The
Science Behind The Diet
In
order to understand how the diet works, it is important to understand
the disease process occurring in the gut or, WHY the diet works.
"We must never forget that what the patient takes beyond
his ability to digest does harm." Dr. Samuel
Gee.
The
Specific Carbohydrate Diet™ is predicated on the understanding that
Ulcerative Colitis, Crohn's Disease, Irritable Bowel Syndrome, and
gluten therapy resistant Celiac are the consequence of an overgrowth
and imbalance of intestinal microbial flora. By altering the nutrition
we take in, we can effect the constitution of our intestinal flora,
and bring it back into balance, healing our digestive tracts and
restoring proper absorption.
The intestinal tract forms a rich ecosystem, comprised of over 400 bacterial
species. Some are harmless, and others not. In the gut of a healthy person,
these various communities of microbes compete with each other for scarce nutritional
resources. Consequently, they exist in a state of balance, and the stomach
and small intestine harbour only a sparse population of microbial flora. In
the large intestine, each type inhibits an overabundance of the others, and
this prevents the waste products and toxins of a particular type of microbe
from overwhelming the body. The stomach and upper intestine are also protected
by high acidity, and the action of peristalsis.
The Vicious Cycle
When
the balance in the gut is disturbed, an overgrowth of intestinal
flora can result. Microbes migrate to the small intestine and stomach,
inhibiting
digestion and competing for nutrients. The gut then becomes overloaded with
the byproducts of their digestion. This bacterial overgrowth can be triggered
by overuse of antacids, reduced stomach acidity due to aging, weakening of
the immune system through malnutrition or poor diet, and alteration of the
microbial environment through antibiotic therapy.
The
components of our diet, particularly carbohydrates, play an enormous
role in influencing the type and number of our intestinal flora. 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. All serve to irritate
and damage the gut. There is evidence that increased acidity in the gut
due to malabsorption and fermentation of carbohydrates, may lead common
harmless
intestinal bacteria to mutate into more harmful ones. Further, lactic acid
produced during the fermentation process has been implicated in the abnormal
brain function and behaviour sometimes associated with intestinal disorders.
The overgrowth of bacteria into the small intestine triggers a worsening
cycle of gas and acid production, which further inhibits absorption and
leads to
yet more harmful byproducts of fermentation. The enzymes on the surface
of the small intestines are destroyed by the now present bacteria, and
this
further disrupts the digestion and absorption of carbohydrates, leading
to further
bacterial overgrowth. As both the microbial flora and their byproducts
damage the mucosal layer of the small intestine, it is provoked to produce
excessive
protective mucus, which further inhibits digestion and absorption.
Damage
to the mucosal layer involves injury to the microvilli of our absorptive
cells. These microvilli act as the last barrier between the nutrition
we take in and our bloodstream. As our absorption is inhibited, folic
acid
and vitamin
B12 deficiency can lead to impaired development of microvilli, while
an abnormally thick layer of mucus prevents contact between microvilli
enzymes
and the carbohydrates
we ingest. The small intestine responds to this spiraling irritation
by producing more goblet (mucus-making) cells, creating yet more
mucus. Finally,
as the
goblet cells become exhausted, the intestinal surface is laid bare, and
is further damaged, and possibly ulcerated. As more carbohydrates are
left in
the gut, they cause water and nutrients to be pulled from the body into
the colon, resulting in chronic diarrhea. Absorption is further hindered
as diarrhea
increases the rate with which food travels through the gut.
The
Diet
"The Specific Carbohydrate Diet™ is based on the principle that specifically
selected carbohydrates, requiring minimal digestive processes, are well absorbed
and leave virtually none to be used for furthering microbial overgrowth in the
intestine. As the microbial population decreases due to lack of food, its harmful
byproducts also decrease, freeing the intestinal surface of injurious substances.
No longer needing protection, the mucus-producing cells stop producing excessive
mucus, and carbohydrate digestion is improved. 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." The simpler the structure
of the carbohydrate, the more easily the body digests and absorbs it. Monosaccharides
(single molecules of glucose, fructose, or galactose) require no splitting
by digestive enzymes in order to be absorbed by the body. These are the sugars
we
rely on in the diet. They include those found in fruits, honey, some vegetables,
and in yoghurt.
Double
sugar molecules (disaccharides: lactose, sucrose, maltose and isomaltose)
and starches (polysaccharides) are primarily avoided on the diet. Some
starches have been shown to be tolerated, particularly those in the
legume family
(dried beans, lentils and split peas only). However, they must be soaked
for 10-12
hours prior to cooking, and the water discarded since it will contain other
sugars which are indigestible, but which are removed in the soaking process.
Small amounts of legumes may only be added to the diet after about three
months. The starches in all grains, corn, and potatoes must be strictly avoided.
Corn
syrup is also excluded since it contains a mixture of 'short-chain' starches.
Yoghurt
Finally, the SCD™iet relies on properly fermented yoghurt, and in some cases,
acidophilus supplements, to help repopulate the gut with healthy intestinal
flora. By increasing the population of 'good' bacteria in the gut, the
overgrowth of harmful bacteria is put in check. As the competition for
nutrition between the various strains of bacteria resumes, the variety
of intestinal flora is brought back into balance. yoghurt must be properly
prepared by fermenting it for 24 hours. This allows enough time for the
bacteria in the yoghurt culture to break down the lactose (disaccharides)
in milk, into galactose (a monosaccharide). All SCD™iet yoghurt is homemade,
as commercially available yoghurts are not properly fermented.
Originally from
the BTVC site
Web site design by Iain MacMaster
Please report any errors or comments to Iain MacMaster
Information
published on
Breaking the Vicious Cycle Web site is intended to support the book Breaking
the vicious cycle
by Elaine
Gottschall and is for information purposes only. It
is not the intention of this site to diagnose, prescribe, or replace medical
care.
Your
doctor
or nutrition expert should be consulted before undertaking
a radical change of diet.
© 2005 Breaking the Vicious Cycle
