Despite a controversial belief otherwise, new evidence suggests that diets high in protein do not adversely affect kidney function in healthy adults.
To examine this association, the researchers conducted a systematic review and meta-analysis of trials that compared higher-protein (HP) diets (≥1.5 g/kg body weight or ≥20% energy intake or ≥100 g protein/d) with normal- or lower-protein (NLP; ≥5% less energy intake from protein/d compared with HP group) diets on kidney function.
Overall, the review included 28 articles with data from 1358 participants. They used random-effects meta-analysis, meta-regression, and dose-response analysis, and conducted analyses of postintervention (post) glomerular filtration rate (GFR) and change in GFR from preintervention to post.
In the post-only comparison, the researchers observed a “trivial effect” for GFR to be higher after HP intake (standardized mean difference [SMD]: 0.19), and the change in GFR did not differ between interventions (SMD: 0.11).
In the post-only comparison, they also observed a linear relation between protein intake and GFR (r = 0.332), but not between protein intake and change in GFR (4 = 0.184).
“Postintervention GFR comparisons indicate that HP diets result in higher GFRs; however, when changes in GFR were compared, dietary protein had no effect. Our analysis indicates that HP intakes do not adversely influence kidney function on GFR in healthy adults.”
REFERENCE:
Devries MC, Sithamparapillai A, Brimble KS, et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis. The Journal of Nutrition. 2018. 148;11(1):1760–1775,