For the past decade, gluten has been one of the most polarizing topics in the health and food worlds. Many health practitioners are only now beginning to recognize and validate the spectrum of symptoms and diseases associated with gluten. At the same time, many people working in the restaurant industry continue to view the consumer demand for gluten-free foods as an annoying fad that will pass. However, the trend has not passed and diagnosis of gluten-related issues continues to rise. Why?
Gluten is a protein component of several grains including wheat, barley, and rye. Wheat (and therefore gluten) is ubiquitous in the Western food supply because it’s easy to grow, is a good source of calories, is relatively high in protein, and it can be stored whole or processed into an enormous array of products. Especially during times of food scarcity, wheat helped ensure entire populations did not starve. In the U.S., wheat is a subsidized crop making it artificially cheap for food manufacturers to use as an ingredient. So for many people, consuming a diet full of highly processed wheat products feels like an economic necessity. Although wheat may help prevent hunger and starvation, the gluten protein it contains can contribute to other unintended health consequences.
One of the reasons some individuals struggle with gluten is that it is difficult to completely digest, especially when in flour form (e.g., breads, cereal, pastries). Many processed wheat products are made with extra gluten (it provides structure to baked goods), as well as other additives such as enzymes and preservatives that may further impair digestion. Although many people have no noticeable symptoms of incomplete digestion, it does not mean digestion and nutrient absorption is functioning properly. The challenging digestibility of wheat and an over-reliance on wheat in our food supply are likely partial catalysts in the epidemic of gluten-related illnesses and poor gut health.
Current research proves that gluten is a critical factor in gut health and functioning. The gliadin fraction of the gluten protein is the only dietary substance known to trigger release of a gut mucosal hormone called zonulin. (Biotoxins from opportunistic gut bacteria are the other known exogenous triggers for zonulin release.) Zonulin regulates the opening of tight junctions in the small and large intestinal mucosa, dramatically impacting the permeability of the gut. Both the amount of zonulin release and tight junction responsiveness to zonulin differs dramatically between individuals, likely due to genetic variation and exposure to environmental factors (stress, exercise, toxins, etc.). When tight junctions are opened by zonulin, larger-sized particles in the gastrointestinal tract that are not supposed to leave the gut are able to do so. Depending on a person’s susceptibility and immune system status, these larger particles may be problematic, potentially leading to immune system activation, food allergies, and other autoimmune diseases. It is important to recognize that research has shown wide variation in individual responsiveness to the gliadin protein and subsequent zonulin release. Therefore, dietary gliadin, gut bacterial composition, genetic susceptibility, and environment all factor into a person’s zonulin secretion and tight junction regulation. The interplay between those factors (and undoubtedly others) creates a spectrum of reactivity to gliadin with extremely responsive individuals sometimes developing celiac disease (CD).
Celiac disease is an immune-mediated inflammatory reaction to the gliadin protein. Ingestion or exposure to gliadin results in an immune response with substantial intestinal inflammation, nutrient malabsorption, large releases of zonulin, and opening of tight junctions. The inflammatory response eventually leads to intestinal scaring and increased risk for gastrointestinal cancers. The only current treatment for individuals with CD is complete avoidance of gliadin which allows for normalization of the immune response and alleviation of CD symptoms.
I believe what we are seeing with increasing rates of CD, food allergies, autoimmune diseases (including type 1 diabetes), and people reporting gluten sensitivity, is that the respective roles of diet, genetics, gut microflora, and the environment in tight junction regulation are changing. In the past genetics likely played the largest role with relatively few people developing CD and autoimmune diseases. I speculate, however, that the combination of the standard American diet (with its high gluten and low nutrient content), compromised gut microflora, and other environmental triggers has primed many individuals to be more reactive to zonulin than in previous generations.
Translating all of this information into dietary recommendations is not straightforward. I don’t believe there is sufficient evidence (yet) to categorically recommend avoidance of gluten to everyone (there are many reputable practitioners who believe otherwise). However, there is clear evidence of gluten’s role in compromised intestinal permeability, systemic inflammation, and generalized gastrointestinal problems (gas, bloating, constipation, diarrhea, etc.). Of course, an exacerbating issue is that the largest source of gluten in the Western diet is not from unprocessed forms of wheat, barley, or rye, but from highly processed (often sugar-laden, and nutrient-devoid) food products such as shelf-stable cereals, breads, pastas, crackers, pretzels and other baked goods. Regardless of their gluten content, these “foods” shouldn’t be the foundation of any diet.
I believe a healthy disease-free person should focus on consuming whole foods (vegetables, healthy fats, nuts, seeds, eggs, unprocessed meat and dairy, fruit, legumes, and unprocessed grains) without particular worry about gluten content. Coincidentally, by focusing on whole foods, gluten content almost certainly decreases while other health-promoting qualities of the diet increase. But if you already consume a whole foods based diet and are curious about exploring how you feel on a gluten-free diet, there’s nothing wrong with giving it a try — you might find it beneficial. For the large and growing number of individuals with diseases or symptoms linked to increased intestinal permeability (aka, leaky-gut) or who are concerned about gastrointestinal functioning, switching to a gluten-free, whole-food based diet is a reasonable and achievable step toward improving health.
Personally, I follow a gluten-free diet most of the time and have for several years. My choice to be mostly gluten-free is partly because of convenience (my partner is gluten-sensitive), and partly for personal health. I love cooking for our family and cooking gluten-free is no more difficult than any other type of cooking, it just requires a little more knowledge about food composition. (Note: the recipes on this site are all gluten-free.) While I don’t have any noticeable physical reaction to gluten, I find the science showing it’s negative roles in gut health and systemic inflammation, convincing. Since gut functioning and low systemic inflammation are both vital to optimal health, I choose to consume foods that are gut-friendly and anti-inflammatory. However, I don’t obsess over being gluten-free. Unless my health status changes or the research showing ill effects of gluten becomes conclusive, I’ll continue to enjoy an occasional slice of sourdough, a pint of craft beer, or a perfectly made croissant.