Dietary burden of phosphorus and aluminum concentrations of ready-to-eat wheat flour tortillas exceed that of corn tortillas: Implications for patients with renal or cardiovascular disease

Background Ready-to-eat, shelf-stable tortillas contain several phosphorus- and aluminum-containing additives that may increase risk of adverse events in patients with chronic kidney disease (CKD). Aim The present study analyzes and compares the elemental content of wheat flour and corn tortillas with special reference to dietary aluminum and phosphorus burden. Methods Twenty-one elements were quantified by ICP-MS and ICP-OES in 14 corn and 13 wheat flour tortilla brands purchased from local supermarkets in Southern California. Results The aluminum and phosphorous concentrations of many ready-to-eat tortilla brands can present a daily dietary load of up to approximately 100 mg aluminum and 700 mg phosphorus based on an average daily intake of 330 grams. Ready-to-eat wheat flour tortillas generally had more phosphorus than corn tortillas. Tortillas with aluminum listed as a food additive contained a higher aluminum content than those without such listing, exceeding the tolerable weekly dietary intake. Conclusions Despite conventional wisdom that CKD patients should avoid phosphorus-rich corn tortillas, ready-to-eat wheat flour tortillas consistently had a higher aluminum and phosphorus content due to additives. CKD patients and health care providers should pay attention to food labels, and regulatory authorities should monitor the use of approved food additives and mandate food label warnings for patients at risk. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study did not receive any funding. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors. * P : Phosphorus Al : aluminum CKD : chronic kidney disease TWI : tolerable weekly intake ICP-MS : inductively coupled plasma mass spectrometry ICP-OES : inductively coupled plasma optical emission spectroscopy