In their infamous bean shape, the kidneys are small but mighty organs. They’re responsible for many vital functions within the body, including (but not limited to): filtering waste products, producing urine, releasing certain hormones, and balancing bodily fluids.1
Unfortunately, there are several ways these vital organs can be damaged. Diabetes and high blood pressure are two of the most common culprits for kidney harm, but other factors can also stress these critical organs. For example, smoking, obesity, gender, age, and genetics can all increase the risk of kidney disease.
Just as our kidneys help to care for us, we have to take care of them too. In this article, we will discuss nutrition’s impact on kidney function and review some kidney-healthy foods, so you can design a renal-friendly diet that fits your needs.
How Your Diet Relates to Your Kidneys
As research points to the connection between diet and chronic disease, we can reduce inflammation by changing our nutritional intake. Thankfully, certain whole foods can help prevent or protect against fatty acid oxidation, which occurs when the oxygen in your system reacts with the fat in your blood and cells.
Why would we want to avoid fatty acid oxidation? I’m glad you asked! Oxidation is a normal process needed for many chemical reactions within the body. However, excessive oxidation of fats and cholesterol can create “free radicals” that can ultimately damage your cells, proteins, and genes.
Oxidative damage can lead to heart disease, Alzheimer’s disease, cancer, Parkinson’s disease, and other chronic conditions. Antioxidant-rich foods can help neutralize free radicals and help protect the body against inflammation.
The good news? Many foods that help protect against oxidation are kidney-friendly and can be excellent choices for people on dialysis or people with chronic kidney disease (CKD).
Since people with kidney disease experience inflammation more frequently, it’s especially important to prioritize a well-balanced diet. So, let’s talk about CKD diet tips.
What is the Renal Diet?
Individuals with compromised kidney function must be especially mindful of their nutrition to reduce the amount of waste in their blood. When the kidneys aren’t filtering waste efficiently, it can build up in the blood and negatively affect other aspects of health.
A renal diet can help support healthy kidney function and even slow the progression of kidney failure. Generally, the renal diet is low in sodium, phosphorus, and protein. It emphasizes the importance of high-quality protein and usually recommends limiting fluids. Some people may need to moderate their potassium, magnesium, and calcium intake, but that may depend on the severity of the disease.
The renal diet is often combined with other dietary restrictions to help manage blood sugar levels, lower blood pressure, and reduce blood cholesterol. It’s common to see the renal diet pair with diabetic or cardiac restrictions.
However, it’s important to remember that no two bodies are identical, and nutrition needs are individualized. Consider working with a registered dietitian with a background in kidney health to design a meal plan that addresses your specific wellness needs.
Renal Diet Food List: 12 Best Foods for Kidney Health
Planning a low-sodium, low-potassium, and low-phosphorus diet can feel overwhelming. Throw concerns about protein intake into the mix, and it can feel like the kitchen is upside down.
Here is a renal diet food list to get you started:
Cauliflower is a nutritious vegetable packed with various nutrients, including vitamin C, vitamin K, and folate. In addition, it’s an excellent fiber source and contains anti-inflammatory compounds, such as indoles.
Are you looking for a low-potassium alternative to mashed potatoes? You can try mashed cauliflower as a side dish to your favorite meal.
- 32.1 mg of sodium
- 47.1 mg of phosphorus
- 320 mg of potassium
- 16 mg of magnesium
- 23.5 mg of calcium
Cabbage is a cruciferous vegetable loaded with vitamins and minerals, such as vitamin C, vitamin K, and many B vitamins. Plus, it’s low in potassium, phosphorus, and sodium and provides insoluble fiber that helps support healthy bowel movements.
Since cabbage has a mild taste, it can be added to many dishes. For example, add it to your next stir fry or pasta sauce to increase your veggie and fiber intake.
- 12.6 mg of sodium
- 18.2 mg of phosphorus
- 119 mg of potassium
- 8.4 mg of magnesium
- 28 mg of calcium
Onions are incredibly versatile in the kitchen. Including onions in a dish can be a great way to add sodium-free flavor to a renal-friendly recipe.
Onions are high in vitamin C, B vitamins, and prebiotic fibers that help support a healthy digestive system. Consider adding some sautéed onions to your next savory or umami dish.
One small onion (70 g) provides4:
- 12.6 mg of sodium
- 20.3 mg of phosphorus
- 102 mg of potassium
- 7 mg of magnesium
- 2.8 mg of calcium
While many leafy greens are high in potassium, arugula is not. This nutrient-dense green is low in potassium, making it ideal for a kidney-friendly salad or side dish to your favorite meals.
The veggie is a good source of vitamin K and manganese and contains nitrates, which have been shown to reduce blood pressure.5
One cup of arugula provides6:
- 5.4 mg of sodium
- 10.4 mg of phosphorus
- 73.8 mg of potassium
- 9.4 mg of magnesium
- 32 mg of calcium
Blueberries can be a delicious and nutritious addition to a kidney-friendly diet. These berries contain antioxidants, such as anthocyanins, and are low in sodium, potassium, and phosphorus.
The best part? You can enjoy them straight from the fridge. Eat them fresh, or include them with some of your favorite renal-friendly baked goods.
- 1.5 mg of sodium
- 17.8 mg of phosphorus
- 114 mg of potassium
- 8.9 mg of magnesium
- 8.9 mg of calcium
Red grapes are a tasty little fruit, but don’t let their size fool you. They are packed with nutrients. They contain a significant amount of vitamin C and antioxidants called flavonoids, which are linked to reduced inflammation.8
You can enjoy fresh red grapes or freeze them for a delightful snack on a warm day.
- 7 mg of sodium
- 25 mg of phosphorus
- 225 mg of potassium
- 8.6 mg of magnesium
- 10 mg of calcium
Cranberries are known for the health benefits they offer the urinary tract. They contain phytonutrients called A-type proanthocyanidins, which help prevent bacteria from sticking to the urinary tract and bladder, thus helping to prevent infection. This can be especially beneficial for those with kidney disease since they have an increased risk of urinary tract infections.
Cranberries have a tart flavor and can be enjoyed in various ways. They can be eaten fresh, dried, or cooked. Or, if you prefer, you can enjoy it as a beverage in the form of cranberry juice.
- 2 mg of sodium
- 11 mg of phosphorus
- 80 mg of potassium
- 6 mg of magnesium
- 8 mg of calcium
While egg yolks are very nutritious, they tend to be high in phosphorus. So, if you’re looking for breakfast food low in phosphorus, consider making egg whites.
Egg whites are an excellent way for those on dialysis to meet their protein needs without skewing their electrolyte intake.
- 109.6 mg of sodium
- 9.9 mg of phosphorus
- 107.6 mg of potassium
- 7.3 mg of magnesium
- 4.6 mg of calcium
Sea bass, a high-quality protein source, is rich in healthy fats called omega-3 fatty acids. Omega-3s have been found to help reduce inflammation and even decrease the risk of cognitive decline, anxiety, and depression when incorporated into a balanced diet.
Most seafood tends to have high phosphorus levels, but sea bass is typically lower in comparison. Pan-fried is the most popular way to enjoy this fatty fish, but it can be cooked in many ways.
- 74 mg of sodium
- 211 mg of phosphorus
- 279 mg of potassium
- 45 mg of magnesium
- 11 mg of calcium
Skinless chicken breast
Chicken is one of the more easily accessible sources of protein. But did you know skinless chicken breast contains less phosphorus, sodium, and potassium than chicken with the skin on?
With kidney health in mind, it’s best to buy fresh chicken and prepare it at home to your liking. Unfortunately, pre-made rotisserie chicken is high in sodium and can negatively affect kidney function.
- 64 mg of sodium
- 196 mg of phosphorus
- 220 mg of potassium
- 24.9 mg of magnesium
- 12.9 mg of calcium
Whole wheat and whole grain products are typically high in phosphorus, but bulgur is a kidney-friendly alternative. In addition, the grain contains B vitamins, manganese, and iron, among other essential nutrients.
It’s also a vegan-friendly plant-based protein source, rich in dietary fiber. You can enjoy it in various recipes, such as stews or salads.
- 4.6 mg of sodium
- 36.4 mg of phosphorus
- 62 mg of potassium
- 29.1 mg of magnesium
- 9.1 mg of calcium
Olive oil is a phosphorous-free healthy fat, often used in cooking. The high-calorie oil can be especially beneficial for those with advanced CKD, as many have difficulty maintaining their body weight.
Moreover, the monounsaturated fat in olive oil, called oleic acid, has anti-inflammatory properties.15
One tablespoon of olive oil provides16:
- 0.3 mg of sodium
- 0 mg of phosphorus
- 0.1 mg of potassium
- 0 mg of magnesium
- 0.1 mg of calcium
Tips on How to Improve Kidney Function
Nutrition plays a significant role in kidney health, especially for those living with kidney diseases. Thankfully, we can be proactive with our health and choose foods that support kidney function. For example, a healthy diet can help slow the progression of the disease for those in the early stages of kidney disease.
Of course, it’s important to remember that no two people have the same nutrition needs, and dietary restrictions largely depend on the severity of the disease.
Consider these tips as you plan your kidney-friendly meals:
Reduce sodium intake
The kidneys filter excess sodium from your system, but when your body has too much sodium, the kidneys can’t keep up. To avoid stressing your kidneys and help control your blood pressure, the National Kidney Foundation recommends monitoring your sodium intake.
Avoid using salt both when cooking and seasoning
Use spices, herbs, and sodium-free seasonings (like garlic... yum!) instead of the salt shaker. However, it’s important to note that some sodium-free seasonings contain a comparable amount of potassium in place of sodium.
Look for unsalted options or low-salt
Look for the low-salt or unsalted versions of everyday food items to lower your sodium intake while enjoying your favorite foods.
Escape ultra-processed foods
Since sodium can act as a preservative in processed foods, like soups and frozen dinners, which tend to be loaded with the mineral. Try to cook from scratch as much as possible since you know everything that goes into the dish.
Try to limit or avoid alcohol and other foods and beverages that add stress to the kidneys.
Eat the right amount of protein
Excess protein in your system puts more stress on your kidneys. Work with your registered dietitian to determine your nutritional needs and plan your meals and snacks accordingly.
Read food labels
The nutrition facts on food labels can be especially helpful for those navigating CKD or other kidney concerns. Be mindful of the serving size and keep track of your potassium, phosphorus, and sodium intake.
Learn More About Nutrition and Healthy Eating with Signos’ Expert Advice
Nutrition plays a significant role in our overall wellness, especially regarding kidney health, and continuous glucose monitoring can help support healthy eating habits. Keeping track of your body’s reactions to your nutritional intake can help you prioritize the foods that serve your body well.
If you have questions about your nutrition needs or what renal diet foods to avoid, consider talking with your healthcare provider or registered dietitian. And in the meantime, we invite you to learn more about healthy eating through expert advice on the Signos’ blog. Take our short quiz to find out if Signos is right for you!
Topics discussed in this article:
- How Your Kidneys Work. National Kidney Foundation. (2015). Retrieved December 19, 2022, from https://www.kidney.org/atoz/content/howkidneyswork
- Fooddata Central Search Results: Cauliflower. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/169986/nutrients
- Fooddata Central Search Results: Cabbage. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/169975/nutrients
- Fooddata Central Search Results: Onion. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/170000/nutrients
- Gee, L. C., & Ahluwalia, A. (2015). Dietary Nitrate Lowers Blood Pressure: Epidemiological, Pre-clinical Experimental and Clinical Trial Evidence. Current Hypertension Reports, 18. https://doi.org/10.1007/s11906-015-0623-4
- Fooddata Central Search Results: Arugula. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/169387/nutrients
- Fooddata Central Search Results: Blueberries. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/171711/nutrients
- Kozłowska, A., & Szostak-Wegierek, D. (2014). Flavonoids--food sources and health benefits. Roczniki Panstwowego Zakladu Higieny, 65(2), 79–85.
- Fooddata Central Search Results: Red Grapes. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/2346412/nutrients
- Fooddata Central Search Results: Cranberries. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/171722/nutrients
- Fooddata Central Search Results: Egg Whites. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/172183/nutrients
- Fooddata Central Search Results: Sea Bass. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/173694/nutrients
- Fooddata Central Search Results: Chicken Breast. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/171477/nutrients
- Fooddata Central Search Results: Bulgar. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/170287/nutrients
- Carrillo, C., Cavia, M.delM., & Alonso-Torre, S. (2012). Role of oleic acid in immune system; mechanism of action; a review. Nutricion hospitalaria, 27(4), 978–990. https://doi.org/10.3305/nh.2012.27.4.5783
- Fooddata Central Search Results: Olive Oil. FoodData Central. (2019, April 1). Retrieved December 20, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/171413/nutrients