The Effects of High-Protein Diets on Kidney Health and Longevity

Abstract

Although high-protein diets continue to be popular for weight loss and type 2 diabetes, evidence suggests that worsening renal function may occur in individuals with-and perhaps without-impaired kidney function. High dietary protein intake can cause intraglomerular hypertension, which may result in kidney hyperfiltration, glomerular injury, and proteinuria. It is possible that long-term high protein intake may lead to de novo CKD. The quality of dietary protein may also play a role in kidney health. Compared with protein from plant sources, animal protein has been associated with an increased risk of ESKD in several observational studies, including the Singapore Chinese Health Study. Potential mediators of kidney damage from animal protein include dietary acid load, phosphate content, gut microbiome dysbiosis, and resultant inflammation. In light of such findings, adopting current dietary approaches that include a high proportion of protein for weight reduction or glycemic control should be considered with care in those at high risk for kidney disease. Given the possibility of residual confounding within some observational studies and the conflicting evidence from previous trials, long-term studies including those with large sample sizes are warranted to better ascertain the effects of high protein intake on kidney health.

Keywords: chronic kidney disease; glomerular hyperfiltration; high protein diet; nutrition; proteinuria.

Figure 1.

High dietary protein intake leads to the dilation of the afferent arteriole and increased GFR, which may lead to damage to kidney structures over time due to glomerular hyperfiltration.

Figure 2.

High dietary protein may lead to dilation of afferent arterioles, which results in intraglomerular pressure and glomerular hyperfiltration. It could damage glomerular structure causing compensatory increase of glomerular pressure in remaining glomerulus over time.