Commercially available gluten-free pastas elevate postprandial glycemia in comparison to conventional wheat pasta in healthy adults: A double-blind randomized crossover trial

Given the popularity of gluten-free diets, research regarding the health implications of gluten-free (GF) products is necessary. This study compared the postprandial glycemic responses to three GF pastas commonly available in the U.S. market to that of wheat pasta in healthy adults. Thirteen healthy non-smoking men and women from a university campus population were enrolled in this randomized 4 × 4 block crossover study and completed all four treatments. Participants followed a standardized diet and activity protocol the day prior to testing, and one week separated testing periods. The test meal (a macaroni and cheese dish prepared with conventional wheat pasta or with GF pasta composed of either brown rice, rice and corn, or corn and quinoa flours) was consumed under observation, and blood was sampled in the fasted state and at one-half hour intervals for the first 2 hours following meal ingestion. A significant pasta × time interaction was observed for the incremental postprandial glycemia curves (p = 0.036, repeated measures ANOVA; effect size [partial eta squared], 0.943). Post-hoc analysis revealed a significant difference for the 30-minute postprandial blood glucose concentrations: the plasma glucose concentration was 57% higher for the GF rice and corn pasta compared to traditional wheat pasta (p = 0.011). Since postprandial glycemia was higher for GF pasta composed of rice and corn flours compared to wheat pasta, more research is needed to understand how the substitute ingredients for GF pastas impact health parameters and disease risk.