When the kidneys filter the blood, they excrete excess minerals in the urine. The urine travels to the bladder and stays there until urination occurs. As a result, any foods and beverages you consume have an effect on your urinary system. Diet affects the status of kidney disease and renal failure, plays a role in episodes of interstitial cystitis, affects bladder cancer risk and contributes to the formation of kidney stones.
Kidney Dysfunction
Anyone with kidney dysfunction should follow a renal diet, which requires restriction of sodium, potassium and phosphorus intake. Eating foods low in these nutrients prevents them from building up in the bloodstream when the kidneys cannot filter them effectively. People with kidney disease and kidney failure also need to limit the amount of protein they consume, as the protein is a precursor to a waste product called creatinine. Since the kidneys cannot filter creatinine as well as they should, eating less protein reduces the amount of creatinine that accumulates in the bloodstream.
Interstitial Cystitis
Interstitial cystitis refers to chronic inflammation of the bladder wall. This condition causes pelvic pain, urinary frequency, pain during intercourse and urinary urgency. The Interstitial Cystitis Association recommends diet modification for those who have this painful condition. Although no specific diet exists for people with interstitial cystitis, eliminating trigger foods seems to help prevent flares. Coffee, spicy foods, citrus juices, alcohol, hot peppers, soft drinks, cranberry juice and artificial sweeteners cause the most problems for IC patients, but other foods can also trigger flares. Using a food diary and elimination diet helps identify these trigger foods. ICA also recommends eating specific foods during flares to combat pain. This list of foods includes green beans, chicken, rice and bread.
Bladder Cancer Risk
What you eat also affects your risk of bladder cancer. The National Cancer Institute reports that a diet high in fatty foods and fried meats increases the risk for this disease. Some foods can also reduce your risk when eaten regularly. In a study conducted by Steven Schwartz and his colleagues at Ohio State University, researchers determined that men who ate two or more servings of broccoli per week had a 44 percent lower incidence of this type of cancer when compared with men who ate less than one serving of broccoli per week.
Kidney Stones
Kidney stones form when minerals build up in the urinary tract. The most common type of stone is made of calcium and other substances such as oxalate. Uric acid stones form when too much uric acid builds up in the urine. Diet affects your risk of developing both types of stones. Prevention of calcium oxalate stones requires a diet low in oxalates. This diet restricts the consumption of foods with more than 10 mg of oxalate per serving. You should avoid chocolate, pretzels, cereal, nuts, sesame seeds, citrus peel, potatoes, peppers, spinach, zucchini, fruit cocktail and elderberries. When you consume meat, your body breaks it down into uric acid and other substances. If you have a high risk of developing uric acid kidney stones, your doctor may recommend reducing the amount of meat you eat each day.
References
- Medical College of Wisconsin: Diet for Renal Patient
- Interstitial Cystitis Association: IC Elimination-Challenge Diet
- National Cancer Institute: General Information About Bladder Cancer
- Ohio State Research; Broccoli Packs Powerful Punch to Bladder Cancer Cells; Holly Wagner
- University of Pittsburgh Medical Center; Low Oxalate Diet; 2006
- National Kidney and Urologic Diseases Information Clearinghouse; What I Need to Know About Kidney Stones; April 2007
