The gluten we eat today isn’t the same as the gluten our parents ate when they were kids. Even if not technically genetically modified, gluten has been significantly hybridized and deamidated over the years, processes that have rendered it inflammatory to humans. Unlike genetic modification, which inserts or deletes genes, hybridization creates a new protein by combining different strains of wheat. The hybridization of wheat has created a ‘new wheat’ that appears more prone to trigger immune reactions, especially in the brain and nervous system. Deamidation, which is used extensively in the food processing industry, has also made gluten more immune reactive. (Deamidation uses acids or enzymes to make gluten water soluble so it mixes more easily with other foods.) These processes appear to have played a role in the sharp increases of gluten sensitivity and celiac disease we’ve seen over the years, and numerous studies have confirmed that gluten is a major contributor to inflammation, degeneration and even autoimmunity of the brain and nervous system.
Gluten sensitivity impacts more than your gut
The basic understanding for years and still held by many today is that only a few people with certain gene types are susceptible to celiac disease and that the destruction caused by gluten is limited to the intestinal tract. But studies today challenge these concepts. First, the HLA-DQ2 and HLA-DQ8 celiac genotypes are very limited and cannot be used as sole determinants of gluten sensitivity or celiac disease. Many people who don’t have the genotypes still have severe reactions to gluten.
Second, many people with gluten sensitivity have silent celiac disease, meaning their symptoms aren’t intestinal. Instead, they react to gluten in the brain, thyroid, joints, skin or other tissues, referred to as extraintestinal manifestations. The most common non-intestinal manifestation of gluten sensitivity is in the brain and nervous system. In fact, one study of patients who manifested gluten sensitivity in the brain found only a third of them also suffered from GI disorders. Research shows gluten sensitivity not associated with celiac disease or gut damage can nevertheless solely and directly harm the brain and nervous system, leading to a number of different neurological problems.
Many doctors today aren’t trained to identify gluten sensitivity and are still stuck on outdated and limited models of celiac disease diagnosis. If your brain isn’t working well or you have a neurological disease, you should get tested for the entire spectrum of gluten sensitivity and not just the limited markers for celiac.
How gluten works against the brain
If your brain isn’t working, a sensitivity to gluten could be causing an immune assault on your brain and creating brain inflammation. Three main mechanisms appear to cause gluten to assault the nervous system.
The first is related to cross-reactivity, where the immune system mistakes one protein for another. The protein structure of gluten is similar to protein structures in the nervous system. When you’re sensitive to gluten the immune system produces gluten antibodies to tag it for destruction, but because of this similarity the immune system can accidentally produce antibodies to nervous tissue whenever you eat gluten. In this case, a gluten sensitivity may create an autoimmune attack against the brain or other parts of the nervous system thanks to cross-reactivity. (An immune response to self-tissue is called autoimmunity.) Researchers have found gluten cross-reactivity leading to autoimmunity with synapsin, a family of proteins located on neurons that help regulate neurotransmitter release; the cerebellum, which can cause issues with balance, vertigo, or motor control; and an enzyme found in the brain called glutamic acid decarboxylase (GAD), which may cause symptoms related to anxiety.
Gluten can also trigger an immune response against transglutaminase. Transglutaminases are enzymes that help bind proteins together and are also involved in the digestion of wheat. A form of transglutaminase called transglutaminase-6 (TG-6) is found throughout the central nervous system. Elevated antibodies to transglutaminase-6 indicates an immune response from gluten against the nervous system. (Classic celiac disease is associated with antibody elevations of transglutaminase-2, which indicates a reaction against the intestinal tract.)
The third mechanism is that immune reactions to gluten can break down the blood brain barrier and lead to what is called leaky brain. Your brain is protected by a filter that separates it from your circulating blood. Like the intestinal lining, this blood brain barrier is composed of ‘tight junctions’ between cells that open to selectively permit molecules necessary for neural function into the brain. Zonulin is a protein that opens up the tight junctions, thus regulating how permeable the blood brain barrier is. For people with celiac gluten triggers zonulin to open these junctions. (Importantly, many researchers believe zonulin release isn’t specific to the celiac population - some research suggests that gluten opens these junctions in all people.) A leaky brain promotes neuroinflammation and can allow in pathogens that increase the risk of autoimmune reactions in the brain and nervous system.
Going gluten free
Going gluten free can be as simple as avoiding wheat and processed foods, eating a diet of vegetables, fruits, fish and meats, and using gluten free condiments. It may take several weeks or even months for the immune response to gluten to calm down, which is why cheating or small exposures can really set you back. If you’ve been on a diligent gluten free diet and haven’t seen any improvements, you may have intestinal permeability and/or your immune system may have developed a cross-reactivity to foods with protein structures similar to those in gluten (such as milk and corn). The other main issue with going on a gluten free diet is that many people begin eating more of other grains, such as corn, rice or quinoa, and develop sensitivities to these grains. If you’re gluten sensitive and have been on a strict gluten free diet with minimal results, you may be sensitive to other grains.
Finally, don’t forget these commonly overlooked sources of gluten:
- Beer and malt extract
- Deli meats (transglutaminase is also used by the food processing industry to tenderize meat and as an additive to hold processed meats together in distinct shapes)
- Soy sauce
- Imitation crab meat
- Modified food starch
- Food emulsifiers and stabilizers
- Artificial food coloring
- Clarifying agents in some red wines