Abstract Context Dietary protein requirements for older adults with normal kidney function or nondialysis chronic kidney disease (CKD) are still not clearly understood. Low protein intake is often recommended for the management of CKD, although some evidence suggests that higher protein intake may reduce the risk of protein energy malnutrition and sarcopenia among older adults. Objective To systematically review and synthesize the longitudinal evidence on the association between dietary protein intake and kidney function in community-dwelling older adults (≥65 years) with normal kidney function or nondialysis CKD. Data Sources Embase, Medline, and Scopus electronic databases, along with the Web of Science platform, were systematically searched from inception to November 7, 2025. Data Extraction The search yielded 2325 articles. Title and abstract, as well as full-text review, were independently performed by 2 reviewers. A total of 6 studies met our inclusion criteria. Data extraction was completed by 1 reviewer and independently cross-checked by another. The ROBINS-E tool was used to assess the risk of bias and the GRADE approach was used to assess the certainty of evidence. Data Analysis and Results Due to limitations in available evidence, a meta-analysis could not be performed, and a narrative review approach was adopted instead. Five of the 6 included studies reported no statistically significant association between protein intake and kidney function in older adults with normal kidney function or nondialysis CKD, while, in 1 study, higher plant protein intake was associated with slower estimated glomerular filtration rate (eGFR) decline. Conclusion There was insufficient evidence that dietary protein intake impacted longitudinal kidney function in community-dwelling older adults not on dialysis; however, research in this area is lacking. Further research may inform the development of more personalized interventions to optimize protein intake and health in later life. Systematic Review Registration PROSPERO registration no. CRD42024567168.
Qannas et al. (Fri,) studied this question.