From Dr. Houston:
Food intake, considered a pleasure by most, also represents a health hazard in situations where metabolism is altered or if food proteins are recognized as harmful by the immune system. In the latter case, IgG, IgE and IgA antibodies are produced by the immune system in response to the food "attack". The number of food-allergic patients is increasing, as is the severity of the reactions. The effects range from mild rashes, diarrhea, and/or migraine headaches to all-out systemic dysfunction.
One of the functions of the digestive tract is to change food into a substance that won't trigger the immune system to launch an attack.
Several methods are used in the body to accomplish this task. Stomach acid denatures food proteins. Denaturation removes the "glue" holding the structure of the food protein together and often results in loss of any function associated with the protein.
However, even denatured proteins can be allergenic. The next and most definitive step for rendering food proteins harmless is enzymatic degradation that begins in the stomach but predominates in the small intestine. Denaturation actually sets up the protein for optimal break down by protease enzymes.
The immune system in the gut is triggered by a number of factors but size of the offending protein is the most predominant. The larger the protein, the more likely it is to set off the alarm for IgG antibody production. Conversely, smaller proteins or fragments are able to slip under the radar for immunity activation. Research from several labs demonstrate that when protein digestion is compromised, antibody production to that food protein increases.1-3
A compromised digestive system can occur easier than one may think.
The simple act of taking an antacid reduces the activity of pepsin, the major protease enzyme in the stomach, by raising the pH of the stomach over 5.0. Many on H2 blockers have increased food allergy symptoms because the resulting low stomach acid fails to activate the pepsin enzyme system.
Larger food protein fragments are then passed on to the intestinal tract and have the potential to become allergens.2-4 Conversely, research indicates that pre-treatment of food proteins with protease enzymes results in a less allergenic potential.5, 6 Heating of a protein alone will not break down a food protein sufficiently, so cooking is no guarantee of...