Addition of Gluten to a Food and Nutrient Database. Bhaskarani Jasthi, PhD RD, Janet Pettit, and Lisa Harnack, DrPH RD. University of Minnesota Nutrition Coordinating Center.

Background: Gluten is a protein found in wheat, rye, barley and their crossbred varieties and derivatives. It is responsible for triggering hypersensitivity reactions in people with celiac disease, and research is underway to determine whether it may contribute to other health outcomes.

Objective: Add gluten to the Nutrition Coordinating Center (NCC) Food and Nutrient Database so that researchers conducting studies related to gluten may assess intake of this food component.

Description: Few foods have been chemically analyzed for their gluten content. Consequently, gluten values were assigned to foods in the NCC Food and Nutrient Database using imputation procedures based on two assumptions. The first is that foods that do not include any wheat, rye or barley grain ingredients or their derivatives are presumed to contain 0 grams of gluten. Thus, foods such as fruits, vegetables, and vegetable oils were assigned gluten values of 0 grams.

The second is that a specified fraction of protein found in wheat, rye, barley and their crossbred varieties and derivatives (0.75) is presumed to be gluten. The factor of 0.75 was selected based on findings from studies in which chemical analysis of some gluten containing grains and their derivatives were carried out to estimate the percentage of gluten. It is important to note that gluten values in the NCC Database may not be appropriate for use in determining whether a food or diet is gluten-free because foods with “zero” values may not meet the FDA definition of gluten-free (<20 parts per million of gluten). However, the values may be useful in determining whether a food or diet is low, moderate or high in gluten.

Conclusion: The approach used to add gluten to the NCC Database may be a useful model for other database developers, though the approach has some limitations.