Dietary Patterns and Kidney Health: An Umbrella Review of Systematic Reviews and Meta-Analyses

CONTEXT: Chronic kidney disease (CKD) is a major clinical kidney disease associated with numerous adverse events, such as heart failure and premature mortality. Dietary modifications are prioritized in the management of CKD due to the long-term effects of this disease. OBJECTIVE: In this review we sought to consolidate evidence from published systematic reviews and meta-analyses performed to investigate the associations between different dietary patterns and kidney health. DATA SOURCES: We searched related systematic reviews and meta-analyses in PubMed, Embase, Ovid, and the Cochrane Database of Systematic Reviews. DATA EXTRACTION: Two independent reviewers undertook screening, data extraction, and quality assessment. The corrected covered area was used to identify the degree of overlap between reviews. Exposures included the amount of protein/salt intake, types of dietary protein, ketoanalogue (KA) supplementation, the Mediterranean diet, and the Dietary Approaches to Stop Hypertension (DASH) diet. DATA ANALYSIS: In total, 28 reviews evaluating the associations between multiple dietary patterns and kidney health were included. According to reported review findings, a low-protein diet (LPD) reduced proteinuria in CKD patients. A very low-protein diet (VLPD) was shown to decrease the occurrence of end-stage renal disease. Supplementation with KA based on the LPD/VLPD further reduced levels of proteinuria, blood urea nitrogen, and serum creatinine and preserved the estimated glomerular filtration rate (eGFR) in CKD patients. Lower sodium intake effectively decreased urinary sodium and protein excretion and produced a significant reduction in the incidence of composite endpoints in CKD patients. Both the Mediterranean and the DASH diet mitigated the risk of CKD, while the latter also showed benefits in reducing proteinuria and rate of eGFR decline. CONCLUSIONS: Although the aforementioned dietary interventions did not directly improve patient mortality, they showed protective effects in lowering proteinuria, preserving renal function in CKD patients and reducing the risk of CKD in the non-CKD population. Clinicians should acknowledge the impact of various dietary patterns on kidney health to achieve better prevention and management of kidney diseases. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration No. [CRD42022313262].