Learn About Potassium & CKD
Potassium is a mineral found in every tissue in our body, and it is necessary for proper kidney function, heart rhythm regulation, muscle contraction, and nerve transmission. [1] Because the kidneys are responsible for potassium balance, people living with kidney disease are at increased risk of abnormal potassium levels. Both high and low potassium levels can lead to irregular heart rhythm and severe health risks.
Many factors, including diet, can impact potassium levels. Recommended potassium intake will vary widely in people with kidney disease. Potassium is present in significant amounts in fruits, vegetables, dairy products, animal proteins, nuts/seeds, pulses, and legumes. Maintaining a varied and nutrient-dense diet is important even on a potassium restriction.
Factors that impact potassium levels
The average American adult consumes about 2,300-3,000 mg of potassium a day, but dietary intake is not the only factor that impacts levels. [1]
Here are other non-diet factors that may impact potassium levels: [1,2]
- Medications like angiotensin-converting enzyme (ACE) inhibitors or potassium-sparing diuretics.
- Other diseases and conditions include diabetes, congestive heart failure, adrenal insufficiency, liver disease, or gastrointestinal bleeding.
- Problems during blood collection.
- Bowel movement regularity and digestive transit time.
- Adequate or inadequate dialysis treatments in those with End-Stage Renal Disease (ESRD/CKD Stage 5d).
Potassium intake recommendations
Controlling potassium in the diet can feel problematic for people with kidney disease. The same nutrient-dense, high-fiber foods promoted as “healthy” for most people might seem off-limits because of potassium content. It can be even more confusing because research completed across the whole population shows that higher potassium intake may help decrease blood pressure. In contrast, low potassium intake increases the risk of high blood pressure, especially when combined with high sodium intake. [2]
That is why it is crucial to remember that the degree to which someone with kidney disease will need to limit potassium will vary significantly.
The recommendation for kidney disease patients is to maintain normal blood potassium levels, and not to follow a specific low-potassium diet. [3]
For instance, people in the early stages of kidney disease probably won’t need to limit potassium in their diet. They might benefit from a dietary pattern containing higher potassium from fruits and vegetables, nuts and seeds, fish, legumes, and whole grains. [4]
On the other hand, someone in the later stages might need to limit their intake to less than 2000 mg of potassium per day, and someone on dialysis might need a low or high-potassium diet. [2]
Each individual is different and should consult their doctor or dietitian for specific recommendations.
Considerations for the overall eating pattern
Only focusing on limiting or avoiding high potassium foods by choosing refined grains and limiting plant-based sources of potassium is not a practical approach for decreasing complications from chronic kidney disease. Instead, increasing research demonstrates that a primarily plant-based or Mediterranean-style eating pattern may lower the risk of progression in CKD (before CKD-5d) and reduce mortality risk without causing high potassium levels. [4]
Here are possible explanations for this paradox:
- Animal meats and dairy provide significant amounts of potassium. Dairy foods and larger portions of meat, fish, and poultry contribute a large amount of potassium to the diet. For many people reducing their animal-based proteins and switching to a plant-based diet will decrease their potassium intake. [2]
- Fruits and vegetables are more alkaline (higher pH), which can cause potassium to shift back into cells vs. into the blood serum. [5]
- A higher fiber diet promotes regular bowel movements. In healthy adults, 90% of potassium is excreted by the kidneys and about 10% by the colon. In late-stage CKD, the body adapts and can significantly increase excretion in the colon. Because of this, constipation can promote high potassium levels. The high fiber content of plant-based diets supports bowel regularity which can be a preventive measure against high potassium levels. [6]
Strategies for limiting potassium in the diet
If your doctor or dietitian tells you that you need to limit potassium in your diet, here are some actions you can take while still maintaining a health-promoting eating pattern.
Start by focusing on the highest sources of potassium in your diet currently.
Note the potassium guide below. Very few people will need to avoid all high-potassium foods. Now consider whether you could do any of the following three things: decrease the portion size, decrease the frequency or swap for a lower-potassium option.
Here are some examples:
- Decrease the portion size: Instead of having a half-cup of guacamole with chips, have a sliver (1/8th) of avocado on your taco. Instead of having a whole banana, split half of it with your family member. Instead of having a whole tomato, eat a few cherry tomatoes.
- Decrease the frequency: Try avoiding eating two high-potassium foods on the same day or limit very high-potassium foods to every other day.
- Swap for a lower-potassium option: Choose mandarin oranges instead of navel oranges. Choose blueberries with your oatmeal instead of a banana. Choose pesto instead of marinara sauce.
Make sure you aren’t using foods with added potassium.
Potassium added to foods in processing can be a significant source in the diet. Here are a couple of examples:
- Low-sodium foods. Many salt substitutes and foods labeled low-sodium are actually made with potassium chloride. What can you do? Look within the ingredients list for the word “potassium” and make sure the milligrams of potassium listed on the Nutrition Facts Panel fits within your daily recommendation. [2]
- Enhanced Meats. Meat and poultry products can be injected with solutions containing potassium to improve shelf-life, tenderness, and quality factors. What can you do? Try to avoid meat, fish, and poultry products labeled “basted,” “enhanced”, “injected,” “improved,” and “marinated.” [7]
Consider double boiling tuberous root vegetables like potatoes and yams
Did you know you can leach out or reduce the potassium in foods like potatoes, sweet potatoes, and yams by about 50% by double boiling? [8]
Here’s how to do it:
- Peel the vegetables and slice them into small quarter-inch pieces.
- Rinse the vegetables thoroughly.
- Fill a pot with water and add vegetables (2:1 ratio/water: vegetables).
- Bring the pot of water to a boil, then drain the water off and rinse the vegetables again.
- Fill the pot again with water (2:1 ratio), and boil until soft but integrity is retained.
- Drain the vegetables and prepare as desired.
View a more in-depth tutorial on leaching potassium here
Don’t assume “low potassium” means you can have unlimited amounts.
In general, low-potassium fruits and vegetables are considered to have <200 mg of potassium per serving. That serving size is an important consideration. Watermelon makes for an excellent example of how this can become problematic. We consider watermelon a low-potassium fruit because a 1-cup serving of diced watermelon only contains 170 mg of potassium. [9] However, watermelon is rarely served and eaten in such a small serving. Someone could easily consume 3-4 cups of watermelon during a hot summer day which means they are consuming 510-680 mg of potassium.
When it comes to beans/legumes: canned is best.
You might be surprised to find out that some processing can actually reduce potassium in foods. Generally, canned beans will contain significantly less potassium than prepared fresh or dry beans. Just remember to drain and rinse and choose no added salt canned products.
Here’s an example:
- Beans, pinto, mature seeds, cooked, boiled, without salt= 1 cup contains 746 mg potassium
- Beans, pinto, mature seeds, canned, drained solids, rinsed in tap water= 1 cup contains 395 mg potassium [10]
High-Potassium Foods > 200 mg
The portion size is ½ cup unless otherwise stated. Visit foods high in potassium article for an in-depth look. Or, play around with our food analyzer tool to inspect the kidney nutrition of all your favorite foods.
Fruits
- Apricot, raw (2 medium)
- dried (5 halves)
- Avocado (¼ whole)
- Banana (½ whole)
- Cantaloupe
- Dates (5 whole)
- Dried fruits
- Figs, dried
- Grapefruit Juice
- Honeydew
- Kiwi (1 medium)
- Mango (1 medium)
- Nectarine (1 medium)
- Orange (1 medium)
- Orange Juice
- Papaya (½ whole)
- Pomegranate (1 whole)
- Pomegranate Juice
- Prunes
- Prune Juice
- Raisins
Vegetables
- Acorn Squash
- Artichoke
- Bamboo Shoots
- Baked Beans
- Butternut Squash
- Refried Beans
- Beets, fresh then boiled
- Black Beans
- Broccoli, cooked
- Brussels Sprouts
- Carrots, raw
- Chickpeas (1 cup)
- Chinese Cabbage
- Dried Beans and Peas
- Greens, except Kale
- Hubbard Squash
- Kohlrabi
- Lentils
- Legumes
- White Mushrooms, cooked (½ cup)
Other Foods
- Bran/Bran products
- Chocolate (1.5-2 ounces)
- Granola
- Milk, all types (1 cup)
- Molasses (1 Tablespoon)
- Nuts and Seeds (1 ounce)
- Peanut Butter (2 tbs.)
- Salt Substitutes/Lite Salt
- Salt-Free Broth
- Yogurt
- Snuff/Chewing Tobacco
Foods Low in Potassium < 200 mg
The portion size is ½ cup unless otherwise stated. Visit foods low in potassium article for an in-depth look. Or, play around with our food analyzer tool to inspect the kidney nutrition of all your favorite foods.
Fruits
- Apple (1 medium)
- Apple Juice
- Applesauce
- Apricots, canned in juice
- Blackberries
- Blueberries
- Cherries
- Cranberries
- Fruit Cocktail
- Grapes
- Grape Juice
- Grapefruit (½ whole)
- Mandarin Oranges
- Peaches, fresh (1 small) canned (½ cup)
- Pears, fresh (1 small) canned (½ cup)
- Pineapple
- Pineapple Juice
- Plums (1 whole)
- Raspberries
- Strawberries
- Tangerine (1 whole)
- Watermelon (limit to 1 cup)
Vegetables
- Alfalfa sprouts
- Asparagus (6 spears raw)
- Beans, green or wax
- Broccoli (raw or cooked from frozen)
- Cabbage, green and red
- Carrots, cooked
- Cauliflower
- Celery (1 stalk)
- Corn, fresh (½ ear) frozen (½ cup)
- Cucumber
- Eggplant
- Kale
- Lettuce
- Mixed Vegetables
- White Mushrooms, raw (½ cup)
- Onions
- Parsley
- Peas, green
- Peppers
- Radish
- Rhubarb
- Water Chestnuts, canned
- Watercress
- Yellow Squash
- Zucchini Squash
Summary
So you’ve read this article, and you know that normal potassium levels are critical to human health and that it’s not controlled by diet alone. A high-fiber, plant-heavy eating pattern shows the most overall benefit for people with kidney disease and doesn’t often cause high potassium levels. If you do need to limit potassium in your diet, there are many reasonable strategies to reduce your intake.
And if you need more guidance implementing CKD diet recommendations, seek out a renal or kidney dietitian!
References
- NIH. (2016). Office of Dietary Supplements – Potassium. Nih.gov. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/
- Yamada, S., & Inaba, M. (2021). Potassium Metabolism and Management in Patients with CKD. Nutrients, 13(6), 1751. https://doi.org/10.3390/nu13061751
- Ikizler, T. A., Burrowes, J. D., Byham-Gray, L. D., Campbell, K. L., Carrero, J. J., Chan, W., Fouque, D., Friedman, A. N., Ghaddar, S., Goldstein-Fuchs, D. J., Kaysen, G. A., Kopple, J. D., Teta, D., Yee-Moon Wang, A., & Cuppari, L. (2020). KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. American journal of kidney diseases : the official journal of the National Kidney Foundation, 76(3 Suppl 1), S1–S107. https://doi.org/10.1053/j.ajkd.2020.05.006
- Kelly, Jaimon T et al. “Healthy Dietary Patterns and Risk of Mortality and ESRD in CKD: A Meta-Analysis of Cohort Studies.” Clinical journal of the American Society of Nephrology : CJASN vol. 12,2 (2017): 272-279. doi:10.2215/CJN.06190616
- Di Iorio, B. R., Di Micco, L., Marzocco, S., De Simone, E., De Blasio, A., Sirico, M. L., Nardone, L., & UBI Study Group (2017). Very Low-Protein Diet (VLPD) Reduces Metabolic Acidosis in Subjects with Chronic Kidney Disease: The “Nutritional Light Signal” of the Renal Acid Load. Nutrients, 9(1), 69. https://doi.org/10.3390/nu9010069
- Sumida, K., Yamagata, K., & Kovesdy, C. P. (2019). Constipation in CKD. Kidney international reports, 5(2), 121–134. https://doi.org/10.1016/j.ekir.2019.11.002
- Sherman, R. A., & Mehta, O. (2009). Phosphorus and potassium content of enhanced meat and poultry products: implications for patients who receive dialysis. Clinical journal of the American Society of Nephrology : CJASN, 4(8), 1370–1373. https://doi.org/10.2215/CJN.02830409
- Burrowes, J. D., & Ramer, N. J. (2006). Removal of potassium from tuberous root vegetables by leaching. Journal of renal nutrition : the official journal of the Council on Renal Nutrition of the National Kidney Foundation, 16(4), 304–311. https://doi.org/10.1053/j.jrn.2006.07.012
- U.S. Department of Agriculture. (2019, April 1). Watermelon, raw. FoodData Central. Retrieved April 10, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/167765/nutrients
- U.S. Department of Agriculture. (2011, April 1). Beans, pinto, canned, drained solids. FoodData Central. Retrieved April 10, 2022, from https://fdc.nal.usda.gov/fdc-app.html#/food-details/174286/nutrients
