Non-Pharmacological Activation of the Renal Kallikrein–Kinin System: Dietary Potassium as a Novel Renoprotective Approach

Chronic kidney disease (CKD) has emerged as a pervasive global health concern, for which there are no known curative treatments. Consequently, there is an imperative for the implementation of preventive and kidney-protective strategies. The renal kallikrein–kinin system (KKS) is a vasodilator, anti-inflammatory, and antifibrotic pathway located in the distal nephron, whose decline contributes to hypertension and CKD progression. In this narrative, non-systematic review, a thorough evaluation of both experimental and clinical data was undertaken to ascertain the interactions between dietary potassium, renal KKS activity, and kidney protection. A particular emphasis was placed on animal models of proteinuria, tubulointerstitial damage, and salt-sensitive hypertension, in conjunction with human studies on potassium intake and renal outcomes. A body of experimental evidence suggests a relationship between potassium-rich diets and renal kallikrein synthesis, urinary kallikrein activity, and up-regulated kinin B2 receptor expression. Collectively, these factors have been shown to result in reduced blood pressure, oxidative stress, apoptosis, inflammation, and fibrosis, and these effects are counteracted by B2 receptor blockade. In humans, higher potassium intake has been shown to enhance kallikrein excretion and lower cardiovascular and renal risk, independently of aldosterone. Conversely, low potassium intake has the potential to exacerbate CKD progression. Notwithstanding the concerns that have been raised regarding the potential necessity of increasing potassium intake in cases of advanced CKD, extant evidence would appear to indicate that potassium excretion persists until late disease stages. The activation and preservation of the renal KKS through a potassium-rich diet is a rational, cost-effective strategy for renoprotection. When combined with sodium reduction and nutritional education, this approach has the potential to halt the progression of CKD and enhance cardiovascular health on a population scale.