Type 2 diabetes is the leading cause of renal disease, and up to 40 percent of diabetics develop kidney failure, according to Harvard's Joslin Diabetes Center. High blood sugars damage blood vessels and nerves that support kidney function. Stabilizing your glucose levels and eating a diet that doesn't tax your kidneys will help slow the progression of kidney disease and delay your need for dialysis.
Sodium
Both diabetes and renal diets limit your sodium intake to help reduce blood pressure. One of the consequences of chronic high glucose levels is a weakening of blood vessels, which is why people with diabetes tend to have nerve damage -- called neuropathy -- and organ failure. Blood flow becomes insufficient over time, and since blood carries oxygen and vital cell nutrients, without the proper blood flow, organs can't function. In addition, your kidneys regulate the fluid balance in your body; too much sodium makes your body retain water, which can lead to edema -- painful swelling of your extremities.
Carbohydrates High in Potassium
If you're following a diabetic diet, you're probably limiting your carb intake and choosing low-glycemic-index carbs that have minimal impact on your blood sugar. Although a renal diet won't cause you to further reduce your carb intake, you will have to avoid carbs that are high in potassium. Fruits high in potassium include banana, melon, kiwi, nectarine, orange, papaya and dried fruits. Vegetables high in potassium include Brussels sprouts, beets, spinach, tomato, pumpkin and sweet potato. One major change from a diabetic diet to a renal diabetic diet is the switch from whole grains to refined grains. Although the fiber in whole grains slows the absorption of glucose into your bloodstream, the high potassium content of brown rice and unrefined grains is too much for your kidneys to process. Choose white bread and white rice on a diabetic renal eating plan.
Dairy
The high potassium, phosphorous and calcium content in dairy limits cheese, yogurt and milk on a renal diet. Although diabetics are often encouraged to simply choose low-fat dairy products, on a diabetic renal diet you'll avoid almost all dairy products. You can use nondairy creamer in your coffee, nondairy whipped topping with fruit as a snack or dessert and a milk substitute, such as rice milk, for your iron-fortified breakfast cereal. Cottage cheese and sorbet are allowed in moderation, but use olive oil instead of butter. and try to consume less than 8 oz. of dairy daily.
Protein
Digesting and processing protein can strain your kidneys; therefore, most renal diets limit protein consumption. Both diabetics and those with kidney disease are at a greater risk for high cholesterol, hardening of the arteries and heart disease. A diabetic renal diet includes limited amounts of high-quality protein that is low in saturated fat. Seafood, poultry, eggs and fish high in omega-3 fatty acids are especially good protein choices on a diabetic renal diet. Renal patients, unlike diabetics, must also limit protein from legumes and nuts because of their high potassium content. Protein is only limited for renal patients not yet on dialysis; once dialysis begins, protein needs increase.
