What to Eat When You Have Chronic Kidney Disease
They’re small, but your kidneys have a mighty job—filtering out waste from the blood. If they aren’t working well things can go wrong, like unhealthy blood pressure and electrolyte levels. That's why if you have chronic kidney disease (CKD), your diet can help determine your destiny. Still, “it’s not one-size-fits-all,” warns Mohamed Atta, M.D., professor of medicine in the division of nephrology at the Johns Hopkins University School of Medicine in Baltimore. “Nutritional support is important, but you have to tailor that support based on the cause of the kidney disease.”
The Vicious Circle of CKD and Other Health Conditions
Chronic kidney disease is always caused by another condition, most often diabetes or high blood pressure (HBP), which both can damage the kidneys’ blood vessels. What's more, as CKD progresses it often leads to HBP (or makes it worse), increasing your risk for cardiovascular issues like heart attack and stroke. This is why it’s super important to eat foods that support your kidney function and lower your risk for heart problems. Here, we’ll walk you through a CKD-friendly diet. (Remember, always consult with your doctor and/or nutritionist about your own individual needs before embarking on a new eating plan.)
Try This "Heart Smart" Dietary Approach for CKD
Unless you’re already on dialysis, start with a balanced diet, says Krista Maruschak, R.D., a registered dietitian with Cleveland Clinic’s Center for Human Nutrition in Ohio. Since CKD and heart problems often go hand-in-hand, heart-smart eating helps reduce fats that build up in your kidneys, heart, and blood vessels. The general approach as you cruise your grocery store aisles? Maruschak suggests picking up lots of fruits and vegetables, whole grains, low- or no-fat dairy, lean proteins, and healthy fats such as olive and flaxseed oils. Limit saturated fats to 5% to 6% of your total daily calories and avoid trans-fats.
Skip the Salt
Now, for some specifics. “I tell my patients salt is their number-one enemy, the number-one cause of problems,” says Dr. Atta. Reducing the amount of sodium you eat can help control HBP and diabetes and lower your risk of heart problems, he adds. Keep your intake to under 2,300 milligrams (about 1 tsp.) a day, advises Maruschak. To lower your intake, buy fresh food (packaged and prepared food tends to be high in sodium); cook with herbs and spices instead of salt; rinse canned meat, beans, and veggies before eating; and check food labels—the sodium Daily Value should be under 20%.
Choose Lean Proteins and Cut Down on Red Meat
Protein creates waste that your kidneys must filter out. Eating too much of it forces damaged kidneys to work even harder, making CKD worse. Limiting protein to 0.6–0.8 g/kg of body weight is especially important in Stages 3 to 5 of CKD because such restrictions can help slow down disease progression, Maruschak says. Red meat is “a stress test to the kidney,” adds Dr. Atta. It has a surplus of saturated fat, cholesterol, and salt, and it delivers high levels of acid that your kidneys can’t remove. Choose fish, poultry, eggs, nuts, beans, and grains for your protein needs instead.
Watch Your Potassium Intake
In Stages 3 to 5 of CKD, your lab tests may start showing higher levels of potassium because your kidneys can’t filter it out, says Maruschak. High potassium can cause serious heart problems, including sudden death from your heart stopping, says Dr. Atta. Symptoms of life-threatening levels include leg weakness, chest pain, difficulty breathing, abnormal heartbeat, nausea, or vomiting. If your potassium level is too high, you’ll need to limit high-potassium foods like oranges, bananas, dairy, nuts, potatoes, beans, and whole-wheat. This can be tricky, especially on a heart-healthy diet, so you’ll probably need a dietitian’s help.
Limit Foods With Phosphorus
Like potassium, your phosphorus levels may begin to rise as your kidney function decreases. Too much phosphorus can weaken your bones, cause calcification of your arteries, and lead to heart disease. Dr. Atta says he has patients limit phosphorus once their kidney function is at 50%. Foods and drinks higher in phosphorus include dark sodas, canned and processed food, chocolate, dairy, meat, bran, and oats. These restricted low-potassium and low-phosphorus diets are “why we have patients meet with a nutritionist to make sure they know what to avoid,” Dr. Atta adds.
Bite Into Apples and Berries
One of the biggest benefits of apples and berries like strawberries and blueberries for people with CKD is that they’re extremely low in potassium, says Dr. Atta. All three—especially blueberries—also have antioxidants called anthocyanins, which, according to recent study published in Food and Nutrition Research, may help prevent heart disease, diabetes, cancer, inflammation, and obesity. They all contain fiber and vitamin C, too. Keep in mind that eating a bunch of low-potassium foods in one day can add up, so enjoy these fruits in moderation, Dr. Atta says.
Try More Omega-3-Rich Fish
Omega-3 fatty acids are an important part of a healthy diet because research has found that they can boost your heart health, lowering your risk of heart disease, blood clots, and arrhythmias. They help keep plaque out of your arteries and curb inflammation, too. Omega-3s may also lower blood pressure, a potentially big benefit when you have CKD. You have to get Omega-3 fatty acids through your food since your body doesn’t make them. The best sources are fish like salmon, herring, mackerel, lake trout, bluefin tuna, anchovies, and albacore tuna. Aim for 2+ servings a week.
Eat Right With End-Stage Kidney Disease
If you’re on kidney replacement therapy (dialysis or kidney transplant), Maruschak says you’ll need an individualized diet plan that reflects your lab work and the type of therapy you’re currently getting. In general, she says you’ll need to limit foods that are high in potassium and you may need to limit your phosphorus intake, too. You may also need to restrict your fluids and limit your sodium intake if you’re on dialysis to prevent water retention in between treatments. One small upside is that you’ll need to eat extra protein when you’re on dialysis, typically 1.2–1.5 g/kg of your body weight, she adds.
- Heart-healthy Diet: Mayo Clinic. (2019). “Heart-healthy diet: 8 steps to prevent heart disease.” mayoclinic.org/diseases-conditions/heart-disease/in-depth/heart-healthy-diet/art-20047702
- Lowering Sodium Intake: National Institute of Diabetes and Digestive and Kidney Diseases. (2016). “Eating Right for Chronic Kidney Disease.” niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/eating-nutrition
- Protein, Potassium, and Phosphorus: Centers for Disease Control and Prevention. (2019). “Diabetes and Kidney Disease: What to Eat?” cdc.gov/diabetes/managing/eat-well/what-to-eat.html
- Symptoms of High Potassium LLevels: National Kidney Foundation. (2020). “What is Hyperkalemia?” kidney.org/atoz/content/what-hyperkalemia
- Apples, Berries, and Fish: National Kidney Foundation. (2020). “7 Kidney-Friendly Superfoods.” kidney.org/content/7-kidney-friendly-superfoods
- Omega-3 Fatty Acids: Cleveland Clinic. (2019). “Omega-3 Fatty Acids.” my.clevelandclinic.org/health/articles/17290-omega-3-fatty-acids
- Kidney Replacement Therapy: National Institute of Diabetes and Digestive and Kidney Diseases. (n.d.). “Prepare for Kidney Replacement Therapy.” niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/kidney-disease/identify-manage-patients/manage-ckd/prepare-kidney-replacement-therapy