Cysts on the kidneys are a symptom of polycystic kidney disease. PKD is a progressive disease that can result in kidney failure. While there are no peer-reviewed, evidence-based studies that show diet as any effect on the formation or prevention of these cysts, what you eat is important in controlling the symptoms of the advanced kidney disease.
PKD
There are two forms of PKD. Approximately 90 percent of all PKD patients have autosomal dominant PKD. This means that their disease is caused by a dominant gene. The remaining 10 percent of PKD patients have autosomal recessive PKD, which is caused by a recessive gene. According the National Kidney and Urologic Diseases Information Clearinghouse, approximately 50 percent of people with autosomal dominant PKD will eventually go into kidney failure. For these people, diet is very important as renal failure approaches.
Potassium
Nephrologists routinely measure potassium levels in kidney patients' blood because potassium levels can become elevated as kidney disease approaches. Elevated potassium levels, also known as hyperkalemia, cause nerves to misfire, which in turn, causes irregular heartbeats. Nephrologists recommend a low-potassium diet for patients with hyperkalemia. While your nephrologist can tell you how much potassium is safe for you to eat, most nephrologists suggest that patients consume less than 2,000 to 3,000 mg of potassium.
Protein
Like other kidney patients, people with PKD often have high urine protein, or proteinuria. This proteinuria is undesirable because the glomeruli, or kidney filters, are delicate structures that are little more than very fine capillaries. They weren't designed to have large molecules like proteins passing through their membranes. If patients with PKD have high urine protein, that factor alone will accelerate the progression of kidney disease. For this reason, nephrologists often recommend a low-protein diet, particularly in the latter stages of disease. If you have PKD, ask your nephrologist how much protein you should eat.
Phosphorus
As renal failure approaches, serum levels of phosphorus can also become elevated. This is dangerous because high levels of phosphorus start pulling calcium from the bone. Nephrologists try to prevent this from happening by recommended a low-phosphorus diet and prescribing phosphorus binders that cause dietary phosphorus to be excreted. High phosphorus foods include cocoa, beer, milk products, organ meats and legumes.
References
- PKD Foundation: Just Diagnosed
- National Kidney & Urologic Diseases Information Clearinghouse; Polycystic Kidney Disease; November 2007
- National Kidney Foundation: KDOQI Clinical Practice Guideline for Nutrition in Children with CKD: 2008 Update
- National Kidney Foundation: Potassium and our CKD Diet
- National Kidney Foundation: Phosphorus and Your CKD Diet
- National Kidney & Urologic Diseases Information Clearinghouse; Proteinuria; September 2010
