receiving nourishment from your food can translate into fully receiving the gift of other people and experiences in your life. When someone gives you praise, do you breathe in that praise and own that you are worthy of those words or do you brush it off with, “Oh, that was nothing” or some similar avoidance. If you can’t receive food with grace, how can you say, “Yes I am good/kind/honest” or whatever the praise is about? Practice receiving the nourishment of food and deal with whatever self esteem issues arise. Then take what you have learned and apply it to your relationships.
Next stop – Your Stomach!
Anticipating, smelling and savoring your food increases saliva in your mouth and gastric juices in your stomach. Relaxing while you eat also brings blood to your digestive tract. Chewing your food breaks down cell walls in the food, making the nutrients inside available to be digested. An enzyme in your mouth called salivary amylase begins the process of breaking down starches.
When you swallow, the food travels down your esophagus, through a ring of muscle called the cardiac sphincter (called cardiac because it is close to the heart) and into the stomach. The esophagus is in the cavity containing your heart and lungs, the cardiac sphincter and stomach (and all subsequent digestive organs) are located below your diaphragm in your abdominal cavity. While the job of your teeth and saliva is to grind food into a digestible puree and begin breaking down starches, the job of your stomach is to continue churning and mixing the food with pepsin and hydrochloric acid to begin protein digestion.
The stomach of course, is just a specialized part of your digestive tube. It makes itself into a separate chamber by closing the cardiac sphincter at the upper end and the pyloric sphincter at the lower end. Both those rings of muscle close to trap the food with caustic, protein-digesting fluids in the stomach. The stomach lining isn’t injured by the acid and pepsin. Hydrochloric acid would burn other tissues (as it does in the case of acid reflux into the esophagus and duodenal ulcer in the upper small intestine). So as the stomach fills and the acid is released, the rings of muscle (sphincters) at the cardiac and duodenal ends close off the stomach so it can do its work.
In addition to beginning protein digestion, hydrochloric acid also kills bacteria that may have entered with your food. What if you don’t have enough stomach acid? An article in the Journal of the American Medical Association estimates that 33,000 Americans die every year from hospital acquired pneumonia because they are taking anti-acid medications.i ii Get that? Die from pneumonia. If they had normal stomach acid, the bacteria would have been killed rather than allowed to cause infections (including but not limited to pneumonia).
Many nutrients but most particularly Calcium require hydrochloric acid so that they may be absorbed. That’s why people who take proton pump inhibitors (a very strong class of anti acid) suffer higher rates of osteoporotic fractures. iii
If anti-acid medications are so dangerous, why are they prescribed? Well, they stop the pain of acid reflux (heartburn) and some doctors still think they prevent ulcers. Let’s start with the acid reflux.
It used to be that doctors and laypeople alike thought that the stomach produced too much acid in response to stress. I remember ads on television when I was a kid showing fire in the stomach of a stressed person being extinguished by anti-acids). Doctors however, should have known better. Stress causes a reduction in stomach acid. Remember, stress triggers a fight of flight response. You don’t make acid to digest food when you are fighting or running. Low acid in the stomach from “eating on the run” fails to fully close the cardiac sphincter. Muscular restriction and lack of blood flow in the stomach pushes the food back up the esophagus. The body wasn’t prepared to receive food. The stomach wasn’t relaxed and receptive. The stomach juices weren’t released. The sphincters weren’t closed. The top down, sequence of digestion wasn’t properly started in a person who didn’t take the time to slow down and relax while eating. So yes, eating on the run causes heartburn, but it is not because there is too much stomach acid. Quite the contrary.
So how to address acid reflux? First, eat consciously. Relax and enjoy your food. Second, avoid overeating. When the stomach is over full, the cardiac sphincter can’t contain the excess food. Third, avoid eating anything within four hours of going to bed. When you lie down, food pushes up against your cardiac sphincter in a way that it doesn’t when you are upright. You want your stomach to be empty when you lie down at night. Dinner should not be your heaviest meal of the day and it should not occur late in the day. I understand that for most people, dinner is when you finally relax and can eat a meal in peace. I don’t know how you can re-arrange your schedule to have a relaxed lunch and a light dinner. I just know that you will avoid a lot of digestive problems if you do.
As an example, one of my patients – a successful business man – had been on proton pump inhibitors (Nexium in this case) for about 10 years. It was no longer working. He had terrible stomach pain and acid reflux. My advice was to have only a low fat vegetable soup for dinner and to eat nothing after 6:00 PM. I told him he would continue to have pain for about a week and then it should start to improve. That is exactly what happened. The lining of his esophagus repaired and the pain subsided. He no longer had acid reflux and no longer needed the medication. In a couple of months, he also lost a lot of extra weight.
So what about ulcers? Don’t people need to take anti-acids to prevent ulcers? No. Ulcers are caused by low stomach acid.iv Yes, low stomach acid. This was first discovered in 1982. The mechanism of ulcers is that low stomach acid allows the overgrowth of a bacteria called Helicobacter Pylori (H-Pylori for short).v H-Pylori infection causes ulcers. The most effective treatment of stomach ulcers is antibiotics paired with bismuth (remember Pepto Bismol?). When Australian researchers Barry Marshall and Robin Warren first discovered and promoted the idea that ulcers were the result of H Pylori overgrowth, they were slandered and attacked in the press all around the world by gastroenterologists who saw their livelihoods at risk. Cutting out ulcers was good business. Prescribing antibiotics is not. At this point though, the confirming research is unassailable. In 2005, Marshall and Waren received the Nobel Prize in medicine for their discovery. Again, eating in a relaxed way promotes normal stomach acid. Normal stomach acid suppresses H Pylori and prevents ulcers.
While we’re on the topic of H pylori, it’s worth noting that H. pylori infection is also the cause of gastric and gastroesophageal cancer. Another good reason to take time and enjoy your food.
Where does the food go next?
When the food is sufficiently mixed, churned and exposed to pepsin and hydrochloric acid, the valve at the lower end of the stomach (pyloric sphincter) opens to let a little food at a time move on to the first part of the small intestine known as the duodenum. The beginning part of the duodenum is also where the pancreas and gallbladder contribute their juices to the mix. The valve that releases bile and pancreatic enzymes into the duodenum is triggered to open by contact with acidity in the food leaving the stomach. Again, reduced acid means reduced release of bile and pancreatic enzymes. Each step in digestion is triggered by the preceding step.
Pancreatic enzymes actually do most of the work of digestion. These enzymes digest protein, carbohydrates and fats. The pancreas also releases bicarbonate to neutralize stomach acid. This prevents damage to the small intestine. If there isn’t enough acid to trigger the release of bicarbonate (or if there is a blocage in the pancreatic duct) the excess acid could cause a duodenal ulcer.
From here on down the small intestine, the enzymes break down the food and the nutrients are absorbed into the bloodstream. From there, the nutrients go to your liver and on to the rest of your body.
Speaking of the liver, that is where you produce bile. You can think of bile as a soap. Bile emulsifies fats. In other words, it allows fat to break up into small particles and mix more easily with water. This in turn creates more surface area for the fats to be broken down by pancreatic enzymes. Between meals, bile accumulates in your gallbladder. When food hits your small intestine, the gallbladder contracts and pushes bile out the same tube (common bile duct) as your pancreas and through the same valve (pancreatic sphincter) into your duodenum.
One of the components of bile is cholesterol. Your liver gets rid of excess cholesterol by making it into bile and excreting it into your intestines where it binds with fiber and is carried out to the toilet. If you do not have good digestion and adequate fiber, the cholesterol reabsorbs back into your bloodstream, where it can increase your risk of cardiovascular disease.
In addition to breaking down and absorbing nutrients in your food, the small intestine also produces serotonin, the hormone that makes you feel relaxed and happy after a good meal. This is the same hormone that is potentiated by drugs known as SSRI’s or selective serotonin re-uptake inhibitors. Examples include prozac, celexa and lexapro. As a society, we are heavy consumers of SSRI’s, anti-acids, osteoporosis drugs and fast food. Are you seeing a pattern here?
After most of the nutrition is absorbed in the small intestine, the food moves on through the ileocecal valve to your large intestine. The job of the large intestine is primarily to absorb water and minerals. Most of the good stuff has already been absorbed. I should note that if digestion wasn’t good upstream, there will be too much nutrient available for bacteria in your intestines, leading to inflammation and infection in the colon (colitis/irritable bowel). The bacteria that you want in your large intestine thrives primarily on soluble fiber, the stuff you get from eating your whole grains, beans, fruits and vegetables. Flax meal is also a terrific source of fiber and is effective in lowering your serum cholesterol. Healthy “probiotic” bacteria in your intestines can protect against a host of diseases and help us to digest our food. Taking antibiotics kills those healthy bacteria. Eating too much refined carbohydrate feeds yeasts and unhealthy bacteria. If you have yeast infections, sore throats, etc., you may want to cut down on your consumption of refined carbohydrates.
A side note on that topic is sinus infections. The sinuses are part of the same tube as the digestive tract. Chronic sinusitis is a sign of chronic inflammation in your large intestine. For many of my patients, not eating within four hours of going to bed cures their chronic sinus problems.
So how do you know if your digestion is working well? Here are a few clues:
Pain – There shouldn’t be any. If there is, note the location and what triggers the pain. Tell us or your primary care physician.
Gas – The digestive process produces gas – a lot of it – though most is reabsorbed in your intestine. If you are belching or burping, you are either swallowing air or you don’t have sufficient stomach acid. Slow down, chew well and enjoy your food.
If you are passing intestinal gas, note the smell. If it smells like a rotten egg, that indicates a problem digesting protein. Either you are eating too much or too fast (see above).
If you have copious amounts of odorless intestinal gas, you have consumed too much carbohydrate, particularly a combination of starch and a simpler sugar. Think bread and jam, pastries, cookies, etc. Odorless gas is a result of yeast fermentation. The gas bubbles in beer come from yeast fermentation.
Transit time – Food should pass from your mouth to the toilet in 24 to 36 hours. The average American transit time is 72 hours, meaning the average person is constipated. You can test your transit time by having a meal that includes a lot of beets. Beets will retain much of their color as they pass through your system. The problems associated with constipation are numerous, ranging from acne and hemorrhoids to colon and liver cancer.
Look at your bowel movements – An ideal bowel movement is 12 to 18 inches long, 1 to 1.5 inches thick and comes out easily in one piece. Not too hard or too soft. This should happen at least once per day. It can happen after every meal. Frequent soft bowel movements are diarrhea and can result in malabsorption. If you have diarrhea, try having foods that are warm and soft like soup rather than cold and chewy like salad. Ginger and cinnamon can calm and bring blood to the stomach. If diarrhea persists, talk to your health provider.
Infrequent, hard bowel movements are associated with constipation. If you have constipation, try drinking more water and eating more high fiber foods. Most importantly, try establishing good bowel habits. What that means is setting aside time to defecate. Ideally, sit down on the toilet after breakfast and allow yourself 5-10 minutes to relax and empty your colon. Nothing may happen for several days but if you persist, your body will get that you are serious. I understand you have to get to work or get the kids ready for school, but if you can establish this habit, you will feel better every day. If after breakfast doesn’t work for your schedule, try after dinner. Eating and defecating at regular times helps your whole system.
Normal stool ranges in color from light to dark brown. On any given day the color may be affected by what you ate the day before so some variation in color is not a cause for alarm, particularly if you have no pain or other symptoms.
If your stool is black and sticky like tar, you may have a bleeding ulcer (Digested blood looks black. hemorrhoidal blood is red). A black non-sticky stool may just indicate that you have consumed iron tablets or bismuth (Pepto Bismol). A bleeding ulcer generally includes nausea and stomach pain plus weakness and light-headedness.
If your toilet water has an oily sheen to it, or your stool is grey or clay colored you may have a gallbladder problem. Obstruction of the bile duct is often accompanied by yellowing of the whites of the eyes. Gallstones cause intermittent, cramping pain in the right upper abdomen.
Persistently yellowish stool in an adult may indicate obstructive disease of the pancreas such as pancreatitis or pancreatic cancer but may also indicate a malabsorption syndrome such as celiac disease.
I am not trying to make you obsessive about all this, just trying to give you some tools so you can monitor and report to your doctor any changes you might notice.
Many patients are embarrassed or dismissive about their digestive complaints and fail to mention them but digestion is an important part of your overall health. Remember, we are all just specialized tube worms. Poor digestion means poor quality of life. If you have a problem or question about your digestion, please bring it up next time you are in the office. We want you to feel well. Chiropractic offers manipulative techniques to restore normal position and function to digestive organs. Acupuncture has a wealth of treatment protocols designed to help all kinds of digestive issues. Let us know what we can do to help.
David Wells, D.C., L.Ac., MS (Nutrition)
i JAMA. 2009 May 27;301(20):2120-8. Acid-suppressive medication use and the risk for hospital-acquired pneumonia. Herzig SJ, Howell MD, Ngo LH, Marcantonio ER.
ii Chun-Sick Eom, Christie Y. Jeon, Ju-Won Lim, Eun-Geol Cho, Sang Min Park and Kang-Sook Lee. Use of acid-suppressive drugs and risk of pneumonia: systematic review and meta-analysis. CMAJ, December 20, 2010 DOI: 10.1503/cmaj.092129
iii Laura E. Targownik, MD MSHS, Lisa M. Lix, PhD, Colleen J. Metge, PhD, Heather J. Prior, MSc, Stella Leung, Msc. and William D. Leslie MD
Use of proton pump inhibitors and risk of osteoporosis-related fractures CMAJ August 12, 2008 179:319-326; doi:10.1503/cmaj.071330
iv Kusters JG, van Vliet AH, Kuipers EJ (July 2006). “Pathogenesis of Helicobacter pylori Infection”. Clin Microbiol Rev 19 (3): 449–90.
v Therapeurtic Advances in Gastroenterology. Helge Waldum, per Kleveland and Oystein Sordal. Helicobacter pylori and gastric acid: an intimate and reciprocal relationship. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5076771/