16.3: Nutrition and Chronic Renal Illness
By the end of this section, you should be able to:
- 16.2.1 Discuss the impact of nutrition on chronic renal disorders.
- 16.2.2 Discuss the impact of nutrition on acute exacerbation of chronic renal disorders.
Urologic Illnesses
Many different urologic and renal illnesses are impacted by nutrition. Some of the more common urologic illnesses —illnesses that affect parts of the renal system other than the kidneys—that can be impacted by nutrition include overactive bladder, interstitial cystitis, benign prostatic hyperplasia, and bladder cancer. Each of these has different causes and different nutritional impact based on the pathophysiology of the disease.
Overactive Bladder
Overactive bladder (OAB) , affecting more than 33 million Americans, causes urinary incontinence and urinary urgency resulting from involuntary contraction of the detrusor muscle of the bladder (Mobley et al., 2020). Anticholinergic medications and beta-3 adrenoceptor agonists are prescribed to treat this condition (Mobley et al., 2020). Some individuals also take 2–4 g of sodium bicarbonate twice daily to alkalinize the urine and make it less irritating to the bladder (Mobley et al., 2020).
Nutritional considerations for urologic illness center around reducing symptoms and avoiding medication interactions. Anticholinergic drugs should not be taken with alcohol because this combination can increase the risk for respiratory depression, unconsciousness, and death (Cafasso, 2023). Alcohol also acts as a diuretic, so clients should avoid it to prevent increased urinary frequency (Stoppler, 2020). They should also avoid carbonated beverages because they contain substances that can irritate a sensitive bladder and increase symptoms. Another important nutritional modification is to eliminate caffeine. Coffee, tea, other caffeinated beverages such as energy drinks, and brown chocolate all contain an acid that acts as a bladder irritant and aggravates OAB symptoms (Mobley et al., 2020; Stoppler, 2020).
Citrus fruits, including oranges, grapefruits, lemons, limes, and clementines, are also acidic; they can alter the urine pH and contribute to urgency and incontinence, so clients should avoid or reduce consumption of them (Mobley et al., 2020; Stoppler, 2020). Pineapple, tomatoes, wasabi, chili, spicy salsa, and other spicy condiments are all acidic foods, as are cranberries; although cranberries are beneficial for avoiding UTIs, they contain irritants that exacerbate OAB (Mobley et al., 2020; Stoppler, 2020). Sugar, artificial sweeteners, honey, grapes, bananas, apples, peaches, plums, strawberries, raw onions, dairy products (especially sour cream and aged cheeses), prunes, ketchup, vinegar, soy sauce, and mayonnaise can all contribute to an increase in OAB symptoms (Mobley et al., 2020; Stoppler, 2020). Nocturia can be decreased if individuals restrict their fluids during the day, especially after 6 p.m. (Mobley et al., 2020).
Nurses can encourage clients to try food substitutions. Dill, rosemary, thyme, and garlic are great substitutes for the more irritating spices (Stoppler, 2020). White chocolate is recommended instead of regular chocolate because it contains no caffeine, but clients should be cautioned not to eat too much because it contains sugar. Peas and carrots, along with other high-fiber foods, are encouraged to keep bowel movements regular and prevent symptoms resulting from increased pressure on the pelvic floor from constipation (Stoppler, 2020). In addition to estrogen supplementation for women with OAB symptoms related to estrogen deficiency, these clients can benefit from consuming vegetables that contain phytoestrogens, such as yams and carrots (Mobley et al., 2020). These clients should also increase their intake of potassium, protein, and, especially, vitamin D, which works to reduce urinary urgency at the site of the detrusor muscle (Mobley et al., 2020).
Another significant change clients can make is a lifestyle change, not a nutritional one: Clients who use tobacco should stop, as its use is linked with OAB symptoms (Mobley et al., 2020).
Interstitial Cystitis
Interstitial cystitis, also known as chronic pelvic pain syndrome , causes pelvic pain and a persistent desire to urinate, as well as nocturia, urinary frequency, and voiding of only small amounts at a time (Mobley et al., 2020). These symptoms mimic those of UTI, but urine cultures will consistently show no infection. Pentosan polysulfate sodium, sodium bicarbonate with calcium glycerophosphate, and dimethyl sulfoxide have all been used to treat this condition, and dietary modifications to reduce bladder irritants can effectively supplement pharmacotherapy. Nurses should give the same nutritional recommendations to clients with interstitial cystitis as for those with OAB.
Benign Prostatic Hyperplasia
Benign prostatic hyperplasia (BPH) is an enlargement of the prostate gland, affecting men (19 million in the United States) as they age and as their testosterone levels decrease. Lower urinary tract symptoms (LUTS) include urinary frequency and urgency, a weak urine stream, the feeling of being unable to empty the bladder, postmicturition dribbling, and nocturia (Mobley et al., 2020). Nutrition has not been shown to directly affect testosterone levels, but evidence indicates that the Mediterranean diet can be helpful in decreasing LUTS (Mobley et al., 2020). The Mediterranean diet promotes daily consumption of plant-based foods to replace some meats and starches, and the replacement of unhealthy fats, such as butter and margarine, with healthier fats (Modglin, 2022). This diet is rich in olive oil, small amounts of fish and other seafood, and plant-based options.
Bladder Cancer
Bladder cancer is the seventh most common form of cancer diagnosed, with the highest incidence occurring in White men (Mobley et al., 2020). Tobacco use is the greatest risk factor for the disease. Eating a diet high in isothiocyanates, which are found in cruciferous vegetables such as cabbage and kale, and drinking tea have both been linked to a decreased risk for developing bladder cancer.
Renal Illnesses
Renal illnesses are those that impact the kidney or any portion of the kidney. Many diseases can affect the kidney, and although they may have different causes and initial signs and symptoms, they will also produce very similar signs and symptoms because the diseases all impact the same organ. Common renal illnesses that can be affected by nutrition include nephrolithiasis, CKD, and renal cancer.
Nephrolithiasis
Nephrolithiasis , commonly referred to as kidney stones, can occur as a single incident or as a chronic condition. Kidney stones can cause a wide range of issues, from extreme pain to kidney failure due to hydronephrosis if they block urine flow and are not treated in a timely manner. Nurses should instruct clients to drink at least 88 oz (2.5 L) of fluids daily to help prevent stone formation (Mobley et al., 2022). Fruit juices are also recommended because they contain citrate, which inhibits calcium oxalate and calcium phosphate stone formation (Dai & Pearle, 2022).
The type of nutritional modification required depends on the type of stone and its composition (Table 16.1).
| Stone Type | Composition | Food Modifications |
|---|---|---|
|
Calcium stones
(oxalate or phosphate; 75% of stones) |
Calcium oxalate or calcium phosphate |
|
|
Uric stones
(up to 10% of stones) |
Uric acid |
|
|
Struvite stones
(5%–15% of stones) |
Mixture of magnesium, ammonium, phosphate, and calcium carbonate |
|
|
Cysteine stones
(1–2% of all stones but 6–8% of all pediatric stones) |
Cysteine |
|
Chronic Kidney Disease
Chronic kidney disease (CKD) affects more than 31 million Americans, but many remain undiagnosed because the early stages are relatively asymptomatic (Mobley et al., 2020). Many things can cause CKD, but the most common causes are diabetes types 1 and 2 and hypertension, conditions that need to be managed correctly to slow disease progression. Nutrition plays a very important role in the health of clients with CKD, even if they advance to end-stage renal disease (ESRD) and require dialysis treatment or a renal transplant to sustain life.
The stage of CKD is determined by GFR levels, which indicate how well the kidneys are filtering wastes from the blood. (See Table 15.2 in Applying Clinical Judgment to Promote Nutrition for Renal Wellness.) Creatinine and blood urea nitrogen (BUN) levels are also monitored closely and change more as the kidneys progress toward failure.
Nutritional restrictions are vital for clients with CKD. Referral to a certified renal dietician can ensure that clients are properly educated and that their nutritional needs are individualized to improve their quality and length of life.
Foods high in calcium include cheese, yogurt, edamame, canned sardines, canned salmon, tofu, almonds, leafy green vegetables, and calcium-fortified foods. Foods high in magnesium include dark chocolate, avocados, nuts, legumes, tofu, seeds, whole grains, fatty fish, bananas, and leafy green vegetables.
Phosphorus should be restricted to less than 800–1000 mg/day, protein to 0.6–0.8 g/kg/day, and potassium to less than 2000 mg/day (Mobley et al., 2020). Protein should come from lean sources as much as possible, which are those that come from low-fat, high-protein foods such as eggs and skinless chicken.
For clients receiving dialysis treatments, strict fluid restriction is extremely important because gaining too much weight due to fluid retention in between treatments can cause serious side effects. The average fluid restriction for a client on dialysis is 32 oz daily (Fresenius Kidney Care, n.d.). Nurses should instruct clients that fluids are not just beverages and substances that are liquid at room temperature; this category also includes gelatin, ice cream, ice, ice chips, and soup.
Nurses should be sure clients are aware that when a low-sodium diet is required and sodium substitution is recommended, it is dangerous for them to use salt substitutes . These substitutes are made with potassium chloride , which can raise potassium to life-threatening levels. Instead, clients should check food labels for added sodium and flavor their food with herbs and other salt-free substitutes.
Renal Cancer
Renal cancer , or kidney cancer , occurs sporadically, but associations with aging, obesity, hypertension, smoking, acquired cystic kidney disease, and exposure to asbestos, cadmium, or petroleum have been observed (Mas Que Ideas Foundation, 2022). Most of the time, renal cancer is asymptomatic and found incidentally on an abdominal scan performed for other medical purposes; however, on occasion, a client may experience hematuria, an abdominal lump, or a symptom related to paraneoplastic syndrome, such as anemia, hypertension, weight loss, anorexia, or muscle wasting. Renal cancer will not necessarily cause immediate or automatic kidney failure.
Proper nutrition and nutritional modifications can help lower the risk for renal cancer, prevent adverse effects of cancer treatments and medications, support the highest level of renal function possible, and maintain a client's life expectancy after cancer remission.
Preventing renal cancer is the first priority. Eating grilled and pan-fried foods as well as red meats increases the risk, so nurses should instruct clients to restrict or avoid these (Richards, 2022). Increased intake of vegetables, with special emphasis on cruciferous vegetables, and foods containing vitamin C, such as citrus fruits, strawberries, bell peppers, tomatoes, and white potatoes, shows promise for decreasing the risk for developing renal cancer (Liao et al., 2022). High-fiber foods; foods rich in antioxidants such as vitamin E and selenium; and foods containing phytochemicals, such as whole grains, may also reduce the risk (Thompson, 2023). See Figure 16.3.
Nutritional changes can address adverse effects of cancer treatment. Many side effects of chemotherapy —such as nausea and vomiting, anorexia, diarrhea, constipation, flatus, bloating, weight loss, sore throat, gastrointestinal problems, dysphagia, heartburn, dry mouth, mouth sores, and changes in taste and smell—make it difficult for the individual to take in enough calories. Therefore, a nutrient-dense diet with sufficient calories, vitamins, and minerals to ensure proper nutrition is important (Richards, 2022; Thompson, 2023). It should include whole foods, such as fruits, vegetables, and whole grains, and limit foods high in salt and phosphorus (Richards, 2022). Fluid volume status should be monitored because decreased kidney function may necessitate fluid restriction (Richards, 2022). Nurses can suggest that clients with painful mouth sores avoid acidic or spicy foods, alcohol, and foods that are too hot or too cold, and instead eat foods that are soft and easy to chew (Thompson, 2023).
Because of the eating issues that chemotherapy can cause, clients may better tolerate smaller, more frequent meals and maybe even different food consistencies, such as soft, lightly mashed, or pureed foods (Richards, 2022). Brief periods of fasting may even be beneficial during chemotherapy treatment because fasting can generate environments in the body that make survival of cancer cells less likely and help normal cells resist the negative effects of chemotherapy. These periods should be very short, and the client should eat calorie-rich, nutrient-dense foods after fasting.
Another significant effect of chemotherapy is the risk for developing infection. Some nutritional precautions to lower this risk include avoiding unpasteurized juice and dairy products as well as raw fish and raw meat (Richards, 2022). Food preparation and storage are also important in infection prevention, so the nurse should educate the client on appropriate methods.
In maintenance, a plant-based diet may improve survival after renal cancer (Richards, 2022). Because chronic inflammation has been shown to play a major role in cancer, and fruits and vegetables have strong anti-inflammatory properties, fruits and fiber-rich vegetables may have protective effects against renal cancer and its reoccurrence (Thompson, 2023). Since whole grains are high in fiber and contain antioxidants such as selenium and vitamin E as well as phytochemicals, they are also important nutritionally and may help prevent the occurrence and reoccurrence of renal cancer.
Holistic Assessment of Cultural Considerations
Most long-term kidney disease management is focused on CKD. Care of CKD starts with nutritional restrictions and treatment of any comorbidities to prevent disease progression, as the main goal is to prevent the need for dialysis (Satellite Healthcare, 2022). Some religious beliefs involve more restrictions in nutritional allowances and prevent the acceptance of dialysis or transplants, making it even more important for these clients to slow progression as much as possible for as long as possible.
Nurses must be well versed in the nutritional and other care needs of these clients so they can properly educate them to holistically care for their disease as well as live within the confines of their religious and cultural beliefs. Treatment adherence, quality of life, and the self-care ability of clients with CKD and ESRD increase, and risks for complications decrease, when nurses are actively involved in clients’ comprehensive care.
Promotion of Food Security
Food security must be addressed in all age groups to ensure renal health. The National Kidney Foundation has many partnerships with other organizations that are working on initiatives to address food insecurity , especially for individuals with special nutritional needs due to renal issues.
Economic status and the accessibility of grocery stores can affect people’s ability to obtain food. At least 33.2% of low-income individuals live more than a mile from the nearest grocery store (Economic Research Service, 2022). Older adults and individuals with mobility issues may have to rely on others to bring them food and therefore have even more limited food options. Having insufficient ways to obtain food from grocery stores because of transportation issues may lead some people to buy more fast food regardless of their health needs, as fast-food restaurants are often more numerous and easily accessed than grocery stores.
Americans have access to a variety of government resources that can help them with food security issues. The Older Americans Act authorizes meal services and related services for those aged 60 and older, as well as their spouses, regardless of age. These services are provided in settings such as senior centers, churches, schools, and community centers, and meals can be delivered to individuals’ homes if they have limited mobility (USDA, 2020, pp. 129–130). The Supplemental Nutrition Assistance Program (SNAP) , commonly called food stamps, is a federally funded program that helps Americans with limited incomes obtain healthy foods and beverages during times of constrained resources (USDA, 2020, pp. 68, 90, 105, 120, 129). These same groups of people can take advantage of the Commodity Supplemental Food Program , which directly provides packaged food to older Americans with limited income via federally funded resources and distribution help from nonprofit organizations (USDA, 2020, p. 130). The Child and Adult Care Food Program is a federally funded program that provides reimbursement for food served to children and older adults cared for in after-school programs and day care centers, including adult day care (USDA, 2020, pp. 68, 90, 130). The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides specific healthy foods for women who are pregnant, breastfeeding, or postpartum and for children aged newborn to 5 years (USDA, 2020, pp. 68, 90, 120). The National School Lunch Program and the School Breakfast Program provide low-income children with breakfast and lunch on school days, accounting for two-thirds of their daily caloric needs for those days (USDA, 2020, p. 90).