Unless you’ve been living under a rock for the past several years, you are well aware that gluten has become something of a villain in the food and nutrition arena. This little protein that is found in several grains has been blamed for everything from rashes, indigestion, and even unwanted fat gain. This has led to a push from many health advocates to eliminate gluten from the diet. Doing so, in their view, would lead to better health, weight loss, and a generally more enjoyable life.
This all sounds like a great deal on the surface. Just avoid gluten and you become the picture of health. The bad news is that gluten is found in a lot of the most common and highly enjoyable foods. Bread, pasta, cereals, baked goods, and even most beers contain gluten, hence why most people are pretty hesitant to give up eating gluten. However, even though these health experts give plausible reasons for avoiding gluten, can we really trust their rationale? Is gluten really as bad for your health as they make it out to be? Looking into the science, we see that gluten can have either a really bad or totally neutral impact on your health. The key is figuring out which category you fall into.
Why is Gluten Villainized?
The exact reason that gluten began receiving a bad rap isn’t completely known. It could have started as a simple association between gluten containing foods and weight gain. After all, gluten is found in many high carbohydrate foods. Although it has changed over the years, carbohydrates have most recently been blamed for the obesity epidemic we face today. However, the villainization of gluten most likely gained momentum because of the rise in Celiac Disease cases.
Celiac Disease is an autoimmune issue in which the body attacks and destroys the intestinal villi of the small intestine [1]. This autoimmune reaction happens in response to the ingestion of gluten. The villi essentially get filed down little by little the more that the small intestine is exposed to gluten. This causes some serious digestive issues given the fact that those villi serve to move the intestinal contents through the small intestine. Left untreated, the person can experience severe pain, diarrhea, nutrient malabsorption/deficiency, and even the development of additional autoimmune diseases.
As is the case with some new diseases, Celiac Disease has become rather sensationalized in recent times. After hearing about the disease, many people assume that they too have an issue with gluten in their diet. This happens despite the fact that only 1 in every 100 people has Celiac Disease in the US [1]. Perhaps they cut out gluten and notice some weight loss. Or perhaps the placebo effect caused them to feel better with a gluten free diet. Whatever the case, being gluten free has become synonymous with superior health and wellness.
Gut Permeability for All?
Interestingly, many experts assert that the issues with gluten may extend beyond just Celiac Disease alone. Several doctors have written books that have attempted to explain the potential health disrupting potential of gluten. The main argument against the ingestion of gluten for non-diseased folks is the aspect of gut permeability. These experts assert that gluten increases gut permeability by opening the tight junctions of the intestinal lining. Our tight junctions are supposed to stay closed in order to prevent any large molecules from passing into circulation. If these junctions are opened and molecules leak through the gut, many health complications are possible due to inflammation and autoimmunity. But are their claims really based in truth?
Research into this matter has revealed an interesting phenomenon. Upon the exposure to gluten, a protein in the intestines called zonulin is upregulated [5]. This protein regulates the tight junctions in the small intestines. The more zonulin that is present, the wider the gap in the tight junctions becomes [5]. Based on this observation, it is theoretically true that gluten could cause gut permeability and thus health complications. However, just because gluten upregulates zonulin production doesn’t mean it will lead to increased gut permeability. We still have to examine the extent to which zonulin is upregulated.
In order to evaluate this relationship, researchers exposed ex vivo intestinal cells and layers to gluten/gliadin [3]. In addition, they used both non-celiac disease samples as well as celiac disease samples. What they found is that both celiac and non-celiac cells responded to the exposure by increasing zonulin production. However, this response was significantly larger in celiac disease samples compared to non-celiac disease samples. In addition, the permeability of these cells was impacted significantly greater in celiac samples.
Interestingly, there was still an increase in permeability in non-diseased samples that reached significance. This certainly opens the door just slightly to the possibility of gluten being harmful. But before we make that jump, we have to remember that this was done ex vivo. That means that these results can’t be generalized to what would happen in vivo. In other words, we can’t be sure that this is how the intestinal cells would respond under normal conditions inside the human body. More research is certainly needed, but this does provide some guidance on where to go.
Considering Other Stressors
Even though the results we discussed above need to be taken with a grain of salt, let’s indulge for a moment. If we take the permeability results at face value, it is plausible to say that gluten could cause some issues. Over time, these small increases in permeability could add up and perhaps get worse. In fact, that is something we see with autoimmune disorders. Research has shown that autoimmune disorders are brought about in part by permeability in the gut [4]. However, other factors also need to be present in order for gut permeability to lead to autoimmune dysfunction.
In order to develop autoimmune dysfunction, an individual must be “genetically predisposed” to this phenomenon. Specifically, different polymorphisms of the Human Leukocyte Antigen (HLA) have been linked to autoimmune issues [2]. If you express a certain polymorphism of the HLA gene, you have a higher likelihood of developing autoimmunity. Theoretically, repeated exposure to gluten and other stressors would increase the likelihood of autoimmune disease by increasing gut permeability. However, it isn’t necessarily a sure thing that this will happen. In fact, exposure to gluten alone is probably not enough to cause an issue unless you are predisposed to Celiac Disease.
However, you may want to consider the fact that gluten isn’t the only stressor we encounter. There may be other foodstuffs or additives that can cause a similar increase in gut permeability. Similarly, our system can become overstressed through exposure to heavy metals, environmental toxins, and the like. Combine these stressors and you have a storm brewing that could potentially lead to issues over time. This is yet another reason why it is crucial for us to take care of our health in many different ways. In other words, we need to eat well, exercise adequately, and get enough sleep if we want to be robust to these nutritional and environmental stressors.
Conclusion
In today’s nutrition climate, gluten represents one of the more misunderstood topics. So many health and fitness bloggers and experts advocate a gluten free lifestyle. Their intentions are usually pure-hearted, but they may not always be based in scientific fact. If you are someone who suffers from Celiac Disease, then gluten is absolutely harmful for your health. However, the prevalence of Celiac Disease is not as high as most people think.
For those who don’t suffer from Celiac Disease, gluten seems to have a small impact on gut permeability. This is another reason that some will advocate for a gluten free diet. However, the rise in gut permeability may not be very significant for normal, healthy individuals. Additionally, this relationship with gut permeability has yet to be proven with in vivo clinical trials. Therefore, those with healthy and robust immune systems are probably safe to eat gluten in moderation. So make sure you are taking care of yourself on all fronts if you want to enjoy that slice of bread or stack of pancakes from time to time!
References
- https://celiac.org/celiac-disease/understanding-celiac-disease-2/celiacdiseasesymptoms/4
- Cruz-Tapias, P., Castiblanco, J. and Anaya, J.M., 2013. HLA association with autoimmune diseases.
- Drago, S., El Asmar, R., Di Pierro, M., Grazia Clemente, M., Sapone, A.T.A., Thakar, M., Iacono, G., Carroccio, A., D’Agate, C., Not, T. and Zampini, L., 2006. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scandinavian journal of gastroenterology, 41(4), pp.408-419.
- Fasano, A., 2012. Leaky gut and autoimmune diseases. Clinical reviews in allergy & immunology, 42(1), pp.71-78.
- Fasano, A., 2012. Zonulin, regulation of tight junctions, and autoimmune diseases. Annals of the New York Academy of Sciences, 1258(1), pp.25-33.
