在1950年代，哈斯（Haas）给一个名叫朱迪·戈特绍（Judy Gottschall）的年轻女孩治病，他患有严重的溃疡性结肠炎。朱迪从加州大学（UC）稳定康复后，她的母亲伊莱恩·戈特绍尔（Elaine Gottschall）回到了学校，全心投入研究饮食和食物对肠道的影响。她在47岁时获得了生物学，营养生物化学和细胞生物学学位。1987年，她出版了《食物与内脏反应》（Food and the Gut Reaction），并于1994年作为SCD的权威文章《打破恶性循环-通过饮食使肠道健康》（Breaking the Vicious Cycle – Intestinal health through diet）重新出版。
A BEGINNERS GUIDE TO SCD
The specific carbohydrate diet (SCD) is an elimination diet that is grain free, starch free, sugar free and avoids most dairy (except for hard, aged cheese and homemade yogurt that has been fermented for over 24 hours.) The SCD focuses on natural, nutrient rich foods that includes vegetables, low-sugar fruits, eggs, meats and nuts. Essentially, the specific carbohydrate diet is very similar to what our ancestors ate.
The origins of the SCD can be traced back over a hundred years when early Coeliac disease researchers recognised that their patients did better when they removed grains from their diet. At the time, all starches (not just ‘gluten’) were singled out. In the late 1920’s, Dr. Sidney Hass, a paediatrician in New York, took the findings and experimented with diet as a therapy for his young patients. By simply excluding specific carbohydrates, Haas claimed to cure children of Coeliac disease and other gut conditions, such as inflammatory bowel disease.
In the 1950’s, Haas was treating a young girl by the name of Judy Gottschall, who was very sick with Ulcerative Colitis. After Judy’s steady recovery from UC, her mother, Elaine Gottschall, returned to study so that she could dedicated her life to researching the diet and the effects of food on the gut. At 47 she had earned degrees in biology, nutritional biochemistry, and cellular biology. In 1987, she published ‘Food and the Gut Reaction’, which was republished in 1994 as definitive SCD text “Breaking the Vicious Cycle – Intestinal health through diet”.
Advocates of the SCD quickly followed in her footsteps to spread the word of its efficacy; creating cookbooks and recipe websites for others to benefit from. Gottschall’s book and ongoing research continues to inspire people in the dietary management of inflammatory bowel disease, Coeliac disease and other gastrointestinal diseases.
Foods on the SCD are classified by their chemical structure – either monosaccharide, disaccharide, or polysaccharide. On the diet, only monosaccharide carbohydrates are permitted. Disaccharides include lactose, sucrose, maltose, and isomaltose and white sugar. Polysaccharides and are found in grains, starches and starchy veggies.
“These allowed carbohydrates are monosaccharides and have a single molecule structure that allow them to be easily absorbed by the intestine wall. ‘Complex carbohydrates’ which are disaccharides (double molecules) and polysaccharides (chain molecules) are not allowed. Complex carbohydrates that are not easily digested, feed harmful bacteria in our intestines causing them to overgrow producing by-products and inflaming the intestine wall. The diet works by starving out these bacteria and restoring the balance of bacteria in our gut.”
Not everyone’s digestive tract has evolved to optimally digest some modern food sources. So when complex carbohydrates, refined sugar and other synthetic ingredients found in our diet are removed from the diet of these people, digestive processes improve, toxins are reduced, inflammation subsides and overall health improves.
SCD AND THE MICROBIOME
The rationale behind the SCD diet is that many digestive disorders stem from “an overgrowth and imbalance of intestinal microbial flora”. In other words, there are too many harmful types of bacteria, yeast and fungus residing within the body (mostly within the gut) where the majority of the immune system is located. Elaine Gottschall explains,
“When carbohydrates are not fully digested and absorbed, they remain in our gut, and become nutrition for the microbes we host. The microbes themselves must digest these unused carbohydrates, and they do this through the process of fermentation. The waste products of fermentation are gases, such as methane, carbon dioxide & hydrogen, and both lactic & acetic acids, as well as toxins and all serve to irritate and damage the gut.”
Foods allowed on the diet are easily digested and absorbed by the body and leave little behind for bad bacteria to enjoy.
“As the microbial population decreases due to lack of food, its harmful by-products also decrease, freeing the intestinal surface of injurious substances. Malabsorption is replaced by absorption. As the individual absorbs energy and nutrients, all the cells in the body are properly nourished, including the cells of the immune system, which then can assist in overcoming the microbial invasion.”
In this way, the SCD targets both the underlying problems within the digestive tract that can lead to serious disorders as well as symptoms related to inflammation, bacterial overgrowth and poor nutrient absorption.
BENEFIT FROM THE SCD
The SCD is most often recommended to people with Coeliac disease, inflammatory bowel diseases (such as Crohns disease, ulcerative colitis) and diverticulitis. If you don’t have a diagnosable digestive disorder but suffer from persistent irritable bowel syndrome symptoms (like constipation, diarrhoea, gas, bloating) or food sensitivities, the SCD diet can also help. Simply removing hard to digest carbohydrates will help lower fermentation in the gut which leads to these symptoms. In turn, the diet will help prevent gut permeability (leaky gut) which could lead to more serious health issues down the track. More recently, it’s even been suggested that the SCD can help with learning disabilities such as autism.