Food Additives: Emerging Implications for Kidney Health

Ultra-processed foods (UPFs) represent one of the major sources of industrial food additives (IFAs). The increasing consumption of UPFs has determined an enhancement of dietary exposure to IFAs, including phosphorus, sodium and potassium-based compounds, and to emulsifiers, preservatives and synthetic colorants. Although these additives improve food stability and extend shelf life, increasing evidence suggests that they may adversely affect kidney health by promoting oxidative stress (OS), systemic chronic inflammation, gut dysbiosis, endothelial dysfunction and disturbances in mineral metabolism, mainly in chronic kidney disease (CKD) patients. This review aims to analyze the current evidence on the impact of IFAs on kidney health in the general population and on the progression of CKD in nephropathic patients. It discusses the potential of natural bioactive compounds (NBCs) as safer alternatives capable of combining food preservation with kidney protection. The literature data show that high UPF consumption is associated with an increased risk of CKD onset and progression. In contrast, NBCs, which substitute the use of IFAs, exhibit antioxidant, anti-inflammatory, antimicrobial and nephroprotective properties. They also show promising technological applications as natural preservatives, emulsifiers and colorants, supporting their use as alternatives to IFAs. In conclusion, IFAs might contribute to CKD onset and progression, whereas NBCs represent promising alternatives capable of combining technological functionality with potential benefits, above all, on renal health. However, well-designed clinical trials are required to confirm the long-term efficacy and safety of NBCs in CKD prevention and management.