Food intolerance is not the same as food allergy. With an allergy, the immune system is triggered.
For example, a peanut allergy is a true allergy.
With a food intolerance, your body just doesn't digest a particular food properly. Sometimes this
is obvious, for example in Celiac Disease, where gluten can't be digested. Many people are lactose
intolerance, meaning they lack the enzyme to digest milk sugar.
These examples are well-understood and therefore accepted by the Western medical establishment. But
there may be other more subtle food intolerances. For example, many people think the underlying cause of
all autoimmune disease (not just IBD) is the profound change in diet that occurred when humans shifted
from a hunter-gatherer society (Paleolithic) to an agricultural society (Neolithic) about 10,000 years ago.
One reason I'm convinced by this is so many separate threads of evidence converge to give the same advice
for different reasons. Many different experts recommend that people suffering from IBD eliminating some or all
of the foods introduced with agriculture: grain, beans, milk products, and refined sugar. Some say not to eat
grain because it's composed of a particular type of polysaccaride. Some say not to eat grain because it
contains insoluble fiber, which is generally bad for people with bowel disease. Some say not to eat grain
because it contains lectins that confuse the body's immune system (see below for details). They all have
different reasons, but they all say the same thing.
You see a similar phenomenon with milk products. Should you avoid milk because it's mucous-causing, because
many people have mild lactose intolerance and don't realize it, or because we did not evolve drinking the
milk of other animals? Does it matter? Many experts give the same advice for different reasons.
Some people have reported that eliminating these foods from their diets led to long-term remissions.
I can't say that happened with me. Maybe, for some people, once the damage is done you need extra measures
to reverse it.
How Diet Can Trigger Autoimmune Response
Loren Cordain, a professor at Colorado State University in Ft. Collins, Colorado, wrote a fascinating
article about why and how eating grains and beans can cause autoimmune disease (references below).
Here's a brief synopsis.
Both grains and beans are very high in lectins. Lectins have both a carbohydrate and a protein component.
The carb component lets them adhere to body cells. The protein component is very similar to the proteins in
the human body. This phenomenon, called molecular mimicry, evolved to protect plants from insect
predators. Other plants have lectins, but not in the amounts found in grains and beans.
Lectins can cause leaky gut syndrome. When the lectins escape the bowel, they are attacked by the immune
system. The protein structure is remembered by the immune system, as always happens when the immune system
responds so it can be more efficient the next time the danger is encountered.
Unfortunately, in some people,
the immune system can get confused by the similarity between the lectin protein and the proteins in the self.
Depending on the person's genetic predisposition (all autoimmune disease is caused by a combination of
genetic predisposition and environmental triggers), the immune system will then attack the colon (causing
inflammatory bowel disease), the nerve tissue (leading to multiple sclerosis), etc.
Cordain suggests that not ingesting foods very high in lectins (specifically, grains and beans) will prevent
the constant triggering of the autoimmue response, thus allowing remission.
Grains and Legumes: Biochemical Evidence of their Evolutionary Discordance
The Awful Truth About Eating Grains
Cereal grains: humanity’s double edged sword. World Rev Nutr Diet 1999; 84:19-73. (#22 in the list of articles)