Low‐protein diet for conservative management of chronic kidney disease: a systematic review and meta‐analysis of controlled trials

Abstract

BackgroundRecent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low‐protein diet can be a safe and effective means to avoid or defer transition to dialysis therapy without causing protein‐energy wasting or cachexia. We aimed to systematically review and meta‐analyse the controlled clinical trials with adequate participants in each trial, providing rigorous contemporary evidence of the impact of a low‐protein diet in the management of uraemia and its complications in patients with CKD.MethodsWe searched MEDLINE (PubMed) and other sources for controlled trials on CKD to compare clinical management of CKD patients under various levels of dietary protein intake or to compare restricted protein intake with other interventions. Studies with similar patients, interventions, and outcomes were included in the meta‐analyses.ResultsWe identified 16 controlled trials of low‐protein diet in CKD that met the stringent qualification criteria including having 30 or more participants. Compared with diets with protein intake of >0.8 g/kg/day, diets with restricted protein intake (<0.8 g/kg/day) were associated with higher serum bicarbonate levels, lower phosphorus levels, lower azotemia, lower rates of progression to end‐stage renal disease, and a trend towards lower rates of all‐cause death. In addition, very‐low‐protein diets (protein intake <0.4 g/kg/day) were associated with greater preservation of kidney function and reduction in the rate of progression to end‐stage renal disease. Safety and adherence to a low‐protein diet was not inferior to a normal protein diet, and there was no difference in the rate of malnutrition or protein‐energy wasting.ConclusionsIn this pooled analysis of moderate‐size controlled trials, a low‐protein diet appears to enhance the conservative management of non‐dialysis‐dependent CKD and may be considered as a potential option for CKD patients who wish to avoid or defer dialysis initiation and to slow down the progression of CKD, while the risk of protein‐energy wasting and cachexia remains minimal.

Does Kidney Longevity Mean Healthy Vegan Food and Less Meat or Is Any Low-Protein Diet Good Enough?

“…2 Low protein intake may have additional salutary effects, 3 including a reduction in the production of nitrogenous compounds that comprise uremic toxins; hence, a reduced dietary protein intake may be an ineffective strategy in controlling uremia and delaying the start of dialysis therapy, and it can also be used as a core component of the conservative management of CKD without dialysis. 4 The following ranges of dietary protein intake have been recommended for the management of CKD: (1) 0.6 to 0.8 g/kg ideal body weight (IBW) per day in patients with non-dialysis-dependent CKD stages 3b, 4, and 5 (estimated glomerular filtration rate , 45 mL/min/ 1.73 m 2 body surface area) or substantial albuminuria at A3 level (.300 mg/day); (2) 0.8-1 g/kg IBW per day in patients with CKD stages 1, 2, and 3a and without substantial albuminuria including patients with well-functioning transplants and persons with a solitary kidney or at a high risk of CKD such as those with diabetes mellitus or polycystic kidney disease. 1 It is important to note that in dialysis-dependent patients without residual kidney function, higher protein-intake targets are often recommended such as 1.2-1.4 g/kg IBW per day, and these patients should also eat during hemodialysis.…”

Healthy adult vegetarians have better renal function than matched omnivores: a cross sectional study in China.

“…We did not nd a relationship between protein intake and the eGFR. Previous studies have con rmed the effectiveness of low total protein intake in the prevention and treatment of renal dysfunction [15,32,33].…”

Green nephrology and eco-dialysis: a position statement by the Italian Society of Nephrology

“…In this regard, nutritional management is in keeping with the "R" of "Reduction" of the ecologic impact linked to dialysis need, with all the implications previously described [107,108]. Retarding dialysis has a comprehensive impact on other issues, such as transportation and use of hospital structures, usually lower in pre-dialysis patients than in those on dialysis [109][110][111].…”