Improved Management of Chronic Kidney Disease with Plant-Dominant Low-Protein Diet
Chronic Kidney Disease (CKD) is noted to dominate >10% of patient diagnosis across the healthcare spectrum. “Each year, approximately 120,000 Americans develop end-stage kidney disease and initiate dialysis, which is costly and associated with functional impairments, worse health-related quality of life, and high early-mortality rates, exceeding 20% in the first year. Recent declarations by the World Kidney Day and the U.S. Government Executive Order seek to implement strategies that reduce the burden of kidney failure by slowing CKD progression and controlling uremia without dialysis”. Scientists continue to research and find benefits in management of CKD with low protein diets (0.6-0.8g/kg/day). More recently a greater benefit in slowing the progression of CKD has been found with a low protein diet composed of >50% plant-based protein sources.
Red and processed meat is associated with higher CKD risk, while nuts, low-fat dairy products, and legumes are protective against the development of CKD. Animal protein from beef, poultry, pork, lamb have a nitrogen based by-product that increases urea. Urea is one of the primary components of urine. With the progressive loss of kidney function, the kidneys will not properly excrete or regulate the levels of urea leading to high levels in the blood. Uremia untreated with dialysis or kidney transplant will cause multi-system and organ impairment. Evidence suggests that working with a Registered Dietitian (RD) to develop a plant-dominant low protein diet is “promising and consistent” with slowing the progression and controlling the side effects of CKD.
We have seen a rise in the use of high animal protein intake to combat obesity and diabetes despite recent data suggesting higher risk of CKD incidence and progression, especially from red meat. Keto-diets, which are high in protein and animal fats, are the latest trend in weight loss, thus also ultimately recommended in promoting control of diabetes. “Despite its immediate appeal for the use of type 2 diabetes, the ketogenic diet has not been as effective for glycemic control or weight loss in randomized, controlled trials as often touted and may carry additional risks to long-term health. Furthermore, previous and emerging data suggest that high protein diets, by way of causing increased intra-glomerular pressure with resultant glomerular hyperfiltration, may adversely affect kidney health over time across populations with or at-risk for CKD.”
Plant based foods increase fiber intake, whereas low fiber diets may increase the risk of constipation resulting in high potassium levels in the body. Potassium is found in many fruits and vegetables which are encouraged in a healthy low protein diet. However in the setting of CKD potassium is monitored, as impaired kidneys will no longer have the ability to properly or sufficiently remove excess potassium, thus levels will build up in the blood, a condition called hyperkalemia. Symptoms of high potassium: tired or weak, feeling of numbness or tingling, trouble breathing, chest pain, slow pulse, palpitations or irregular heartbeat. Significantly high potassium foods: banana, potato, tomato, avocado, orange, honeydew melon. It is suggested that a CKD patient work with a RD for a more complete list of high and low potassium foods and methods of leaching potassium from vegetables. Hyperkalemia and uremia become less of a concern for the CKD patient consuming adequate (25-35g) fiber and having regular bowel movements, slowing the progression of CKD, while also promoting cardiovascular health.
Phosphorus is a mineral found in our bones. Normal working kidneys can remove extra phosphorus in your blood. With CKD, phosphorus levels can build up and causing damage to the body. Extra phosphorus causes body changes that pull calcium out of your bones, making them weak. High phosphorus and calcium levels also lead to dangerous calcium deposits in blood vessels, lungs, eyes, heart. Over time this can lead to increased risk of heart attack, stroke or death. Whole grain wheat products contain high levels of phosphorus however with the use of phosphate binders and the benefit of the high fiber the whole grain products are recommended.
A plant-based diet may throw up a red flag for those trying to control obesity, metabolic syndrome or diabetes due to the carbohydrate load. However carbohydrates have different glycemic levels, conversely high protein diets or ketogenic diets are associated with adverse consequences in disease and health. Complex carbohydrates, including whole and minimally processed foods as well as fruits and vegetables can promote weight loss, improve cholesterol and triglyceride levels, decrease risk factors for diabetes, heart disease and weight related cancers.
As an additional benefit, plant-based foods are less expensive than animal based foods, including meat and poultry, in terms of cost per serving.
Plant based protein sources:
Nuts, nut butters
Beans-navy, kidney, black, great northern, garbanzo, etc
Soy proteins-tofu, tempeh, edemame
Split peas, black eyed peas
The patient and the dietitian should work together in establishing a patient-specific plant based meal plan. “Careful and balanced industry partnership can be sought to develop innovative help for people with CKD change their diet to delay the progression of the disease and to defer and prevent kidney failure”.
Resources: Nutrients 2020, 12, 1931; doi:10.3390/nu12071931 www.mdpi.com/journal/nutrients, Downloaded from nejm.org by KAMYAR KALANTAR-ZADEH on November 5, 2017.
Nicole Maslar RDN, LDN