Chronic kidney disease: causes and importance of nutrition
Did you know that a plant-based diet can be very important in cases of chronic kidney disease?
Chronic kidney disease (CKD) encompasses a range of conditions that damage the kidneys and reduce their ability to keep the body healthy. Among the main functions of the kidneys, the elimination of waste, the control of body fluids and blood pressure, the regulation of the hydro-electrolyte and acid-base balance, the synthesis and regulation of hormones are highlighted. Furthermore, the kidney is one of the main organs involved in the metabolism of nutrients and nutritional balance in the body.
CKD is characterized by progressive deterioration of renal function. As the kidneys lose their ability to filter, electrolytes and toxic substances build up in the blood.
Chronic kidney disease has implications for the individual's health and well-being, with consequences such as anemia, bone diseases, sleep disorders, gastrointestinal disorders, etc.
Kidney disease affects millions of people around the world, and it is estimated that it affects 10% of the world population, covering all age groups, although its incidence is higher in adults and elderly people.1
The most severe stage occurs when renal function below 15% of normal is reached and when it becomes necessary to resort to a renal function replacement technique, such as dialysis (hemodialysis or peritoneal dialysis) or transplantation.
If kidney disease is detected early, medication and changes in diet and lifestyle can prolong the “life” of the kidneys and allow the person to continue feeling well for longer.
Prevention, early detection, and treatment are especially important for kidney disease because chronic kidney damage is often permanent, requiring the use of dialysis or transplantation once it has completely failed.
The cause
Diabetes and high blood pressure are conditions responsible for two-thirds of chronic kidney disease. On the other hand, people with a family history of kidney disease are more likely to suffer from this disease. Also, some kidney diseases can become chronic.
Urinary tract diseases such as glomerulonephritis, pyelonephritis, polycystic kidneys, diseases that affect the immune system such as lupus or severe recurrent urinary infections are some examples.
The importance of food
A diet that favors whole foods based on vegetables has proven to be highly effective in the prevention and treatment of type 2 diabetes, high blood pressure, and cardiovascular diseases. It means that it affects most of the causal factors of this pathology as well as the main cause of death in patients with kidney disease. 2
Many other authors advise and point out the beneficial aspects of protein restriction when kidney damage already exists, namely, in delaying the progression of kidney disease, delaying or preventing the need for dialysis or transplantation. 3-6
Vegetarian diets have been promoted as a way to delay the progression of kidney disease, managing to maintain an adequate nutritional status of patients, as long as they are calculated taking into account the limiting amino acids.7
In fact, there is evidence to suggest that substituting just one serving of red meat for soy and vegetables a day could reduce the risk of end-stage kidney disease (stage 5) by 50%. 8
In kidney disease, dietary phosphate restriction is often necessary. Today, food includes numerous processed foods and beverages in which additives and preservatives with a high content of inorganic phosphorus are used. Often, these “hidden” sources are not accounted for, as they are usually not described either on the labeling or in the food composition tables. A simple and effective way to reduce the amount of dietary phosphorus, without significantly reducing the amount of protein, is to avoid the consumption of soft drinks with phosphorus in their constitution, pre-cooked meals, and other processed foods with phosphorus additives.9
If you wish to transition to whole food plant-based eating, it is essential to discuss this objective with your physician first and proceed under medical supervision. Each patient has their own individuality and deserves to maintain it, having their own food plan, according to their clinical situation and individual needs.
Bibliographic references:
Carney, E.F. The impact of chronic kidney disease on global health. Nat Rev Nephrol 16, 251 (2020).
Chauveau P, Koppe L, Combe C et al. Vegetarian diets and chronic kidney disease. Nephrol Dial Transplant 2018; 1-9
Martin WF, Armstrong LE, Rodriguez NR. Dietary protein intake and renal function. Nutrition & metabolism. 2005;2:25
Fouque D, Laville M. Low protein diets for chronic kidney disease in nondiabetic adults. The Cochrane database of systematic reviews. 2009(3): CD001892
Nezu U, Kamiyama H, Kondo Y et al. Effect of low-protein diet on kidney function in diabetic nephropathy: a meta-analysis of randomized controlled trials. BMJ Open. 2013 May 28;3(5).
Hahn D, Hodson EM, Fouque D. Low protein diets for non-diabetic adults with chronic kidney disease. Cochrane Database Syst Rev Oct 2018; 10:CD001892
Bernstein AM, Treyzon L, Li Z. Are high-protein, vegetable-based diets safe for kidney function? A review of the literature. J Am Diet Assoc. 2007;107(4):644-50
Lew QJ, Jafar TH, Koh HW et al. Red Meat Intake and Risk of ESRD. J Am Soc Nephrol. 2017 Jan;28(1):304-312
D’Alessandro C, Piccoli GB, Cupisti A. The “phosphorus pyramid”: a visual tool for dietary phosphate management in dialysis and CKD patients. BMC nephrology. 2015