As gluten-related disorders are becoming more widely recognized, we’re seeing a sharp rise in gluten-free diets. What may have once been thought of as a diet fad, or perhaps pure hypochondriacal mania, is gaining support in the medical field as the evidence builds. In fact, the research is helping to clarify the possible mechanisms behind immune mediated disorders related to food intake, allowing for the distinction to be made between food allergies, autoimmunity and food sensitivity.
There are a number of diseases that have come to be recognized as being caused by gluten. These include celiac disease, baker’s asthma, dermatitis herpetiformis and gluten ataxia as well as other non-specific symptoms that are relieved by removing gluten from the diet. What’s interesting, is that what disease develops depends not only on where the gluten ends up (eg, in the lungs for baker’s asthma or intestine for celiac disease), but also how an individual’s immune system reacts to it.
The first possible type of reaction to gluten is an allergic reaction. This occurs when a specific type of antibody (IgE) is produced in response to eating gluten or inhaling flour containing gluten. This could cause a range of symptoms including a rash/hives, a runny/itchy nose or, in more severe cases, anaphylaxis. This is similar to the immune response that happens in someone who has hayfever. The only difference is that in hayfever the perpetrator of the immune reaction is pollen as opposed to gluten. Baker’s asthma is an example of this type of reaction to gluten.
The next type of response is an autoimmune response. In this case, instead of the immune system having an allergic response with IgE antibodies, it produces IgA or IgG antibodies. This in itself isn’t really a problem. In fact it’s normal for our immune system to produce IgA antibodies to the food we eat. The problem is that the antibodies produced are reactive to a normal protein found in our body called transglutaminase. This can lead to the development of celiac disease, dermatitis herpetiformis as well as gluten ataxia. It’s not exactly clear how gluten causes this reaction, but there are known genetic factors that are involved.
The third type of reaction, known as a gluten sensitivity, is less well understood. While the specific type of immune response involved is still somewhat unclear, symptoms improve with a gluten-free diet. While this could be a placebo response (take away what someone thinks is the cause and they feel better even if it’s not really the cause), evidence doesn’t support this. Studies have been undertaken that show gluten can cause gastrointestinal symptoms without causing celiac disease. Research has also shown that about half of those individuals with gluten sensitivity share the same genetic markers as those with celiac disease.
A number of factors make gluten problematic for consumption in certain individuals. In optimal digestion, proteins are denatured by the acid in our stomach and gradually split apart and broken down by a number of enzymes throughout the gut before they are absorbed by the cells in our intestine. Individual proteins within the gluten protein complex are, however, very resistant to this process. This leaves us with relatively large portions of the protein left over to react with the immune system. Complicating this feature of the gluten protein complex is the fact that modern wheat varieties tend to contain much more gluten than the traditional varieties that have been grown for thousands of years and that wheat and gluten itself are ubiquitous in our food supply. If you also account for a certain percentage of our population having compromised digestive function as well as a genetic tendency to react to gluten, it can easily be surmised that wheat and gluten would be a problem.
Food allergies and sensitivities have long been seen as problems in the “alternative” health realm. The research behind how gluten can cause illness is giving us a window into what has long been seen and suspected clinically for a variety of foods. It is quite possible, and highly likely, that other foods are also reacting similarly in genetically predisposed individuals – meaning that an allergy is not the only type of response that can occur.
What we tend to see are a core set of foods that are most often the culprits. This is likely because we have moved away from more traditional diets with a wide variety of foods into a culture with a small group of core staple foods that are found in everything – foods like wheat, corn, soy and dairy. Not only are these foods found in everything, but they are often highly hybridized, genetically modified and/or simply processed into forms that have never occurred in nature. These factors may play a large part into how a genetic tendency or a mild sensitivity becomes a more symptomatic disease.
There is one type of food reaction that has not been discussed thus far – food intolerance. An example of this is lactose intolerance. This occurs when a digestive enzyme is lacking in the intestines. Lactase is the enzyme required to digest lactose. When this enzyme isn’t present in sufficient amounts, you end up with symptoms of lactose intolerance such as diarrhea, gas and bloating. While the above mentioned reactions – allergy, autoimmune response and sensitivity – are usually to a protein, an intolerance is more commonly to a sugar.
The various responses to gluten should be a wake-up call to the mainstream medical community to begin paying more attention to symptoms that could be related to dietary reactions. While food reactions can be difficult to recognize and diagnose, it is not an impossible task. It simply requires cooperation between the doctor and the patient – a doctor that is willing to listen and open to exploring the possibilities with a patient that is willing to modify their diet and do a little detective work on their own.
Sapone, Anna; Bai, Julio C; Ciacci, Carolina; Dolinsek, Jernej; Green, Peter HR; Hadjivassiliou, Marlos et al. (2012): Spectrum of gluten-related disorders: consensus on new nomenclature and classification. In BMC Medicine 10 (13). Available online at http://www.biomedcentral.com/1741-7015/10/13.