Breaking down gluten
Gluten has become a controversial topic in the nutrition world, with many people choosing to avoid it despite not having celiac disease. While some dismiss gluten-free diets as a fad, emerging research suggests that gluten avoidance may have biochemical benefits for gut health, inflammation, and overall well-being—even for those without diagnosed gluten intolerance. Let's dive into the science behind it.
Gluten can increase intestinal permeability (leaky gut)
Gluten, a protein found in wheat, rye, and barley, contains gliadin, which has been shown to stimulate the release of zonulin—a protein that regulates intestinal tight junctions.
Increased zonulin levels lead to the loosening of tight junctions in the gut lining, making the intestines more permeable (Fasano, 2020).
A more permeable gut allows undigested food particles, toxins, and bacteria to enter the bloodstream, triggering immune responses and systemic inflammation (Fasano et al., 2011).
Even in non-celiac individuals, gluten has been shown to transiently increase gut permeability, which may contribute to digestive discomfort and inflammation.
Gluten can trigger systemic inflammation
For individuals with gluten sensitivity, leaky gut or other underlying conditions, gluten consumption can trigger an inflammatory immune response.
When gliadin passes through the gut lining, it can activate pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β, which contribute to chronic inflammation (Hollon et al., 2015).
Chronic low-grade inflammation has been linked to conditions such as autoimmune diseases, arthritis, cardiovascular disease, and neuroinflammation (Vojdani, 2020).
Reducing gluten intake may help lower systemic inflammation and improve symptoms in people with inflammatory conditions.
Gluten and neurological health: The gut-brain connection
The gut and brain are closely linked via the gut-brain axis, and gluten may impact brain function in multiple ways:
Gluten-derived exorphins (gluteomorphins) can bind to opioid receptors in the brain, potentially affecting mood, cognition, and cravings (Kostovcik et al., 2017).
Increased intestinal permeability can lead to neuroinflammation, which has been implicated in conditions like anxiety, depression, and even neurodegenerative diseases (Celiac Disease Foundation, 2023).
Some individuals with non-celiac gluten sensitivity (NCGS) report brain fog, fatigue, and mood disturbances after consuming gluten (Ludvigsson et al., 2021).
For those experiencing cognitive issues, reducing gluten may improve mental clarity, focus, and overall brain function.
Digestive issues and gluten sensitivity
Even in non-celiac individuals, gluten can contribute to digestive discomfort:
Bloating, gas, and irregular bowel movements are common symptoms of non-celiac gluten sensitivity (NCGS) (Catassi et al., 2015).
Gluten-containing grains also contain FODMAPs, which can be poorly absorbed and fermented in the gut, leading to IBS-like symptoms (Gibson & Shepherd, 2010).
People with IBS, bloating, or unexplained digestive issues may experience relief by eliminating gluten.
Gluten and Autoimmune Diseases
Gluten has been linked to multiple autoimmune conditions, beyond just celiac disease:
Molecular mimicry: The immune system may mistakenly attack the body’s own tissues due to structural similarities between gluten proteins and human proteins (Vojdani, 2020).
Conditions like Hashimoto’s thyroiditis, rheumatoid arthritis, and type 1 diabetes have been associated with gluten sensitivity and increased gut permeability (Fasano, 2020).
For individuals with autoimmune diseases, avoiding gluten may help reduce immune activation and flare-ups.
Should you avoid gluten then?
The biochemistry of gluten reveals that it can affect gut permeability, immune response, inflammation, and brain function—even in individuals without celiac disease. If you suspect gluten may be affecting your health, an elimination diet followed by a careful reintroduction may help determine your sensitivity. If sensitive, find alternatives to gluten.
References:
Catassi, C., et al. (2015). Non-celiac gluten sensitivity: The new frontier of gluten-related disorders. Nutrients, 7(6), 4966–4975.
Celiac Disease Foundation. (2023). Gluten and the gut-brain connection. Retrieved from Celiac.org.
Fasano, A. (2020). All disease begins in the (leaky) gut: Role of zonulin in autoimmune diseases. Nature Reviews Gastroenterology & Hepatology, 17(2), 77–88.
Fasano, A., et al. (2011). Zonulin, regulation of tight junctions, and autoimmune diseases. Annals of the New York Academy of Sciences, 1258(1), 34-44.
Gibson, P. R., & Shepherd, S. J. (2010). Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. Journal of Gastroenterology and Hepatology, 25(2), 252–258.
Hollon, J., et al. (2015). Effect of gliadin on gut permeability in individuals with and without celiac disease. Gastroenterology, 148(4), 881-889.
Kostovcik, M., et al. (2017). Gluten exorphins and their impact on the gut-brain axis: A review. Frontiers in Neuroscience, 11, 424.
Ludvigsson, J. F., et al. (2021). Non-celiac gluten sensitivity and mental health: Systematic review and meta-analysis. World Journal of Gastroenterology, 27(15), 1564–1578.
Vojdani, A. (2020). Molecular mimicry as a mechanism for autoimmune diseases. Journal of Autoimmunity, 107, 102357.
