First, let’s differenciate between Celiac Disease (a gluten allergy) and Gluten Sensitivity
Celiac disease, or a gluten allergy, is characterized by villous atrophy or presence of endomysial antibodies (EMA), anti-tissue transglutaminase antibodies (tTG) and deamidated gliadin peptide antibodies (DGP-AGA) (1). Gluten sensitive people are not diagnosed with celiacs because they lack these key characteristics.
But, gluten sensitive people can test positive to anti-gliadin antibodies (AGA) or they can test positive to only one of the CD associated antibodies. Super confusing, right?! This indicates that more research needs to be done on how to diagnose people with a sensitivity to gluten (2). So far, the only way to know if someone has a gluten sensitivity is by removing the food completely followed by a re-introduction period.
It is estimated that gluten sensitivity occurs six times more than celiac disease!
How can gluten sensitivity and Celiac Disease affect the brain?
This is a super hot topic with about 162 articles connecting CD and gluten sensitivity to neurological and psychiatric disorders.
Research has not been able to seperate CD and GS in these studies but both are related to increased risk of depression, anxiety, epilepsy, ADHD and neurological disorders. About 22% of patients diagnosed with celiac disease develop some psychological or neurological disorder later in life (3). This may be due to possible cross contamination and accidental gluten exposure.
A 2019 systematic review on non-celiac gluten sensitivity (NCGS) found that the symptoms of gluten sensitivity are closely related to irritable bowel syndrome and Crohn’s disease (4). This indicates that individuals with NCGS might suffer from gut dysbiosis and other gastrointestinal problems which is associated with increased brain-related disorders.
Zonulin is a protein synthesized by our liver and intestinal cells that plays a key role in modulating the tight junctions in our intestinal lining. Too much Zonulin can cause these tight junctions to open in the gut. If these tight junkies are open, it is known as “leaky gut” which can cause an inflammatory response throughout your body and affect your brain function.
Studies have shown that when intestinal cells are exposed to gluten, zonulin is produced. People diagnosed with celiacs disease have higher levels of zonulin and intestinal permeability compared to individuals with NCGS (5).
Too much zonulin production can lead to increased intestinal permeability which can be measured through fecal secretory IgA secretion. A research study found that the most powerful stimulators for zonulin secretion is gluten and bacterial exposure. In addition to these, genetics, exposure to environmental triggers, immune response variations (adaptive VS innate) and intestinal barrier function are also important factors resulting in zonulin secretion (6).
Does this mean I should avoid gluten to have a healthy nervous system?
Not necessarily. If you do suffer from depression, anxiety, epilepsy, or ADHD, I highly recommend getting tested for Celiac disease (a simple blood or stool test from your doctor or functional medicine dietitian (like me!). If you test negative for celiac, I would still try a six week gluten elimination to see if symptoms improve. This will rule out any gluten sensitivity that could be bringing you down!
1.Volta U, Tovoli F, Cicola R, et al. Serological tests in gluten sensitivity (nonceliac gluten intolerance). Journal of clinical gastroenterology. https://www.ncbi.nlm.nih.gov/pubmed/22138844. Published September 2012. Accessed September 9, 2019.
2. Briani C, Zara G, Alaedini A, Grassivaro F, Ruggero S, Toffanin E, et al. Neurological complications of celiac disease and autoimmune mechanisms: A prospective study. Journal of Neuroimmunology. 2008;195:171–175.
3. Jackson JR, Eaton WW, Cascella NG, Fasano A, Kelly DL. Neurologic and psychiatric manifestations of celiac disease and gluten sensitivity. Psychiatr Q. 2012;83(1):91–102. doi:10.1007/s11126-011-9186-y
4. Roszkowska A, Pawlicka M, Mroczek A, Bałabuszek K, Nieradko-Iwanicka B. Non-Celiac Gluten Sensitivity: A Review. Medicina (Kaunas, Lithuania). https://www.ncbi.nlm.nih.gov/pubmed/31142014. Published May 28, 2019. Accessed September 9, 2019.
5. Drago S, El Asmar R, Di Pierro M, et al. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scandinavian journal of gastroenterology. https://www.ncbi.nlm.nih.gov/pubmed/16635908. Published April 2006. Accessed September 9, 2019.
6. Fasano A. NYAS Publications. The New York Academy of Sciences. https://nyaspubs.onlinelibrary.wiley.com/doi/full/10.1111/j.1749-6632.2012.06538.x. Published June 25, 2012. Accessed September 9, 2019.