Are gluten-free diets more nutritious? An evaluation of self-selected and recommended gluten-free and gluten-containing dietary patterns

Authors: TAETZSCH, AMY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; DAS SAI, KRUPA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; BROWN, CARRIE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; KRAUSS, AMY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; SILVER, RACHEL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; ROBERTS, SUSAN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Nutrients
Publication Type: Review Article
Publication Acceptance Date: 11/23/2018
Publication Date: 12/3/2018
Citation: Taetzsch, A.G., Das Sai, K., Brown, C., Krauss, A., Silver, R.E., Roberts, S. 2018. Are gluten-free diets more nutritious? An evaluation of self-selected and recommended gluten-free and gluten-containing dietary patterns. Nutrients. 10(12). https://doi.org/10.3390/nu10121881.
DOI: https://doi.org/10.3390/nu10121881

Interpretive Summary: Gluten-free eating has become extremely popular in recent years, and the primary reason that individuals give for trying to follow a gluten-free diet is 'health'. We modeled the dietary composition of healthy diets with and without gluten-containing products and summarized existing dietary data on following a gluten free diet for medical reasons compared to people consuming a gluten containing diet. These studies found that, with the exception of sodium, gluten-free diets are not healthier than gluten-containing diets and instead there are several nutrients of public health significance that are lower in the gluten-free calculated intakes. Gluten-free dietary patterns should not be recommended except when medically indicated.

Technical Abstract: Gluten-free (GF) eating patterns are frequently perceived to be healthier than gluten-containing (GC) ones, but there is very little evidence to evaluate this viewpoint. The effect of GF eating patterns on dietary composition was evaluated using two independent approaches. One approach compared macronutrients and typical shortfall nutrients between MyPlate example menus developed with either GC or equivalent GF foods. In this analysis, the GF menus were significantly lower in protein, magnesium, potassium, vitamin E, folate, and sodium (P=0.002-P=0.03), with suggestive trends towards lower calcium and higher fat (P=0.06-0.08). The second approach was a meta-analysis of seven studies comparing information on the nutrient intakes of adults with celiac disease following a GF diet with control subjects eating a GC diet, and differences were evaluated using paired t-tests or Wilcoxon Signed rank tests. In this analysis, consuming a GF diet was associated with higher energy and fat intakes, and lower fiber and folate intakes compared to controls (P<0.001 to P=0.03). After adjusting for heterogeneity and accounting for the large mean effect size (-0.88+/-0.09), the lower fiber remained significant (P<0.001). These combined analyses indicate that GF diets are not nutritionally superior except for sodium, and in several respects are actually worse.