The gluten-free diet is based on the idea that gluten—a protein found in wheat, barley, and rye—may be toxic in certain individuals and cause intestinal and extra-intestinal symptoms, including "brain fog." Although a gluten-free diet may promote brain health in rare individuals with celiac disease or gluten sensitivity, there is no evidence that it does so in other individuals.
Celiac disease (CD) is a genetic, autoimmune disorder that affects ~1 percent of the population and may develop at any age, even in people who previously tested negative. When patients with CD consume gluten, they can experience a range of symptoms, including abdominal pain, cramping, nutrient malabsorption, and neurological problems. Some people with CD also report brain fog, or cognitive impairment, which may improve when the patient stops eating gluten. While studies show CD patients on a gluten-free diet reap health benefits, very few studies have evaluated whether their cognition improves.
Non-celiac gluten sensitivity (NCGS) is a distinct and less understood condition that is neither an allergic nor autoimmune disorder. NCGS patients report many of the same symptoms as those with CD, including brain fog, but no studies have yet reported whether cognition improves in patients with NCGS when they adhere to a gluten-free diet.
Anecdotal reports suggest that following a gluten-free diet may reduce inflammation, which could in theory reduce neuroinflammation and promote brain health. However, we could find no evidence for this, particularly for non-celiac patients. There is also a rationale that reducing the intake of processed carbohydrates and sugars may reduce risk for metabolic disease and Alzheimer’s disease, but no studies suggest that specifically reducing intake of gluten confers more benefit than reducing processed carbohydrates in general. In other words, gluten itself does not appear to be the culprit.
Although the gluten-free diet is growing in popularity and has been touted for its cognitive benefits, there is no evidence that the diet is beneficial for cognitive health, except possibly for the small percentage of the population with celiac disease. For healthy people, eliminating whole grains from your diet may reduce your intake of important vitamins, minerals, and fiber. More studies are needed to test the effect of going gluten-free on brain health and risk of cognitive decline and dementia.
We have examined the existing evidence on a number of different diets for their potential to benefit brain health. Currently, the three with the most evidence of benefit are the Mediterranean, DASH, and MIND diets.
Nick McKeehan is a member of the ADDF's Aging and Alzheimer's Prevention program. He evaluates the scientific evidence for and against therapies to promote brain health and/or prevent Alzheimer's disease at our website CognitiveVitality.org and contributes regularly to the site's blog. Mr. McKeehan previously served as Chief Intern at Mid Atlantic Bio Angels (MABA) and was a research technician at Albert Einstein College of Medicine investigating repair capabilities of the brain. Mr. McKeehan received a bachelor of science degree in biology from Purdue University, where he was awarded a Howard Hughes Scholarship. He also writes about the biotechnology industry for 1st Pitch Life Science.
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