Could Gluten be Causing Your Brain Fog?

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Often, we associate gluten or intolerance thereof with gastrointestinal problems or digestive issues. As it turns out, gluten can also have an impact on your brain and the way you think. Have you tested negative for celiac and ruled out gluten as the problem? Take a step back. It is possible to be intolerant or sensitive to gluten without having the autoimmune disease called celiac. Both diagnoses can result in gluten-induced effects on your cognition. It should be noted that “brain fog” as referred to here, is also separate from the lesser known autoimmune condition gluten ataxia. Gluten ataxia does not affect the gastrointestinal system, but targets and causes damage to the cerebellum of the brain. This portion of the brain is more closely related to motor skills, rather than cognition.

What is the difference between “celiac” and “gluten sensitivity”?

“Gluten” refers to the group of proteins making up 75-85% of the protein content in wheat and other cereal grains. When a person with celiac disease eats gluten-containing foods, the body recognizes these proteins as a threat to the body. In response it releases antibodies and attacks and damages the villi of the small intestine. In some severe cases the antibodies target and attack the central nervous system instead; sometimes specifically the cerebellum, causing ataxia symptoms. Autoimmune reactions to gluten are genetic and can be tested for with a blood sample. A gluten-free diet is the only known treatment for celiac sprue and gluten ataxia. 

Non-Celiac Gluten Sensitivity

Some people test negative for celiac, but still have a legitimate intolerance for digesting and processing gluten. This is called non-celiac gluten sensitivity (NCGS) or gluten sensitivity. NCGS typically does not cause as severe damage to the intestines as celiac, and is not related to autoimmune reactions that typically follow from celiac-induced intestinal permeability [1]. However, a chemical released in the gastrointestinal system in response to gluten called zonulin is a known cause for leaky gut (intestinal permeability) [2]. Although people with celiac disease tend to overproduce zonulin, just having too much gluten in the diet could logically trigger a similar effect. More zonulin means more toxins and gut contents pass into the bloodstream, causing reactions and symptoms throughout the body. 

Science has not yet determined the cause of NCGS, nor a test other than elimination of gluten from the diet. As research estimates that around 18 million Americans probably have gluten sensitivity (which is 6 times greater than the number of Americans with celiac), this is a fairly common food sensitivity [3]. Still many Western physicians are hesitant to diagnose patients with NCGS without a quantitative test. Often patients are diagnosed with IBS, but find a gluten-free diet alleviates some of their symptoms. Most NCGS diagnoses are self-diagnoses after experimenting with an elimination diet or made through an alternative practitioner. 

What neurological symptoms could be a response to gluten?

In a survey of patients with either celiac or non-celiac gluten sensitivity, over 90% of participants reported experiencing neurocognitive effects after eating gluten. The most common, specific neurocognitive symptom was “difficulty concentrating”, but other common symptoms included “forgetfulness”, “grogginess”, “detachment”, and “confusion” [2]. While some patients reported feeling the onset of these symptoms within an hour or two of consuming gluten, others felt them days later [2]. On average, patients reported the symptoms lasting for a couple of days [2]. Unfortunately, these effects may be irreversible and longer-lasting than those survey reports suggest. An Italian study reported that elderly celiac patients typically scored lower on cognitive tests than individuals without celiac, even after years on a gluten-free diet [4]. 

In comparison, symptoms of gluten ataxia are likely to be experienced as either sudden or gradual difficulties with motor skills [5]. You may notice feeling more clumsy, stumbling when walking, having difficulty buttoning your clothes, or slurring speech [5]. Brain fog is not a symptom of gluten ataxia.  

If you notice you are feeling more forgetful, groggy, or distracted than usual, go to your doctor while you are still eating gluten and ask to be thoroughly tested for celiac disease. If you take supplements, you may want to check the label to ensure they are gluten free,, like the ones produced by Metabolic Maintenance. It may take a while for your body to recover from its effects, so give it two to three weeks before you analyze the changes in your body and mind. What you ingest can have a huge effect on both the way you feel and think.


  1. Rubio-Tapia, Alberto, et al. “The prevalence of celiac disease in the United States.” American Journal of Gastroenterology 107.10 (2012): 1538-1544.
  2. Ehrenfeld, Temma. “Are you Brain Fogged from Bread?” Psychology Today. June 21, 2018.
  3. Beyond Celiac. “Non-celiac Gluten Sensitivity”. Beyond Celiac Website. Accessed July 6, 2020.
  4. Casella, Silvia, et al. “Cognitive performance is impaired in coeliac patients on gluten free diet: a case–control study in patients older than 65 years of age.” Digestive and Liver Disease 44.9 (2012): 729-735.

Anderson, Jane. “Gluten Ataxia Symptoms: What You Can Expect”. VeryWell Health. January 20, 2020.,fine%20control%20of%20voluntary%20movements.