How kidney disease affects nutrition

Charleswood

Patients diagnosed with kidney disease are often instructed to follow a special diet. The kidneys function as the body’s filter removing toxins that build up in our system. When they lose function, these toxins accumulate, making patients ill and sometimes even causing death.

There are five stages of kidney disease. At stages 1 and 2, no restrictions are necessary except to eat healthier and control weight. By the time a patient is at stages 3-5, and having dialysis, dietary restrictions are often required, depending on appetite and weight. Potassium, phosphorus, sodium and fluids may need to be adjusted based on the patient’s status. Potassium is a mineral found in many foods and beverages which affects heart and muscle function. When kidneys work properly, potassium is kept in check in our bloodstream. In kidney failure, potassium builds up and can cause heart irregularities ,or stop your heart.

Examples of high potassium foods include processed meats and foods; bananas, oranges, melons, tomatoes, dried fruits, lentils and pulses, chocolate and whole grains. New studies have shown that processed foods have the most significant impact on potassium levels because they are more easily absorbed. Phosphorus is another mineral that can build up usually in the skin, blood vessels and organs. Too much phosphorus can affect circulation, bone health and itching.

Phosphorus is found in many foods, but dairy items contain high amounts, so these products are often limited in kidney diets. Again, phosphorus found in additives used in processed foods is more readily absorbed, like potassium, and therefore such foods must be avoided. Many patients will be on phosphate binders, such as calcium carbonate, to draw phosphorus out of their food.

Sodium causes fluid retention and can negatively affect blood pressure and cause swelling (edema). Processed, packaged and fast foods contain the most amount of salt. To reduce your salt intake, you should consume more fresh, frozen and lower salt canned foods.

Later-stage renal patients on dialysis will be instructed to avoid salty snacks, junk-type foods, canned or instant soup and sauces, V8 or tomato juices, salty meats such as bacon, sausages and ham and to replace their salt shakers with more natural flavourings.

Whether or not you have kidney or heart disease, I would recommend that everyone cuts down on salt intake. Salt is an acquired taste and once you start to reduce salt, your tastebuds will adjust for the better. Read labels and watch for ingredients like monosodium glutamate (MSG), sodium benzoate, sodium bicarbonate, sodium phosphate, sodium saccharin, soy sauce. Use garlic and onion powders versus garlic and onion salts.

Fluid restrictions are sometimes necessary in end-stage kidney disease to help reduce retention. It is important that patients meet with a registered dietitian to discuss what they need to do to control their renal failure. Patients diagnosed with kidney failure are usually referred to an RD for nutrition guidance through renal clinics and dialysis programs. Dietitians of Canada and Dial a Dietitian (204 788-8248) are other sources of reliable nutrition information.