Soy-based renoprotection

Abstract

Chronic kidney disease (CKD) is a significant public health problem as risk factors such as advanced age, obesity, hypertension and diabetes rise in the global population. Currently there are no effective pharmacologic treatments for this disease. The role of diet is important for slowing the progression of CKD and managing symptoms in later stages of renal insufficiency. While low protein diets are generally recommended, maintaining adequate levels of intake is critical for health. There is an increasing appreciation that the source of protein may also be important. Soybean protein has been the most extensively studied plant-based protein in subjects with kidney disease and has demonstrated renal protective properties in a number of clinical studies. Soy protein consumption has been shown to slow the decline in estimated glomerular filtration rate and significantly improve proteinuria in diabetic and non-diabetic patients with nephropathy. Soy's beneficial effects on renal function may also result from its impact on certain physiological risk factors for CKD such as dyslipidemia, hypertension and hyperglycemia. Soy intake is also associated with improvements in antioxidant status and systemic inflammation in early and late stage CKD patients. Studies conducted in animal models have helped to identify the underlying molecular mechanisms that may play a role in the positive effects of soy protein on renal parameters in polycystic kidney disease, metabolically-induced kidney dysfunction and age-associated progressive nephropathy. Despite the established relationship between soy and renoprotection, further studies are needed for a clear understanding of the role of the cellular and molecular target(s) of soy protein in maintaining renal function.

Nutritional Status Disorders in Chronic Kidney Disease: Practical Aspects (Systematic Review)

“…The results of studies on the model of unilateral ureteral obstruction in rats receiving LPD demonstrated a decrease in the expression of the nuclear factor of Kappa B transcription (NFkB), the most important mediator of activation of many proinflammatory and profibrotic cytokines and TGF-β-key as a profibrotic factor in the renal tissue [28,30]. LPD with an addition of soy protein to the diet reduces tubulointerstitial fibrosis also due to suppression of tyrosine protein kinase as a powerful sclerosis stimulant [30].…”

“…LPD with an addition of soy protein to the diet reduces tubulointerstitial fibrosis also due to suppression of tyrosine protein kinase as a powerful sclerosis stimulant [30]. Currently, the possibility of LPD influence to maintain the serum level of klotho protein, as an established strong early cardio and nephroprotective factor, is being actively studied [29].…”

“…The antihypertensive effect of soy protein is due to the isoflavone in it, genistein (an estrogen of plant origin) that has an anti-inflammatory effect and a protective effect on the vascular endothelium (8 mg of isoflavone is contained in 1 g of soy protein). Soy protein contains more than animal protein, arginine (7.6% vs. 3.7%)-the precursor of NO and glycine (4.2% vs. 1.8%), which inhibit the stress hormone adrenalin and contribute to vasodilation [19,30].…”

“…Soy protein is less able than animal protein (meat, fish, milk, etc.) to increase hyperperfusion and hyperfiltration in remnant nephrons [30].…”

“…Plant protein has a lower biological value, since it does not contain the whole composition of EAA. The exception is the soy protein, which is close to the protein of animal origin in the spectrum of EAA [1,18,19,30].…”