Anemia in non-celiac gluten sensitivity: a systematic review

Background

Non-celiac gluten sensitivity (NCGS) is characterized by a combination of intestinal and extra-intestinal symptoms triggered by gluten consumption, without evidence of celiac disease (CD) or wheat allergy (WA). Anemia, as an extra-intestinal manifestation, has been little studied in this context.

Main objective

To synthesize the available evidence on the association between NCGS and anemia.

Secondary objective

To evaluate studies applying the Salerno criteria as a diagnostic method.

Methods

Between November and December 2024, a search for scientific articles was conducted in the PubMed, Scopus, and Google Scholar databases, using the following terms: “anemia AND non-celiac gluten sensitivity”; “non-celiac gluten sensitivity AND clinical manifestations”; “non-celiac gluten sensitivity AND Salerno Experts.” Studies were included that either reported data on anemia in NCGS and/or used the Salerno criteria for the diagnosis of NCGS. The methodological quality of observational studies was assessed using the STROBE checklist, and the review was structured according to PRISMA 2020.

Results

18 studies were selected. The frequency of anemia in patients with NCGS ranged from 15% to 43%. Improvement in hemoglobin levels was reported after a gluten-free diet. Only 6 studies were developed according to the Salerno criteria.

Conclusions

NCGS should be considered in the differential diagnosis of anemia. The methodological quality of studies needs to be improved, ideally through double-blind controlled (DBPC) trials applying the Salerno criteria.