Dietary advice for patients with chronic kidney disease and renal failure is determined by a doctor's review of the patient's laboratory results. Kidney patients should never make dietary changes without consulting their nephrologist or their renal dietitian. If dietary changes are necessary, eating a restricted diet may minimize symptoms of advanced disease, such as nausea, and prevent serious consequences of kidney disease, such as heart attack and bone deterioration.
Protein
Some patients with advanced renal disease are advised to lower their protein intake because spilling protein into the urine damages the tiny filters in the kidneys called glomeruli. This advice changes once the patient reaches end-stage renal disease. For example, DaVita Dialysis explains that patients on dialysis should increase their protein intakes, because kidney dialysis removes amino acids from the blood. Likewise, patients who are post-transplant are instructed to eat extra protein to help them recover.
Potassium
The National Kidney Foundation explains that the kidneys keep serum potassium levels within a very narrow range. The kidneys of patients with advanced chronic disease are unable to perform this function, so the patient's serum potassium levels can easily get dangerously high and cause irregular heartbeats and even heart attacks.
When the kidneys can no longer control potassium levels, patients are advised to lower their potassium intake. Normally healthy foods, such as bananas, oranges, dried fruits, carrots, legumes, milk and milk products, must be eaten very sparingly because they contain too much potassium.
Phosphorus
Healthy kidneys prevent prevent serum phosphorus levels from getting too high. The National Institutes of Diabetes, Digestive and Kidney Diseases explains that regulating serum potassium is important, because high levels of serum potassium cause calcium to leach from the bones.
Patients who are approaching renal failure or are on dialysis can control their serum phosphorus levels by minimizing phosphorus intake. The National Kidney Foundation explains that beer, milk, milk products, oysters, legumes, nuts and bran cereals should be eaten very sparingly or avoided, because they have too much phosphorus for patients to consume safely.
Sodium
One of the many functions of the kidneys is to regulate blood pressure. The National Institutes of Diabetes, Digestive and Kidney Diseases explains that diseased kidneys are less able to perform this function, so patients become very sensitive to high sodium foods that raise the blood pressure. In addition to taking medication to control hypertension, the National Kidney Foundation explains that patients should limit table salt and soy sauce, and avoid other high sodium foods such as canned soups, most frozen meals, chips and salty snacks.
Fluid Intake
As patients approach renal failure, they may find themselves less able to urinate. Doctors often advise these patients to restrict their fluid intake to a particular limit. Foods such as ice cream, watermelon, jello and others with a high water content need to be factored into the patient's total daily fluid intake.
References
- DaVita: Some physical side effects of dialysis and how to prevent them
- National Kidney Foundation: Potassium and your CKD Diet
- National Kidney Foundation: Phosphorus and your CKD Diet
- National Institutes of Diabetes, Digestive and Kidney Diseases: Hypertension and Kidney Disease
- National Institutes of Diabetes, Digestive and Kidney Diseases: Chronic Kidney Disease-Mineral and Bone Disorder
