The specific carbohydrate diet

  • Monosaccharides (glucose, fructose, galactose): fruit, honey, well prepared yoghurt and certain vegetables.
  • Disaccharides: sucrose (regular sugar), lactose (milk sugar), maltose (starch) and isomaltose (starch). Sucrose is broken down to glucose + fructose by the enzyme sucrase, lactose is broken down to glucose and galactose by the enzyme lactase, starch (maltose and isomaltose) is broken down to glucose + glucose by the enzyme maltase and isomaltase. Many medications, vitamin and mineral preparations contain lactose!
  • Polysaccharides (starch: amylose and amylopectin as found in vegetables and grains). The more amylopectin the harder it is to digest.

Carbohydrate metabolism and the intestinal tract

Glucose is the only sugar our body is able to burn. For this reason all sugars that end up in our body need to be converted into glucose. This can only be done with the help of enzymes that are produced by the body itself. Unlike sucrose, lactose and starch, glucose does not require any digestion and is quickly absorbed in the small intestine. Children suffering from diarrhoea develop a damaged intestinal wall which leads to a disaccharide intolerance (regular sugar). This damage of the intestinal wall causes an excessive production of mucus by the intestinal wall cells, which blocks the disaccharides from connecting with the digestive enzymes in the absorbing intestinal cells. Thus the sugars become food for all kinds of bacteria which leads to an unbalanced intestinal flora. These bacteria produce waste products that are absorbed into the bloodstream and are toxic for the body. As a rule the stomach and the upper part of the small intestine are home to smaller amounts of intestinal bacteria than the last part of the small intestine and the colon. Excessive bacterial growth of stomach and small intestine may be caused by acid blockers, undernourishment or malnutrition accompanied by a failing immune system, old age and last but not least the use of antibiotics that enable bacteria to mutate. This overpopulation of bacteria in the stomach and small intestine can endanger the absorption of vitamin B12. Additionally it leads to increased gas production and fermentation products that maintain malabsorption and intestinal disorder. Likewise the intestinal wall forms a thick layer of mucus to defend itself against the aggressive intestinal content which in turn increases malabsorption. An additional problem is that yeasts, bacteria and parasites having entered the small intestine cause damage to the intestinal wall and thus destroy the important enzymes. Lactase is the first enzyme to be affected in this way. This explains why there are so many problems with milk and dairy products because these cannot be digested without lactase. When the situation becomes more serious there is the possibility of infection and ulceration of the intestine that are known as serious disorders: Crohn's disease, colitis ulcerosa, celiac, diverticulitis and chronic diarrhoea. All these problems can be tackled by depriving these bacteria of their source of nutrition with the help of the Specific Carbohydrate Diet. Bacteria feed on undigested sugars that remain in the intestine and that in turn are converted into gasses and acids (D-lactate) and other microbial by-products. These acids in the small intestine damage the intestinal wall and cause abnormal brain activity and behavior because they travel to the brain via the blood. Likewise the nervous system and brain can be affected by the malabsorption of vitamins and minerals. Thus these intestinal disorders may cause epilepsy, schizophrenia, confusion, aggression, disorientation, blurred vision, poor judgment, offensive behavior, indistinct speech, unsteady gait, rolling of the eyes, amnesia and eccentric behavior. For the sake of completeness, it should be noted that digestion largely depends on the digestive fluids of the pancreas. Fiber is an important filler product that retains a sufficient amount of water in the intestine to prevent the stool from becoming too hard and dry. Fiber is not digested in the intestine!

Specific carbohydrate diet or gluten-free

The SCD basically originates from the start of the last century and was developed by Dr. John Howland for celiac disorder. Dr. Haas continued it's development and concluded after treating 600 celiac patients: "We see complete cures without any relapse, no death tolls, no crises, no lung problems or growth inhibition." (1949). But shortly hereafter a group of faculty members of the departments of pharmacy, pediatrics and youth health sciences of the University of Birmingham, after conducting a study of just ten children, reached the conclusion that the celiac disorder was not caused by the carbohydrates in the grain but rather by the gluten protein in the flour of rye and wheat. Much later it was discovered not to be an actual gluten allergy but rather a sealing of the carbohydrates by the gluten which partly hinders the digestion of the carbohydrates. When the gluten is removed and subsequently added to the flour, digestive problems do not occur. Likewise the diagnostic method also came to a halt because mainly biopsies were used as the diagnostic method as apposed to addressing the typical symptoms. This led to a large group not being diagnosed properly even though people did have disorder symptoms. Additionally, the gluten-free diet does not alleviate the patient of other serious intestinal problems that do not classify as typical celiac symptoms. The Specific Carbohydrate Diet on the other hand is effective on a much broader level.

Intestinal disorders and the brain

As early as 1908 it was concluded that some patients who suffered from prolonged diarrhoea and malabsorption also showed degeneration of the brain, the spinal cord and other nerve tissues. It was proven that paralytic symptoms and various psychiatric disorders were caused by malnutrition which in turn was caused by malabsorption due to intestinal illness and the production of toxins affecting the normal function of the brain. In the seventies and eighties it was discovered that patients who were less able to break down and absorb nutrition due to a partial removal of the small intestine, often developed neurological symptoms such as aggression, sudden disorientation, blurred vision, poor judgment, offensive behavior, slurred speech, unsteady gait with small steps, rolling of the eyes, confusion and delirium.

Intestinal disorders and autism

The SCD sees the digestive problem in autistic children as a disturbance in the bacterial fermentation process and its consequent problems:

  1. The production of enormous amounts of volatile short-chain fatty acids (organic acids, e.g. D-Lactate).
  2. Reduction of pH value (acidity level) of the blood by the absorption of these acids.
  3. Excessive bacterial growth of undigested carbohydrates in the end of the small intestine and the colon.
  4. Mutation (change) of bacteria by the acids or antibiotics.
  5. Production of toxins by diseasing bacteria.

According to the Pfeiffer Institute 85% of all autistic children suffer from digestive disorders. A research study involving 400 autistic children conducted by Harvard General Hospital showed that 55% suffered from a lactase deficiency and 15% from a lactase and disaccharide deficiency. Additionally they proved that the digestion of carbohydrates is obstructed at the position of the absorbing intestinal cell. All this forms the basic principle of the SCD: preventing disaccharides from entering the intestine.