All About Digestion
Christopher L Bray MD PhD
Our digestive system is a wonderfully engineered system that extracts minerals and nutrients from a complex array of food sources. It really is a miraculous system. Think how hard we have to work to extract iron or copper out of rock quarries. Our humble little digestive system is extracting nutrients out of our food all day long. It filters out the things that may harm us and breaks down the things we need to stay healthy. It transports them into our blood stream to be checked over by our liver for safety before shipping little care-packages to all the tissues of our body. FedEx has nothing on our digestive system. It is like a finely coordinated humanitarian aid distribution network.
However, there are many ways that we accidentally disturb the digestive process creating problems for ourselves.
1. Chewing. Did you know that some experts tell us that our food should be chewed 20 or 50 times before we swallow? How many times are we in a rush and just jam food into our mouth and swallow as quickly as possible due to time limitations. Think about how hard it is for the little molecular-sized enzymes to work on those large chunks of food. It takes forever for our enzymes to break down those large pieces - so we end up with very slow stomach emptying, reflux, and some partially digested food entering our small bowel to feed the unhealthy bacteria - making them stronger and greedier.
2. Stomach Acid. Each day, I have to have a discussion with a patient about the use of PPI medications (Nexium, Aciphex, Prilosec, Prevacid, Protonix, etc). Chris Kresser has a great book about reflux. Many, many people are taking PPI medications to "control acid reflux." We literally spend billions of dollars a year on these medications (in 2012, Nexium revenues alone were $6 billion). However, it is important to understand that the body was made with acid in the stomach for a very good reason. More than 90% of people have burning and reflux symptoms due to their lower esophageal sphincter inappropriately opening AND NOT because of too much acid production. Indeed, most people that have LOW stomach acid have poor digestion and therefore slow digestion and they get reflux symptoms. The cells that make acid in the stomach are most prevalent in the 20s and then decline with age. There are also inflammatory and autoimmune processes that destroy these cells that make acid. Fixing acid reflux is often dependent on weight loss, changing what you eat, how much you eat, and when you eat. That is the subject of another article. Regardless, you need sufficient acid in your stomach to 1) activate your digestive enzymes and 2) help kill pathogenic organisms in your food. The stomach is protected by a mucous layer and then the bulldog-like enzymes (activated by acid) are turned loose on the food to chew it up to microscopic pieces for later absorption in the small intestine.
For people with low acid production, Betaine-HCL or apple cider vinegar actually improves their digestion and reflux symptoms. Also gluten-avoidance (which acts as a sticky glue-like substance in the digestive system) can help improve the efficiency of digestion and eliminate reflux symptoms.
When the acid is low or not present (due to PPI medication) or due to lack of acid production - there is poor activation of the digestive enzymes - and poor digestion. So again, what you end up with is slow digestion, poor nutrient absorption, and undigested food being pushed through your bowels. This is why PPI medications now have a FDA warning on them about magnesium deficiency, osteoporosis, and B12 deficiency. Read Drug Muggers for a full description of the problems.
See the FDA alerts about PPI medications:
The other problem I see time and time again is from drinking water - especially cold water - DURING meals. Restaurants around the U.S. always give you that nice big glass of ice water at the beginning of the meal and it is considered an insult to not keep that glass of ice water topped off during your meal. Enzyme activity is significantly impaired by cold temperatures. Also enzymes are diluted by the water and not able to work at full concentration when they finally encounter the food in the stomach. So again, there is slow digestion, more reflux, impaired nutrient extraction, and undigested food being shoved through the bowels to create more pathogenic bacterial overgrowth. In many countries around the world, water IS NOT served at meals and if it is served at meals, it certainly IS NOT ice water.
Water is very important for our bodies. We generally need about 1.5 to 2.5 liters a day of good clean water. Water should be consumed BETWEEN meals as not to disrupt the digestion process. Unfortunately, restaurant food is so heavily salted that we have a very strong craving for water during meals out at restaurants. Ask them if they can use less salt on your food - or just avoid heavily salted dishes. If you have limited options - resist the urge to drink water until the end of your meal. And skip the ice.
One final problem with water during meals is that our stomach really has a limited volume. When that volume is maxed out, then pressure is placed on the lower esophageal sphincter (valve), and it is told to open (to prevent too much pressure in the stomach). This causes reflux. Large meals invariable cause more reflux. Now, when you add water to the picture, you further increase the volume in the stomach and further increase the chance for reflux. Keep the stomach volumes low by eating slowly, eating smaller portions, and avoid excess water during meals.
3. Enzymes. There are many people that lack enzymes or have low levels of enzymes for digesting some or many foods. Beano is a classic example of enzyme replacement. Some people get gas and bloating after eating beans. This is due to a difficulty in digesting certain plant based materials given a lack of enzyme activity to fully digest those substances. Some animals have no problem eating grass or tree bark because they have enzymes to digest these, human do not and must eat more selectively. Some people have enzyme deficiencies which cause lactose intolerance. Taking enzymes to help with digestion of lactose helps prevent gas, bloating, and diarrhea. Ice-cream is sometimes even worse (since it is cold and inhibits enzymes even further for those individuals). Raw cow's milk is often tolerated by lactose-intolerant individuals because the enzymes are still found in the cows milk and are "turned on" by the acid in your stomach. Raw cow's milk (and human breast milk) was designed for the baby who might not have all the enzymes active in their digestive system. Unfortunately, pasteurization kills these enzymes.
If there are signs of enzyme deficiencies, then it is very important first to think about if you have sufficient acid to activate your digestive enzymes. After that is addressed, you can start thinking about replacing those enzymes. Omega-Zyme is one good enzyme replacement product. Many times it is possible to be more selective about enzyme replacement by listening to your body's response to particular foods. Physicians sometimes use products like Creon for patients that have exocrine pancreatic insufficiency.
4. Gut microbiome. The bacteria in your gut can be both good and bad. Often when your diet or digestion is poor, you feed and strengthen the bad bacteria (excess sugar feeds the pathogenic bacteria). Many physicians will recommend probiotics to help with a bacterial imbalance. However, it is important to keep in mind the scale of the problem. We have a bucket full of bacteria in our gut. A small probiotic capsule is very small compared to our large volume of gut bacteria. If we are feeding the unhealthy bacteria too much, we cause competition that places our expensive probiotic at a significant disadvantage. It is therefore important to fix the "fertilizer" or the PREbiotics going to feed the gut microbiome at the same time as fixing the balance of bacteria with PRObiotics. Genova has a nice test that helps to identify your gut microbiome diversity - GI Effects. Genova's NutrEval also indirectly looks at markers of intestinal dysbiosis and can be helpful in identifying a problem.
"The average child in the United States will receive between and 10 and 20 courses of antibiotics by the time he or she is 18 years old."
So, in summary, all of these areas have to be working well for good digestion and good "extraction" to take place. Chew your food well. Avoid acid suppressors and fix reflux problem with lifestyle changes. Avoid water during meals, especially cold water. Consider acid or enzyme replacement if there are symptoms of poor digestion. Work on cultivating healthy gut bacteria and starving out the unhealthy gut bacteria.