How Poor Digestion Leads to Disease

The importance of foods and digestion to human health cannot be over-emphasized!!

The entire human body - atoms, molecules, cells, tissues and organs - is made from food, water and air. Every nerve, muscle, gland, secretion, bone and hair begins as food we eat, water we drink or air we breathe. 

Everything that makes up our body originated outside of it. Water and air - simple molecules universal to all life - are absorbed into the body unchanged. Foods, on the other hand, consist of complex substances that differ from one species to another and even from one member of a species to another member of the same species. 

Foods carry the potential for building optimally functioning - healthy - bodies, but they must first be transformed by digestion. If undigested foods were to enter our bloodstream, serious illness would result. Undigested foods are incompatible with the body and with health. Our digestive system turns the food material that we eat and drink into material compatible to our body, from which our body and our health can then be built. 

After digestion transforms the foods we eat into compatible components, the body absorbs these components and uses them as building blocks to construct the molecules, cells and tissues that are the human body. 

When digestion fails to effectively transform foods into its small, compatible, health-building body construction materials, incompatible (undigested) food molecules may be absorbed. These interfere with the co-operative succession of events vital to the harmony of health. They may create social disharmony on the molecular level by stealing electrons. Molecular fragments known as free radicals result. The body’s defenses, organized by the immune system, come out to neutralize these free radicals. If the first defenses are insufficient, the immune system steps up its activities and complex molecular events take place that we experience as acute and chronic disease, and/or allergies. 

Protected Access 

Everything we eat and drink enters the body through our digestive system. Before foods are given access into the body, they have to pass certain barriers that protect the body from harm by substances not conducive to the maintenance of health. This barrier is not perfect - especially when dealing with synthetic substances that were not part of the natural system within which human digestion developed - but provides relatively effective protection against the entrance of foreign materials. 

The digestive barrier allows passage of small components of foods, components that are building blocks for the construction of all organisms - one-celled, plant and animal. Easy access to the body is given to vitamins, essential and other amino acids, essential and other fatty acids, glycerol, glucose and other simple sugars, minerals with their electrical charges neutralized (by chelation with amino acids), purine and pyrimidine bases from which genetic material is constructed and other simple, natural molecules. 

Most of the foods we eat are not consumed in the form of simple food components. They are large, complex, often-giant, super-molecules of proteins, starches and other polysaccharides and nucleic acid polymers specific to the organism of whose body they were a part. 

Dismantle and Reassemble 

To convert these complex molecules into simple, absorbable ones, nature evolved the process of digestion. During this process, complex molecules from the one-celled organisms, plants and animals that serve as our foods are systematically dismantled into the building blocks common to all life forms. We absorb these building blocks and, inside our bodies, we re-assemble them in our own unique fashion to make our own super-molecules of “us-specific” proteins, genetic material, and complex carbohydrates and so on. Every species of animal, in its digestion, follows a similar process with whatever species of plant or animal is its food. 

Through this remarkable invention of nature - digestion (dismantling), absorption and re-synthesis (reassembly) - the bodies of potatoes, carrots, and fish serve as the basis for their own transformation into human bodies. Every organism, as food for other organisms, suffers the same glorious transformation. 

While the sloppy and misleading statement “You are what you eat!” has hurt the credibility of the natural foods industry - you don’t become a pea by eating peas or a pig by eating pork - our bodies are made from what we eat, and our foods do carry the construction materials for human bodies. 


Foods supply the energy necessary to maintain life and the building blocks necessary for the construction of the body. Yet foods are useless for both these purposes until many enzymes and chemicals in the digestive tract have acted upon them. 


Digestion - the conversion of foods into smaller components (nutrients) that the body can use - is the first set of steps in a complex process that transforms a grain, a vegetable, a fish or a salad into skin, bones, muscle, blood, and nerves. 

During digestion, stomach acid and protein-digesting enzymes (proteases) break down proteins into amino acids. Fat-digesting enzymes (lipases) break fats and oils into fatty acids, monoglycerides, and glycerol. Carbohydrate-digesting enzymes (carbohydrates) break starch, glycogen, malts, syrups, dextrin and other polysaccharides into simple sugars. Other enzymes break down DNA and RNA into their components (nucleotides: purines and pyrimidines; sugars: ribose and deoxyribose; and phosphate). Still other enzymes break cholesterol esters into their components - cholesterol and fatty acids. 

Good digestion, necessary for good health, has to take place before efficient absorption is possible. Incomplete digestion causes many problems, including poor absorption of nutrients, a nutrient-starved body prone to deficiency symptoms and infection, intestinal fermentation of undigested materials, intestinal gas and toxin production and absorption of undigested materials leading to food sensitivities, allergies and immune reactions. 

A complete lack of digestion would make absorption of the building blocks necessary for the construction of human bodies impossible. 

From digested foods, the body draws nutrients into itself. It uses these nutrients to build, maintain, repair and replace molecules, cells and tissues. Nutritious foods, well digested and efficiently absorbed, provide the basis of radiant health. 

Poor absorption of food components results in a body deficient in building materials. Cells and tissues deteriorate. Digestive enzymes and stomach acid, that the body makes from the building blocks that it absorbs, may become insufficient, making for poor digestion, further decreasing the quantity of nutrients available for absorption, in a vicious circle. Poor absorption therefore leads to poor health. 

The efficiency of digestion and absorption decreases as we age. 


Once the building blocks for body construction have been absorbed into the body, the body reassembles these building blocks into complex molecules again. Each person’s unique hereditary material (DNA) provides precise supervision for the construction of molecules, cells, tissues and organs, made exactly according to the specifications of its own unique master plan. 

A plant’s DNA specifies that it always uses its building materials to make that kind of plant. A fish or chicken uses the same building materials, but always produces a fish or a chicken. A human being’s DNA always uses the same materials to design and build a human body. The same kinds of building blocks create plants, fish, birds, mammals and humans. 

DNA is also responsible for differences between individuals. The DNA of each individual carries that person’s unique and individual master plan. During the process of development and continuously throughout life, this master plan serves as the template for making blueprints of RNA and these blueprints determine the exact sequences of amino acids that make up the structural proteins and enzyme proteins of each individual’s body structure; eye, hair, skin color, metabolic rate, biochemical uniqueness and the features that we call “inherited” traits, that pass from parents to children as family resemblances. 

The complexities of these processes are awe-inspiring to observe and contemplate. Even more remarkable is the precision of the process of development. With attention to each minute detail, atom by atom and molecule by molecule, each individual develops according to the DNA master plan carried by the chromosomes, using the components of digested foods as building materials.

The components of digestion, absorption and re-synthesis allow each organism to use another organism as its food and, by means of these processes, to reassemble the component parts of that organism into itself.


A continuous muscular tube, the human digestive system includes mouth, esophagus, stomach, intestine and anus. We sub-divide the intestine into duodenum, small intestine consisting of jejunum and ileum and large intestine or colon. Each part of the digestive tract performs a different set of functions important to health.


Diagram A-1
Human Digestive System

                                                        human digestive system

The Process of Digestion 

When the process of digestion is working properly, it breaks down complex molecules into simple ones that the body can readily absorb (assimilate). The body then uses these simple molecules to produce energy and to build its own unique molecules. These provide the vitality and the form of human health. Valves, which are rings of muscular material and the muscles in the walls of the tube, regulate the speed at which the progressively more digested food material moves down the tube. Muscular contractions mix and move food through the digestive system. Various chemicals and enzymes introduced at various points along the tract perform the specific digestive functions necessary to digest foods into components that the body can absorb.


The body’s need for building materials creates the feeling of hunger that signals us to eat. Digestion begins in the mouth. Chewing, (mastication) the first digestive process, grinds larger pieces of food into smaller particles. It moistens food with saliva and thoroughly mixes the broken food, increasing its surface area to the action of enzymes throughout the entire digestive tract. An enzyme present in salvia (amylase) begins the breakdown of starch into glucose while food is still in our mouth. The action of this enzyme explains why, if we chew a starchy food for a long time, it begins to taste sweet.


Chewed food is swallowed, entering the esophagus in which the muscular contractions of peristalsis begin. Peristalsis, a downward moving alternate constriction and relaxation of muscle, kneads the food material and propels it along the digestive tract in rhythmic waves. Three or four seconds after swallowing, the swallowed material passes through the cardia valve, into the stomach. The ardia valve is a ring-like valve that separates the esophagus from the stomach and prevents material in the stomach from being regurgitated into the esophagus.


The stomach is a J-shaped hollow muscular organ of the gastrointestinal tract which lies between the esophagus and the duodenum, on the left side of the abdominal cavity. The stomach is involved in the second phase of digestion following mastication. The stomach is a highly acidic environment due to hydrochloric acid secretion which produces a luminal pH range usually between 1 and 2. Combined with digestive enzymes, this acid stomach environment is able to break down large molecules from food to smaller ones so they can be absorbed from the small intestine.


Several alkaline secretions enter the duodenum, a U-shaped, 8 to 10 inch long section of the small intestine. These secretions change highly acidic, liquefied food material from the stomach to weakly basic. The secretions that bring about this change from acidic to basic include bile from the liver and gall bladder, pancreatic juice from the pancreas and secretions from the intestinal wall. The enzymes of the small intestine that facilitate digestion and absorption can fulfill their functions only in alkaline conditions.


Thousands of chemical transformations related to nutrition and essential to health take place in the liver. It detoxifies harmful molecules, stores several vitamins and minerals, converts carotenes to vitamin A and stores glycogen - “animal starch”- a carbohydrate that sustains blood sugar levels. The liver also metabolizes fats and produces cholesterol, enzymes and substances required for blood clotting (coagulation). The liver also produces and delivers dilute bile fluid to the gall bladder, which chemically modifies and concentrates this fluid. A fat-containing meal triggers the release of the resulting bile, a complex, concentrated alkaline fluid containing bile pigments (blood breakdown products), salts (cholesterol molecules modified to make them water-soluble), bicarbonate and other mineral electrolytes. Bile facilitates the digestion of fats and aids in efficient fat absorption into the body through the villi of the small intestine. The body eventually reabsorbs bile salts, but removes the bile pigments from the body with bowel wastes.


The pancreas, best known for secreting the hormone insulin that moves blood sugar into our cells (preventing diabetes), also produces and secretes pancreatic juice into the duodenum. Pancreatic juice contains the enzymes necessary to completely digest the liquefied, pre-digested, now alkaline food that entered the small intestine from the stomach. Protein-digesting enzymes from the pancreas include trypsinogen, chymotrypsinogen, procarboxypeptidases A&B, and proelastase. Pancreatic fat-digesting enzymes include phospholipase and triacylglyceride lipase. Pancreatic juice also contains the carbohydrate-digesting amylase and the nucleic acid-digesting deoxyribonuclease and ribonuclease enzymes.

Jejunum & Ileum

Peristalsis moves digesting food from the duodenum into the jejunum, then into the ileum; the two main parts of the small intestine. The inside lining of these parts are covered with millions of tiny, finger-like projections (villi). These increase the surface area available for contact between the small intestine and its digested food material.

Glands located at the base of the villi produce alkaline intestinal juice containing many more enzymes, mucus and electrolyte minerals. Villi, in constant expanding and shrinking motion, keep semi-liquid digested materials surrounding them in motion as well. Villi absorb amino acids and small peptides (chains of a few amino acids) derived from proteins, sugars derived from complex carbohydrates, and short-chain fatty acids derived from fats. The blood vessel network of the villi carries all these to the liver via the portal vein. Long-chain fatty acids enter the body through lymphatic channels in the villi of the small intestine.

Large Intestine

A third valve in our digestive tract, ileocaecal valve, marks the passage from the small into the large intestine. It prevents food wastes in the colon from flowing back into the ileum. Watery materials enter the colon and move, by “leisurely” peristaltic contractions, through the large intestine. The large intestine, comprised of cecum, colon, sigmoid colon, rectum and anal sphincters, contains no villi. Main functions include re-absorption of water and storage of wastes. A large number of different kinds of bacteria live in the colon. Along with indigestible and unabsorbed material, these bacteria constitute the bulk of the feces. It takes 12 to 14 hours for material entering the colon to pass out of the large intestine through the anal sphincters, two ring-like voluntary muscles terminating the digestive tract. After foods have been digested and food components absorbed into the body, remaining undigested and indigestible waste material accumulates in the colon. Its pressure produces the “gotta go” urge, that leads to the evacuation of the accumulated waste from the body.

When Things Go Wrong 

When the digestive system does not work properly, its malfunctions affect our health in many different ways. Choosing to eat foods with poor nutritional quality may result in obtaining fewer essential nutrients than the body requires for health. 

  • Inadequate chewing can result in incomplete digestion, failure to absorb some of the nutrients that foods contain, intestinal fermentation, gas and toxin production that affect colon health. Some of these toxins may be absorbed and stress the liver, kidneys and immune system. 
  • Lack of stomach acid can result in inadequate protein digestion, inability to absorb vitamin B-12 and intestinal putrefaction with generation of toxins that may be absorbed into the body, and could also affect colon health. 
  • Lack of digestive enzymes results in incomplete digestion, putrefaction, decreased absorption of essential nutrients and internal toxin production which increases the load on kidneys, liver and immune system. 
  • Inadequate liver function can result in difficulties in assimilating nutrients, especially fats. Nausea, or a heavy tired feeling after fat-containing meals, is an indication of deficient liver function. If liver function is weak, detoxification processes for which it is responsible may be deficient, leading to negative effects on every cell, tissue and organ, allowing toxins to accumulate throughout the body. 
  • Pancreatic insufficiency leads to seriously impaired digestion that affects the entire intestinal tract, mal-absorption, which leads to deficiency of essential nutrients in the body and lowered vitality of all cells and tissues. 

Nutrient absorption tends to decrease with age because, like all ageing cells, absorptive cells become less efficient in their functions as we age. If nutrient content of our foods is deficient, the absorption difficulties are magnified, because malnourished, aging cells are even less able to do their job. 

Supplementation of the diet with essential nutrients, enzymes, fiber, herbs and other substances can contribute to significant improvements in health in many of these situations. 


Foods Build Bodies 

The entire human body is made from foods, water and air. Every molecule within the body must come from these sources. Foods must provide the building blocks essential for building a human body. If foods contain these building blocks in appropriate quantities, the body built from them functions the way nature designed it to - with energy, with vitality, without trouble. Such a body rarely breaks down.

This natural state - human health - results from consuming the necessary quantities of essential nutrients, completely digesting the sources that contain these essential nutrients, efficiently absorbing the nutrients and properly utilizing them in the body.

From Before Birth

The unborn child depends on the foods the mother eats for the nutrients to build its body. The suckling newborn also depends for all of its nutrient requirements on what its mother eats, digests and absorbs. If during her pregnancy, the mother’s absorbs all of the essential nutrients in optimum quantities, the child is likely to be born healthy, to develop with few problems and set-backs and to thrive.

Later, the individual’s state of health depends largely on the nutrient content in their own food choices and their own body’s ability to digest and absorb the nutrients these foods contain. Parents' nutritional knowledge and practices in the home play an important role in the health of their children, and help to teach good (or bad) nutritional habits that will last a lifetime and be passed on in turn to future generations.

Health is also affected by stress and other lifestyle factors. These, too, are learned and taught.

Essential Nutrients 

To build a normally functioning body, foods must contain appropriate quantities of about 50 essential nutrients. These are substances that the body cannot make, substances its cells must have to live and to function normally (be healthy), substances that it must therefore obtain from foods, food concentrates or supplements.

The essential nutrients include 22 or 23 minerals, 13 vitamins, 8 essential amino acids (10 for children; 11 for premature infants) and 2 essential fatty acids. From these, a healthy individual’s body makes other substances the body requires for healthy functioning. Individuals may derive additional benefits from a diet that includes conditionally essential and non-essential nutrients.


Deficiency of any essential nutrient can result in alteration of normal cell, tissue and body function (biochemistry), accompanied by symptoms of deteriorating health. Deficiency of each essential nutrient has its own set of deficiency symptoms. Prolonged deficiency can lead, through progressive deterioration, to death. The complete absence of any essential nutrient must result in death when the body’s stores of that nutrient are completely used up. We cannot live without essential nutrients.

Minimum Health 

The minimum amount of an essential nutrient required to prevent deficiency symptoms in a healthy person can, and has been, established. This measure, embodied by the government-set Recommended Daily Allowance (RDA), can be expected to provide an average measure of minimum health. Below this amount, symptoms of deterioration can be expected in a large percentage of the population. A large part of the population does not obtain even this minimum amount of essential nutrients from the foods they eat. The percentage of the population deficient varies for each essential nutrient.

Some essential nutrients are so common, or required in such small amounts, that deficiency is not likely to occur. Other essential nutrients may be so rare in presently eaten foods that almost 100% of the population obtains less of this nutrient than they need for maintaining optimum health.

Degenerative symptoms that accompany degenerative diseases such as heart and artery disease, cancer, and diabetes, are widespread. These three conditions kill 68% of the population. Furthermore, drugs, antibiotics and the other miracles of modern medicine - surgery, radiation, life support systems and chemotherapy - do not address the cause of these diseases and cannot cure them. Foods (nutrients) are better suited to treat and cure degenerative conditions than are medicines.

Optimum Health

How much of each nutrient would be required in a person’s diet in order to give that person the optimum amount of each essential nutrient for optimum cell, tissue and body functions (biochemical and physiological processes)? An average measure of such quantities has been proposed in the SONA (Suggested Optimum Nutritional Allowance) Study to the U. S. Senate.

SONAs are based on that long-term study carried out at the University of Alabama Medical School by Drs. Cheraskin and Ringsdorf. These doctors found that the healthiest people in their study - those who had the least signs and symptoms of disease - consumed nutritional supplements and obtained essential nutrients from foods and from supplements in daily amounts that sometimes exceeded the RDAs by a factor of 20 times. SONAs for other nutrients were also much higher than the RDAs and SONAs for a few nutrients were about equal to RDAs.

SONAs are average measures that are likely to result in improved health for a very large part of the population. But they leave some important, specific questions unanswered. Would even higher quantities of essential nutrients - such as are being taken by some individuals - have resulted in even better health than Drs. Cheraskin and Ringsdorf found in their study?

Individual Optimum 

Every individual is different in their biochemistry from other individuals and therefore differs in his or her requirement of the quantities of essential nutrients that lead to optimum cell, tissue and body function. The SONAs are an average measure of good health. Many people in the study had to consume higher quantities and many consumed smaller quantities to arrive at these average figures.

The key question that everyone must ask about their own optimum health is this: What is the daily quantity of each essential nutrient that will lead to optimum health for me? Because we are all different, this individual optimum has to be individually determined. To some extent, this determination depends on individual trial and observation.

A second key consideration in determining an individual’s optimum intake of essential nutrients is the fact that this optimum changes with activity, lifestyle, stress, age, and exposure to virus, fungus, bacteria and other factors. Because these all change over time, today’s optimum may not be optimum for tomorrow. To maintain optimum intakes under changing conditions, you need to become sensitive to your body -  learn to listen to it, to feel it, and understand what it tells you. It does let you know its needs - through hunger and thirst, through how you feel, through how your energy levels change throughout the day with meals, the supplements you try, etc.


Just as there are deficiency symptoms from not getting enough of an essential nutrient, there are symptoms from getting too much of certain essential nutrients. Excess consumption of the oil soluble vitamins A and D is possible and does happen sometimes. Imbalances or excesses of essential nutrients can lead to sub-optimal functioning, and may lead to toxic symptoms. Essential nutrient-related toxic symptoms are rare and can be reversed by discontinuing supplementation of the nutrient(s). They are almost never life threatening or irreversible. Since 1900, there have been 4 deaths from vitamin A and D overdose. Two of these deaths were due to eating polar bear liver, which is extremely high in these two vitamins; however, that is not available to most of us.

Deaths from toxic doses of essential nutrients are extremely rare. In comparison, deaths from complications or misuse of prescription and over-the-counter drugs are epidemic: causing almost 40,000 deaths per year in Canada alone.

The danger of toxicity from an excess or imbalance of essential nutrients is also very small compared to the danger of deficiency, which affects upward of 60% of the population, may be as high as 90% and kills 68% of us through degenerative diseases.


From the viewpoint of our goal of health, reversing degenerative diseases provides powerful testimony of the medicinal value of foods. But it is even smarter to prevent degenerative conditions from occurring in the first place, by adopting preventive lifestyles and eating foods and supplements that are in alignment with the body’s requirements. (Please see our article THE CASE FOR NUTRIENT SUPPLEMENTS.)

Prevention involves a small investment of time to learn about nutrition and the human body. Compared to other professions that may require years of concentrated and specialized study, it is relatively easy to master the basics of preventive nutrition. Having been eating and living in our bodies for many years already, we have a lot of valuable information about our health. It is just a matter of formalizing much of this experiential information, and making the links to both researched and common sense information about foods and human health.

The investment of time required to master nutrition is far less than the time people spend (particularly during the second half of life) trying to find effective treatments for conditions that resulted from not taking the time to learn to live preventively earlier on.

But prevention of disease is still a negative focus. Is our goal the absence of disease, or the presence of health? Our flight from disease, based on fear of disease, could be replaced by embracing health, based on love for health.

Health is a presence. Disease is its absence. Health has components that can be identified. Disease is the result of one or more of these components being absent.

Research has identified the physical components of health, the essential nutrients, as the building blocks for making human bodies that exemplify the natural state of health, bodies that function optimally. The quality of what we eat and drink, and our level of activity, determine our health. We can enjoy health from conception to old age.

The medical model does not address degenerative conditions effectively. Its premise - that disease is a presence and health is the absence of disease - is wrong. To try to remove a degenerative condition based in the absence of essential nutrients is like trying to remove darkness - impossible.

One cannot remove something that is already not there. Darkness is the absence of light. Disease is the absence of health. Pursuing health requires us to identify and embody the components of health. Besides the essential nutrients that whole foods, food concentrates, and supplements of minerals, vitamins, essential amino acids and essential fatty acids contain, food enzymes and probiotics can also add substantially to our health. Other factors for building and maintaining health include:

  • Activity that keeps our bodies fit for life;
  • Lifestyle factors that minimize stress and maximize enjoyment;
  • Detoxification methods for the body;
  • Factors of ethics and attitude;
  • The pursuit of goals that align both with our nature and the nature of the planet;
  • The development of the habits of confidence, competence, responsibility, and care;
  • Learning to live in harmony and love, friendly to life and to living, friendly to nature and environment, and friendly to self and our planet.