 |
Deficiency of digestive enzymes
released into the intestine can result in poor digestion of
foods. For example, when the pancreas gland is damaged
(pancreatitis) chronically, usually from chronic alcohol abuse,
or is congenitally underdeveloped or malfunctioning (e.g. cystic
fibrosis). The pancreatic enzyme deficiency that occurs results
in malabsorption, especially for fats, that cause symptoms of
diarrhea and weight loss. Abnormal bacteria types and levels in
the gut, also known as dysbiosis, and abnormal excess levels of
“bad” bacteria or presence of bacteria in upper small intestine
where little or no bacteria normally occur (bacterial
overgrowth) can interfere with digestion, absorption or cause
fermentation of food resulting in symptoms of abdominal pain,
bloating, gas, and diarrhea.
Some foods and food additives have a
direct toxic effect on the gastrointestinal tract. Additives
such as MSG and sulfites can cause symptoms, including flushing
and diarrhea or the “Chinese restaurant” or “salad bar”
syndromes.
All foods contain proteins known
as lectins. Some of these proteins are highly resistant to
digestion and are toxic to the human intestine especially if
they are not pre-treated by soaking, cooking well, or removing
toxic portions. For example, inadequately soaked and cooked
kidney beans will cause a food poisoning like illness. There are
several foods that have lectins that are poorly tolerated by
many humans and are lethal to insects and pests.
One researcher, Loren Cordain
PhD., author of the Paleo Diet, has published extensive research
on how the human intestine is not “evolved” to tolerate many of
the foods we now eat but did not eat in the ancient
“hunter-gatherer” times resulting in many of the illness seen in
modern societies and the rising epidemic of autoimmune diseases.
Several of the “modern” foods that were not part of the ancient
diet but constitute much our diet now have well recognized toxic
or poorly tolerated proteins known as lectins. Examples include
wheat germ agglutinin (WGA), casein (cow’s milk protein), peanut
agglutinin (PNA), soyabean agglutinin (SBA) and tomato lectin
(TL) that have been shown in animal studies to be toxic to the
human gut. There are a few published studies and little active
research on the role of dietary lectins in health and disease.
When the reaction is an immune
toxicity reaction to a food protein intestinal damage commonly
results, frequently referred to as “leaky gut” because of the
symptoms of malabsorption or the entry of toxic food proteins
and/or bacterial products into the blood stream resulting in a
variety of adverse health effects. This reaction may result in
autoimmunity, the body attacking itself within the gut or
distant organs or tissues. The reaction may be aided by abnormal
bacteria types and/or levels in the gut (dysbiosis). The
symptoms commonly develop over time and flare in just hours to
up to three days after eating the offending food and continue as
the food is eaten.
Because the protein in the food
is usually the cause and such proteins may be hidden in other
foods, especially processed foods, and the toxicity is more of a
delayed and cumulative immune reaction, it is very difficult for
the person suffering from this to identify the specific food as
the cause. For example gluten (the protein in wheat) and casein
(the protein in cow’s milk) are in many foods and toxic to many
individuals. Over time people sensitive to such food proteins
typically become more ill and may develop enough intestinal
injury that blood tests for other types of antibodies, IgG
and/or IgA, to the food or specific food proteins, may be
detectable in the blood, stool or saliva.
Delayed immune response to
proteins in the food (wheat, cow’s milk) resulting in bowel
injury, gastrointestinal and non-gastrointestinal symptoms and
increased autoimmune conditions is most well recognized in
Celiac disease. It is an autoimmune disease resulting from
ingestion of gluten in wheat or products made from wheat flour
(or gluten like proteins in barley and rye). It used to be
considered a disease of children and rare, especially in the
United States. However, blood test screening studies have
documented that it is present in approximately 1 in 133 to 1
in100 people worldwide though most of those affected are
undiagnosed and untreated. It is diagnosed by positive screening
blood tests and confirmed by a characteristic abnormal small
intestine on biopsy followed by relief of symptoms and return of
the intestine to normal after a gluten-free diet. Untreated it
is associated with higher rates of cancer especially lymphoma,
osteoporosis, anemia, and other complications of malabsorption
resulting in shortened life expectancy. It is treated with a
life-long gluten free-diet. Lesser degrees of gluten intolerance
or sensitivity may not be severe enough to cause abnormal or
diagnostic blood tests and intestinal biopsies but result in
symptoms that improve or resolve with a gluten-free diet and may
be detected by elevated stool or saliva antibody tests.
Though injury to the intestine
tissue may be seen visually as abnormal appearing tissue during
endoscopic procedures such findings are non-specific for the
cause. The tissue frequently appears normal and therefore many
times is not sampled by biopsy, though under the microscope
injury may be seen, though not specific for cause or food. If
the physician is either not suspecting food intolerance or
doesn’t routinely biopsy normal appearing intestinal tissue
looking for signs of food intolerance, the injury may not be
discovered.
The immune based food
intolerances are commonly associated with many symptoms that can
be both gastrointestinal and outside the gut and may include
bloating, gas, diarrhea (and sometimes constipation), abdominal
pain, nausea, fatigue, headaches, joint and muscle pains, skin
rashes, weight loss or gain, anemia or nutritional deficiencies,
irritability, depression, mental fogginess, and nerve pain
(neuropathy). These symptoms may be misdiagnosed or mislabeled
as irritable bowel syndrome, chronic fatigue syndrome, reflux,
ulcer, and fibromyalgia, etc. without another thought by patient
or physician that food intolerance may be the cause and specific
food elimination may be the cure. The common food allergens also
are the most common causes of food intolerance reactions.
Generally, most physician are
aware of common food allergy symptoms and how and when to test.
However, several studies have confirmed most people’s experience
that the majority of primary care physicians are unaware of the
common symptoms of Celiac disease, that blood tests exist for
screening antibodies and the high risk genes, and that it is
common and may be diagnosed in adults. This is why the diagnosis
is delayed on average over 11 years in most adults, after many
of them have irreversible complications such as osteoporosis,
cancer, or another autoimmune disease. The awareness and
acceptance of non-Celiac gluten sensitivity and other food
protein intolerances in the medical community is even worse.
Therefore, food intolerance or
sensitivity is commonly missed and untreated. Many patients are
forced to self-diagnose by discovery of the link of their
symptoms to specific foods serendipitously, often as a result of
an elimination diet, recommendation of an alternative
practitioner or friend/relative, or search for help on the
internet or multiple physicians for help. Hopefully, by reading
this article you now better understand food allergies and
intolerances, why they are often missed and that they are a
common cause of many symptoms, not just intestinal, that usually
improve if not resolve once the offending food or foods are
eliminated from your diet.
By Dr. Scot
Lewey
|