Gluten-induced Neurocognitive Impairment: Results of a Nationwide Study.

Goals: This study aimed to understand the neurocognitive symptoms associated with gluten exposure in individuals with self-reported celiac disease (CD) and nonceliac gluten sensitivity (NCGS).

Background: While gluten-induced neurocognitive impairment (GINI; eg, "celiac fog" or "brain fog") is commonly described by individuals with CD and NCGS, there are little data regarding the prevalence and symptoms associated with these experiences.

Study: A 9-question online survey was accessed by 1396 individuals (1143 with CD; 253 with NCGS). Forced choice and free-response questions were asked of participants to obtain a description of neurocognitive symptoms experienced after gluten ingestion. Free-response answers were coded using a coding structure developed based on the Health-Related Quality of Life Instrument.

Results: The majority of survey participants (89% of CD and 95% of NCGS) reported having GINI symptoms. When describing symptoms, the most common word descriptors for both groups were difficulty concentrating, forgetfulness, and grogginess. Timing of symptoms, including onset and symptom peak, were similar across the 2 groups. Coding of free responses found the most common references were to cognitive, physical, psychological, and overall quality of life impacts.

Conclusions: This survey suggests that GINI is common and may be severe in both individuals with CD and NCGS. Cognitive impairment and decline in physical functioning may be similar to that occurring in other illnesses, such as lupus. Clinical follow-up with both individuals with CD and NCGS should include assessment of GINI symptoms. Further research is warranted, including the development of a patient-reported outcome measure including neurocognitive effects of gluten exposure.