In their raw, whole, unprocessed state all foods contains the enzymes needed to digest themselves. Unfortunately cooking destroys food enzymes and the body is forced to rely on its own digestive enzymes. In fact exposing food to sustained dry heat above 160 degrees or wet heat above 117 is enough to destroy enzymes. When the body has to produce its own digestive enzymes for food it has to divert its limited enzyme capacity from creating metabolic enzymes. This leaves fewer enzymes available for vital bodily processes. Having to waste precious enzyme resources in this manner will weaken health and shorten life.
Since the whole point of eating healthy food is to improve and sustain health it is rather silly to destroy its very life giving elements. It also makes little sense to overwork the digestive system and use up more energy than is necessary for digestion. An inefficient digestive system that negatively impacts metabolism can create the same problems as malnutrition as for all intents and purposes it results in the body getting less nutrition. A simple tour of the digestive system as it digests cooked, enzyme deficient food will help illustrate this.
The mouth is the beginning of the digestive system
Digestion begins from the moment food enters the mouth. Starch is the first part of food to undergo digestion. Chewing food breaks it down into smaller pieces and mixes it with saliva. Saliva contains the enzyme ptyalin, an amylase or carbohydrate digesting enzyme that breaks down the complex sugars of starch into simple sugars. Once food is swallowed it reaches the first part of the stomach, the cardiac section. No gastric juice or enzymes are secreted here nor is there any peristalsis, the muscular contractions that move food through the stomach. This part of the stomach is essentially an enzyme stomach that allows any exogenous or external enzymes from food to function without impediment.
The Stomach is a Multistage Digestive Organ
The stomach is filled and emptied layer by layer. It does not mix food together uniformly like a blender. As each layer moves down through the stomach it is subjected to the next stage of digestion. The entire digestive process serves to liquify food into a pulpy mass or chyme.
The middle part of the stomach, the fundic section, secretes the protein digesting enzyme pepsin as well as gastric juice. The gastric juice collects in the bottom or pyloric section of the stomach, slowly increasing in acidity to digest protein. Pepsin will not function in the fundic section as it is not acidic enough. Ptyalin can function here and will continue to do so until the stomach becomes acidic enough to digest protein. Starch will buffer it, for a time, from the increasing acidity. Then it will become inactive until the pH levels are again favorable to it.
The lower portion, pyloric section, of the stomach begins protein digestion from pepsin. It can take several hours for protein to digest. In fact under highly unfavorable circumstances it can remain in the stomach much longer.
Fat, if not accompanied by its own or supplemental lipase enzymes, does not undergo digestion in the stomach. It is only when it reaches the duodenum that lipase enzymes will be secreted. Although stomach acid will serve to emulsify fat somewhat it isn't until bile is released in the duodenum until its digestion begins. The presence of fat in the stomach will slow down peristalsis, effectively slowing down digestion. For protein this allows more time for digestion. For starch it will help slow the release of sugars and help stabilize blood sugar. Too much fat however can bog down digestion and possibly insulate food from stomach acid making it harder to digest.
The duodenum is the next stage of digestion
In the duodenum bile is secreted to emulsify fat while sodium bicarbonate is secreted to neutralize gastric acid. Pancreatic enzymes are secreted to continue digestion into the small intestine. While enzymes are secreted for protein, starch and fat they are not released all at once. Enzymes are first secreted for the macronutrient of greatest concentration. The pancreas only secretes one class of enzyme at a time as it has only one duct connecting it the duodenum. Digestive enzymes are not secreted in equal amounts as was once believed. The body does not waste enzymes by manufacturing more than are needed. It also does not produce as many enzymes for fat as it does for protein and starch. Food is released slowly into the small intestine which minimizes how much undigested food makes its way through.
The small intestine continues what stopped in the stomach
Once in the small intestine pancreatic enzymes begin to function. Likewise, ptyalin enzymes left over from the mouth reactivate. Protein is eventually broken down into base amino acids, fat into globules and then split into fatty acids, starch into simple sugars. The small villi of the small intestine will absorb the nutrition released from digestion. It is possible for undigested food particles to be absorbed into the blood. This can cause a host of different reactions including allergies and inflammation. Efficient digestion, friendly intestinal flora and a healthy intestinal tract can greatly mitigate allergies. The beneficial flora in the intestinal tract are important for dealing with bad digestion or other undesirable visitors.
This should help illustrate how much extra resources and energy the body has to expend to digest food by using its own digestive enzymes. It is also important to understand that the more the body has to rely on its own digestive enzymes the less resources it will have to create metabolic enzymes. In fact the dietary practice of food combining builds on the understanding of the physiology of digestion.
Sources for this article include:
The Complete Book of Food Combining: A New, Easy-to-Use Guide to the Most Successful Diet Ever by Kathryn Marsden
Enzyme Nutrition: The Food Enzyme Concept by Dr. Edward Howell
Healing with Whole Foods: Asian Traditions and Modern Nutrition by Paul Pitchford
The Food Combining Bible by Jan Dries & Inge Dries
