Specific Carbohydrate Diet (SCD) and Autism
The Specific Carbohydrate Diet was very successfully clinically tested for over 50 years by Dr. Haas and biochemist Elaine Gottschall. It was designed for patients with intestinal diseases, but has been "found" by parents of children with autism. The kids on the Specific Carbohydrate Diet are doing very well.
Gluten sensitivity and intolerance to salicylates are symptoms of a damaged digestive system which is overrun with intestinal pathogenic organisms. When the health of the digestive tract is restored, these symptoms disappear. It is better to cure the underlying causative factors than to just try to palliate the symptoms. Because the Specific Carbohydrate Diet reaches to the root cause of these problems by restoring the health of the digestive system, the Specific Carbohydrate Diet is the optimal choice for a child with ASD.
Jody Goddard reports that recent research shows more than 50% of children with autism have GI symptoms, food allergies, and maldigestion or malabsorption issues (Horvath). She says that it's obvious from talking to parents that GI problems are a major concern in children with autism. Physicians dealing with autism have discussions on GI issues all the time. Antifungal use, both prescription and alternative remedies, is a common topic. Parents have tried 'anti-yeast' diets, prescription drugs and natural remedies, but nothing seems to be 'the answer' to the chronic microbial problems their children face. Many parents wish to pursue chelation for their children, but are unable to do so because of their inability to get their children's gut pathogens under control.
Altered intestinal permeability was found in 43% of autistic patients, but not found in any of the controls (Harvard University). Intestinal permeability, commonly called leaky gut, means that there are larger than normal spaces present between the cells of the gut wall. When these large spaces exist in the small intestine, it allows undigested food and other toxins to enter the blood stream. When incompletely broken down foods enter the body, the immune system mounts an attack against the 'foreigner' resulting in food allergies and sensitivities. The release of antibodies triggers inflammatory reactions when the foods are eaten again. The chronic inflammation lowers IgA levels. Sufficient levels of IgA are needed to protect the intestinal tract from clostridia and yeast. The decreasing IgA levels allow for even further microbe proliferation in the intestinal tract. Vitamin and mineral deficiencies are also found due to the leaky gut problem.
An example of the problems created by the vitamin deficiencies that occur within a leaky gut is Vitamin B12 deficiency. B12 absorption is inhibited early in this process as microbes enter the small intestine because B12 is absorbed in the ileum (last section of the small intestine). Vitamin B12 is essential for metabolism of fats and carbohydrates and the synthesis of proteins. Vitamin B12 is involved in the manufacture of the myelin sheath, a fatty layer which insulates nerves in the brain. It is also essential for the formation of neurotransmitters. A compound known as intrinsic factor, which is secreted by the cells lining the stomach, is necessary for the absorption of vitamin B12. (The New Encyclopedia of Vitamins, Minerals, Supplements, & Herbs). Another important function of B12 is repairing damaged, flattened microvilli. With sufficient B12 and folic acid in the bloodstream, the intestinal cells and microvilli can rejuvenate every 3-4 days.
In a healthy digestive system, the small intestine and stomach are not inhabited by bacteria. When the intestinal flora balance in the colon is lost, the microbes can migrate into the small intestine and stomach, which interferes with digestion. The microbes compete for nutrients and their waste products overrun the intestinal tract. One of the toxins produced by yeast is actually an enzyme that allows the yeast to bore into the intestinal wall. The yeast also produce other toxins such as organic acids, which can also damage the lining of the intestinal wall.
Bacterial overgrowth in the small intestine destroys enzymes on the intestinal cell surface, which prevents carbohydrate digestion and absorption. The last stage of carbohydrate digestion takes place at the minute projections called microvilli. Complex carbohydrates that have been broken down by the enzymes embedded in the microvilli can be absorbed properly and enter the blood stream. But when the microvilli are damaged, the last stage of digestion cannot take place. At this point only monosaccharides can be absorbed because of their single molecule structure.
In the small intestine, the body should absorb the nutrients needed from what is eaten, however, in the case of malabsorption, the undigested carbohydrates left in the small intestine cause the body to draw water into the intestinal tract. This pushes the undigested carbohydrates into the colon where the microbes can thrive on it. This allows for even further proliferation of the unwanted microbes and continued increase in problems of malabsorption.
Low intestinal carbohydrate digestive enzyme activity was found in 43% of patients with autism. (Horvath) Recent studies point out that ongoing carbohydrate malabsorption keeps the digestive system constantly weakened, leading to systemic disorders. Suspected carbohydrate malabsorption should be treated to ward off further damage to the body's digestive system.
Most intestinal microbes require carbohydrates for energy. The Specific Carbohydrate Diet limits the availability of carbohydrates. By depriving these microbes of their food source, they gradually decrease in number. As the number of microbes decreases so do the toxic by-products they create.
The Specific Carbohydrate Diet (SCD) is intended to stop the vicious cycle of malabsorption and microbe overgrowth by removing the source of energy from the microbes. The SCD allows simple monosaccharides that do not need to be broken down in order to be absorbed.
By following the Specific Carbohydrate Diet (SCD), malabsorption is replaced with proper absorption. Inflammation is decreased and the immune system can return to normal. Once the immune system is returned to adequate levels, it can begin to keep in the intestines microbes in proper balance.
The Specific Carbohydrate Diet (SCD) allows simple carbohydrates, but prohibits complex carbohydrates. The SCD is started by following an introductory diet, which consists of a limited selection of foods. After the introductory diet advised on the Specific Carbohydrate Diet, the next stage of the diet allows many more foods, but requires that all fruits and vegetables be peeled, seeded and cooked in order to make them more easily digested. Raw fruits, vegetables, nuts and seeds are added to the diet later. To properly follow this diet, it is very important to read 'Breaking the Vicious Cycle'by Elaine Gottschall. The book details the progression of allowed foods as well as providing many delicious recipes.
The Specific Carbohydrate Diet (SCD) is the only diet that targets the malabsorption issues that are so prevalent in children with Autism. By removing the foods that cannot be properly broken down, the energy source for the unwanted gut pathogens is eliminated. With their food source taken away, the microbes die off and the proper gut flora balance can be restored. The vicious cycle of malabsorption, inflammation and food allergies seen in children with autism is broken and healthy digestion can begin.
The Specific Carbohydrate Diet (SCD) is a scientific diet based on chemistry, biology and clinical studies. It is detailed in the book, Breaking the Vicious Cycle, written by Elaine Gottschall, M.Sc..
The selection of foods that are allowed on the Specific Carbohydrate Diet is based on the chemical structure of these foods. Carbohydrates are classified by their molecular structure. The allowed carbohydrates have a molecular structure that is small enough to be transported across the surface of the small intestine into the blood stream. These carbohydrates do not need to be broken down by various processes of the digestive organs such as the pancreas or the intestinal cell surface enzymes.
In order to effectively implement the Specific Carbohyrdate Diet, it is necessary to read Breaking the Vicious Cycle. The Specific Carbohydrate Diet is not merely one of substituting one group of foods for another. The diet begins with a limited number of foods and gradually adds more foods as the intestinal tract heals.
When the diseased intestines are inflamed from the effects of dysbiosis, they cannot break down the molecules that are too large to be transported across the small intestinal surface into the bloostream. Instead of entering the bloodstream, the undigested starch and sugar molecules serve as a continual source of food for bacteria and fungi. The premise of the Specific Carbohydrate Diet (SCD) is to remove all sources of carbohydrates whose molecular structure is too large for direct entry into the bloodstream. By removing starches and sugars, dysbiosis is corrected. The result is a decrease in intestinal inflammation and healing of the intestinal tract.
The Specific Carbohydrate Diet SCD was originally developed as a diet for celiac disease. The Specific Carbohydrate Diet (SCD) is completely gluten free. Dr. Haas, the doctor who pioneered the Specific Carbohydrate Diet (SCD), spent many years investigating which foods people with celiac disease could tolerate. He found that they could tolerate lactose-free dairy products. So, certain dairy products, such as properly prepared homemade yogurt, are allowed on the Specific Carbohydrate Diet SCD. However, some of the parents of children with ASD are reluctant to try any kind of dairy products and avoid them even though they are lactose free. There are children who remain strictly casein free while following the Specific Carbohydrate Diet (SCD) and still comsume a well-balanced diet packed with needed nutrients.