Cross Reactivity: When Gluten-Free is Not Enough
Oct 18, 2013 01:21AM
● By Betty Murray
Betty Murray, CN, CHC
When the body creates antibodies against gluten, those same antibodies also recognize proteins in other foods. When we eat those foods, even though they don’t contain gluten, the body may react as if we just ate gluten. So we may be doing a fantastic job of remaining completely gluten-free, but still launch an immune response, exhibit symptoms and feel bad.
Proteins are found in all foods. Gliadin (gluten) is a chain of amino acids in a specific sequence, and it is the specific sequence of these amino acids that determines what kind of protein is formed. Then these amino acid chains are folded, which gives a protein its structure. The folding is integral to the function of the protein.
An antibody is a Y-shaped protein produced by immune cells in the body. Each tip of the Y contains the region of the antibody that can bind to a specific sequence of amino acids that bind with receptors on the protein structure. Think of it like a lock (protein) and key (antibody). The formation of antibodies against a protein depends on the sequences of amino acids in that protein and how is folded. Certain amino acid sequences in proteins, like gliadin, are more likely to be the target of new antibody formation than others simply because of the location of the protein sequence. This is also part of why certain foods have a higher potential to cause allergies and sensitivities.
In that case, the amino acid sequence that an antibody recognizes in gliadin is also present in another protein from another food. There are 20 different single amino acids and millions of ways to link these amino acid together to form a protein structure. The gliadin string of amino acids and protein structure is similar enough in structure and amino acid sequence to other foods that the body may also attach the anti-gliadin antibody to a protein from another food.
In recent studies, anti-gliadin antibodies did cross-react with all dairy, including whole milk and isolated dairy proteins (whey, casein, casomorphin and butyrophilin). This may explain the high frequency of dairy sensitivities in gluten sensitive patients. Oats, brewer/baker’s yeast, instant coffee (but not fresh coffee), milk chocolate (attributable to the dairy proteins in chocolate), sorghum, millet, corn, rice and potato all have been cited in reviewed studies to cross-react with anti-gliadin antibodies.
While not all people with gluten sensitivities will also be sensitive to all of these foods, they should be highlighted as high risk for stimulating the immune system, just like gluten does. Because these are commonly used ingredients in commercial gluten-free baked goods, caution should be exercised if individuals are still experiencing symptoms. They may do well to remove these foods, as well, if they are simply not seeing the improvements hoped for by eating gluten free.
We have the choice of either cutting these foods out of our diet and seeing if we improve; and we can now get tested for cross-reactive foods to see if our body produces antibodies against these foods.
Betty Murray, CN, CHC, is a certified nutritionist, health coach, author of Cleanse: Detox Your Body, Mind and Spirit and found of Living Well Dallas, an integrative medical center in Dallas. Contact her at 972-930-0260 or [email protected].