The dietary burden of phosphorus and aluminum in ready-to-eat wheat flour tortillas exceeds that of corn tortillas: Implications for patients with chronic kidney disease.

Background: Ready-to-eat, shelf-stable tortillas contain several phosphorus- and aluminum-containing additives that may increase the risk of adverse events in patients with chronic kidney disease (CKD). Objective: The present study aimed to measure the dietary aluminum and phosphorus burden in store-bought corn and wheat flour tortillas. Design: This cross-sectional study analyzed the elemental content of commercially available corn and wheat flour tortillas collected from 2019 to 2020. Setting: Twenty-one elements were quantified by ICP-MS and ICP-OES from 14 corn and 13 wheat flour tortilla brands purchased from local supermarkets in Southern California in 2019-2020. Statistical analyses performed: Multiple group comparisons were analyzed by one-way ANOVA with Tukey's post hoc test. Outliers were identified using the ROUT test on GraphPad/PRISM and statistical significance was determined using nonparametric Mann-Whitney and Kruskal-Wallis tests. All conditions (soft corn, hard corn, and wheat) were compared using Dunn's multiple comparison test. Results: Ready-to-eat wheat flour tortillas generally contained more phosphorus than corn tortillas. Tortillas with aluminum listed as a food additive contained higher aluminum concentrations than those without such listing, exceeding the tolerable weekly intake. Conclusions: Our study suggests that food additives contribute to the dietary burden of aluminum and phosphorus in ready-to-eat wheat flour tortillas. While additional investigations are warranted to confirm our findings, food reformulation strategies and clear food labeling will aid in reducing excess phosphorus and aluminum intake from processed foods.