It’s a fact: Kidney disease is becoming more common—and diet is a major reason.
While some cases of kidney disease happen because of genetics and other conditions, the two main causes of kidney disease in the United States are high blood pressure and diabetes, said Marlei Simon, a transplant dietitian at the Augusta University Transplant Center.
Today, nearly half of all adults in the United States have high blood pressure. Almost 10 percent of us have diabetes. As a result, about 14 percent of us are living with kidney disease today, with 468,000 of us on dialysis and another 193,000 of us living with a kidney transplant.
A healthy diet focused on whole grains, fruits, vegetables, lean protein and dairy is the prescription for overall good health—and may help reduce the risk of developing high blood pressure, diabetes and kidney disease.
But once your kidneys have been damaged due to genetics or these diseases, that’s when what you eat becomes even more important—just not in the way you might think.
A different kind of diet
Patients with kidney disease need to monitor their diets for excessive intakes of sodium, potassium and phosphorus. That’s because when the kidneys aren’t working as well, it’s harder for patients with chronic kidney disease to excrete these minerals and manage their blood pressure.
Every patient is different, and a patient’s diet is dependent upon their medications and other conditions he or she may have. However, one thing that is pretty common across the board is that these patients need to reduce their sodium intake.
To reduce salt to 2,400 milligrams or less per day, experts advise:
- Use herbs instead of salt to season foods
- Read food labels, and stick to foods that have less than 300 milligrams of sodium per serving. Also, make sure salt isn’t one of the first items on the ingredient list.
- Avoid processed meats, like ham, bacon, sausage, hot dogs, lunch meat, chicken tenders or nuggets. And buy fresh meats that are not pre-seasoned or packaged in a solution.
- Make sure canned soups, canned vegetables and other packaged foods are low sodium or no salt added.
Potassium is a part of many of the healthy foods we eat every day, and most of us eat 8,400 milligrams or more every day. But if you have chronic kidney disease and you are not on dialysis, you may need to cut back to 2,400 milligrams per day. Watching your fruit and vegetable intake is important since a majority of our dietary potassium comes from these sources. Low-potassium fruits and vegetables include:
On the flip side, you’ll want to avoid or limit these high-potassium foods:
- Coconuts and coconut water
- Certain cereals like bran cereals and granola
- Cooked greens like beet greens, spinach, kale, collards or Swiss chard
- Brussels sprouts
- Oranges, orange juice and nectarines
- Potatoes, sweet potatoes and potato chips
- Prunes and prune juice
- Tomatoes, tomato juice or vegetable juice
Phosphorus is another common mineral that can build up in the blood when kidneys aren’t working properly. All that extra phosphorus can start a process that actually pulls calcium from your bones, making them weaker and easier to break. This is referred to as chronic kidney disease bone mineral disorder. So on the renal diet, you’ll need to:
- Limit dairy, which is high in phosphorus. A good swap is almond milk or almond-milk-based products.
- Limit beans, nuts and seeds.
- Limit cereals like bran, wheat, oatmeal and granola.
- You may need to choose white bread instead of whole grain bread if your nephrologist tells you that your phosphorus or PTH (parathyroid hormone) is elevated.
- If you have to have soda, drink only clear sodas. Darker versions are higher in phosphorus.
- Beer also contains phosphorus, so take it off your list of alcoholic drinks.
Simon is honest: The diet can be tough for patients. “But what I tell patients is to focus on what they can eat, not what they can’t,” said Simon. “And to remember, everything in moderation.”
Working with a registered dietitian can be a huge help in figuring out how to personalize the diet and make it work for you and your own tastes. For example, if you love bananas, you can have one, but make sure to avoid potassium-rich foods the rest of the day. If you have always enjoyed a bran cereal with milk for breakfast, you can swap out the cereal for Frosted Flakes and keep the milk. Or, if you love yogurt and granola, find an almond milk yogurt and top it with half granola, half puffed rice cereal.
Eating lower protein has also been shown in studies to slow down the progression of kidney disease. The exact amount of protein that a person with kidney disease needs per day is dependent on age, weight and other medical diagnoses. So talking with an registered dietitian can also help you determine your protein needs and if your diet is adequate or excessive in protein and other minerals.
Does the diet change when you’re on dialysis…or after a transplant?
For kidney patients on dialysis, here’s where your diet does a flip. You’ll stick to low sodium, phosphorus and potassium, but you’ll need to change to a high-protein diet to maintain optimal protein levels since dialysis removes protein from the blood and can be taxing on your body.
After a transplant, one of the benefits of a new kidney is that patients’ diets aren’t as limited. “The diet goes back to normal for the majority of our patients,” said Simon.
But if your “normal” used to be fast food and processed foods, that’s not exactly what we mean. “You’ll still need to follow a diet that’s lower in sodium and lower in added sugars,” said Simon. “Studies do show that practicing healthy weight management and good glucose and blood pressure control may increase the longevity of the transplanted kidney.”
Pay attention to what you’re eating
Simon suggests patients visit resources like Eatright.org to find out more about the renal diet.
But she emphasizes that slowing the progression of kidney disease by eating a healthy diet is one of the best things to do. “With the way our food industry is now and our American eating patterns, it’s not uncommon to have patients very young now, even in their 20s, with chronic kidney disease secondary to type 2 diabetes mellitus or high blood pressure,” said Simon.
Kidney disease can have symptoms, like poor appetite and feeling tired. But sometimes it happens without any symptoms, until the person ends up in the emergency room. “That’s why prevention and maintaining routine contact with your primary care physician is so important,” she said.