Effect of Diet on Kidneys

Kidney disease has not reached the epidemic proportions of obesity and type 2 diabetes, but the National Kidney Foundation says its incidence is on the rise. Prevention is key for reducing kidney disease, also known as renal disease. Mostly, that means controlling the major risk factors: diabetes, high blood pressure (hypertension) and cardiovascular disease. Medications can be useful for some conditions; health care providers recommend dietary adjustments as well.

Targeting Risk Factors

Eating a diet that keeps blood-sugar levels stable is healthy for anyone, especially diabetics who are at greater risk for kidney disease. This means emphasizing vegetables, fruits and whole grains, which are naturally low in fat and rich with nutrients.
The DASH Diet is a popular eating plan for people who want to reduce high blood pressure. DASH stands for Dietary Approaches to Stop Hypertension. The American Heart Association and the National Heart, Lung and Blood Institute approve of the diet, which is rich in fruits and vegetables and promotes low-fat or non-fat dairy.
A Mediterranean diet--high in monounsaturated fat, plant proteins, whole grains and fish--is associated with a reduction in the development of heart disease and stroke.

Protein

The body needs protein to help repair muscles and fight disease. Defective kidneys struggle to separate protein from wastes in the blood, so people with kidney disease usually have to watch their protein intake.
"There's pretty good evidence that if you're on a high protein diet, like many Americans are, that can cause a rapid loss of kidney function," says Dr. Joseph Vassalotti, the National Kidney Foundation's chief medical officer. He does not, however, recommend patients follow protein-restricted diets without the recommendation of a physician and the supervision of a dietitian.
Meat is a primary source of protein. Other foods high in protein include eggs, milk, nuts and beans.

Salt

A diet high in sodium, or salt, can raise a person's blood pressure, which is why people with kidney disease usually must limit foods containing high levels of sodium.
Read nutrition labels to be sure, but foods usually high in salt include snack foods (such as chips, pretzels and popcorn), soups, processed cheeses, luncheon meats (such as ham and salami), pickles, olives, frozen dinners and canned food.

Cholesterol

A high-fat diet can lead to high levels of cholesterol in the blood. Cholesterol can build up on the walls of blood vessels and lead to heart attack or stroke, two primary killers of people with kidney disease.

Potassium

Diseased kidneys may not be able to remove excess potassium, a mineral found in fruits and vegetables, including oranges, potatoes, dried fruits, dried beans and peas, and nuts. In people with very poor kidney function, high potassium levels can affect heart rhythms, warns the National Institute of Diabetes and Digestive and Kidney Diseases.

Phosphorus

Phosphorus levels can be of concern to people with kidney disease because diseased kidneys may have trouble removing phosphorus from the blood. High levels of phosphorus can lead to the loss of calcium from bones, which can weaken them.
The National Kidney Foundation recommends eating fewer foods with high phosphorus content, including milk, cheese, pudding, yogurt, ice cream, nuts and peanut butter, cocoa, beer, colas, and dried beans and peas, such as kidney beans, split peas and lentils.

What to Eat

Kidneys will appreciate lean meats, especially fish, and monounsaturated and polyunsaturated fats, including olive oil, canola oil and safflower oil.
Among fruits, best bets are peaches, grapes, pears, cherries, apples, berries, pineapple, plums, tangerines and watermelon.
Good vegetable choices include broccoli, cabbage, carrots, cauliflower, celery, cucumber, eggplant, green and wax beans, lettuce, onion, peppers, watercress, zucchini and yellow squash.