Most newly diagnosed patients want to know if they can control their kidney disease by diet. There are no one-size-fits-all answers here because dietary advice is given in response to individual lab results. Realistically, diet is more involved in treating the symptoms of renal failure rather than slowing down the progression of the disease. While you may not be able to prevent renal failure, you can control many of the more harmful aspects of it -- and be a healthier candidate for transplant and dialysis.
Phosphorus
Many patients with advanced kidney disease are at risk for weakened bones if their phosphorus levels are too high. Phosphorus helps regulate the amount of calcium in bone. When serum levels of phosphorus get too high, the phosphorus starts pulling calcium from the bone.
Healthy kidneys routinely remove excess phosphorus from the blood. However, if renal function is impaired, kidneys are less able to perform this important function. Dietary restriction of phosphorus -- along with taking drugs that deactivate the phosphorus -- is the best way to prevent bone damage.
Potassium
Keeping the concentration of potassium within a narrow range is essential to healthy functioning of the nervous system. If nerves fire erratically, the heart does not beat steadily. Irregular heartbeats and heart attacks can result. As kidneys becomes progressively compromised by disease, they are less able to remove excess potassium. If potassium levels are higher than 5.0 mg/dL, your nephrologist might advise potassium restriction to protect the nervous system and prevent heart problems.
Protein Before Transplant
Medical advice about eating protein may seem contradictory. In the early stages of kidney disease, nephrologists sometimes counsel protein restriction, particularly if the patient is not a child and urine protein levels are high. The rationale here is that by controlling high urine protein, damage to the kidney can be minimized. This advice changes as the patient approaches end stage disease. Patients approaching transplant are encouraged to eat as much protein as possible because this will help them heal after surgery. Patients on dialysis are given the same advice because dialysis removes certain amino acids from the blood.
Sodium
Since the kidneys are involved in regulating blood pressure, hypertension and renal disease commonly occur together. This is unfortunate because the tiny filters in the kidney, called glomeruli, are little more than nests of tiny capillaries. Hypertension destroys these fragile structures which is why nephrologists often advise patients to consume less sodium. Lowering blood pressure through a low-sodium diet and blood pressure medication helps extend the life of the kidneys by preserving these delicate structures.
References
- National Institute of Diabetes and Digestive and Kidney Disease; Chronic Kidney Disease -- Mineral and Bone Disorder; February 2009
- National Institute of Diabetes and Digestive and Kidney Diseases; Treatment Methods for Kidney Failure: Hemodialysis; December 2006
- DaVita; Dietary Protein and Chronic Kidney Disease (CKD); July 2005
- National Institute of Diabetes, Digestive and Kidney Diseases; High Blood Pressure and Kidney Disease; July 2008
