Abstract and Introduction
Abstract
While dietary restriction of protein intake has long been proposed as a possible kidney-protective treatment, the effects of changes in the quality of ingested proteins on the prevalence and risk of progression of chronic kidney disease (CKD) have been scarcely studied; these two aspects are reviewed in the present article. The prevalence of hypertension, type 2 diabetes and metabolic syndrome, which are the main causes of CKD in Western countries, is lower in vegetarian populations. Moreover, there is a negative relationship between several components of plant-based diets and numerous factors related to CKD progression such as uraemic toxins, inflammation, oxidative stress, metabolic acidosis, phosphate load and insulin resistance. In fact, results from different studies seem to confirm a kidney-protective effect of plant-based diets in the primary prevention of CKD and the secondary prevention of CKD progression. Various studies have determined the nutritional safety of plant-based diets in CKD patients, despite the combination of a more or less severe dietary protein restriction. As observed in the healthy population, this dietary pattern is associated with a reduced risk of all-cause mortality in CKD patients. We propose that plant-based diets should be included as part of the clinical recommendations for both the prevention and management of CKD.
Introduction
For more than a century, the quantitative reduction of dietary protein intake has been recognized as a therapeutic measure in chronic kidney disease (CKD). In contrast, the relationship between dietary protein sources and the risk of incident CKD and its progression has long been neglected. The purpose of the present article is to successively provide information on these two topics through recent data from the medical literature.
First, to date, there seems to be a lack of reports on the prevalence of renal disease in the vegetarian population, whereas numerous studies have shown a decrease in the risk of hypertension,[1] type 2 diabetes[2] and metabolic syndrome (MetS),[3,4] which are the main causes of CKD in Western countries, in vegetarian populations. Given these findings, it would seem reasonable to assume that the renal consequences of these diseases should also be less prevalent among vegetarians.
Second, numerous studies have shown that plant-based diets are associated with a decrease in many risk factors associated with CKD progression, such as hypertension,[5] uraemic toxins,[6] inflammation[7] and oxidative stress,[8] preventing the development of some metabolic disorders.[9] Thus one could be led to speculate on the potential benefits of plant-based diets on renal outcomes in CKD patients. As a matter of fact, these benefits have already been confirmed in most studies.[10,11]
As Mariotti did in his book,[12] in this review we used the term 'vegetarian' to include all forms of vegetarian diet, from lacto-ovo-vegetarian to strict vegan. In cases where a study referred to a particular diet, we mention the diet in question.
Nephrol Dial Transplant. 2019;34(2):199-207. © 2019 Oxford University Press
