Ultra-Processed Food and Chronic Kidney Disease Risk: A Systematic Review, Meta-Analysis, and Recommendations

Background: Ultra-processed foods (UPFs) are formulations of ingredients that are mostly of exclusive industrial use and may contain additives like artificial colors, flavors, or stabilizers. The sale and consumption of these foods have been increasing despite their associations with increased risk for several non-communicable diseases, including chronic kidney disease (CKD). Compared to less processed and perishable foods, UPFs have longer shelf stability, are widely accessible, and are convenient. They also tend to be more affordable and lower in nutritional quality. The aim of this systematic review and meta-analysis (PROSPERO ID: CRD42023488201) was to investigate whether consumption of UPF is associated with a higher risk of CKD in adults. Methods: We completed a systematic search using Medline, EMBASE, CINAHL, and Cochrane Central databases to identify observational studies published since the wide acceptance of UPF classification and conducted a random-effects model to pool the risk estimates. Results: A total of seven studies met the inclusion criteria for the systematic review, of which four were eligible for meta-analysis. Across these studies, there were 19,645 incident CKD cases from individuals free of baseline CKD. Using a random-effects model, higher UPF intake was significantly associated with increased CKD risk (pooled log-hazard ratio = 0.17; 95% CI: 0.07-0.28; p < 0.001). Conclusions: Given the substantial evidence from this systematic review and meta-analysis indicating an association between UPF and CKD, it is recommended for public health policies to address this risk. Promoting dietary guidelines that encourage the consumption of minimally processed foods could potentially mitigate the prevalence of CKD and improve overall public health outcomes.