Your kidneys, while small, are among the hardest working organs. As a part of your body’s natural detoxification system, they’re responsible for removing waste and extra fluids from your body. But that’s not all these two bean-shaped organs do. They also control blood pressure, orchestrate the creation of red blood cells, make vitamin D to support bone health, and balance the body’s pH levels. (10) To maintain healthy kidney function, it’s important to provide them with the key nutrients they need to function optimally.
A healthy, nutrient-rich diet can enhance the performance of your kidneys, especially if you have a propensity for kidney stones or are at risk of kidney disease. Poor food choices, on the other hand, can put stress on the kidneys. Here’s the breakdown of the top foods for kidney health and what to avoid for healthier kidneys.
Best foods for kidney health
Studies support eating a healthy, whole foods diet such as the anti-inflammatory Mediterranean diet or the low-sodium DASH diet. (4)(16) Both of these diets are high in lean protein, fresh fruits and vegetables, and healthy fats that support kidney function. They also both tend to be more alkaline rather than acidic, which may help the kidneys as they work to balance the body’s pH. (17) While a balanced diet helps to support overall kidney health, there are a number of foods that can be included in your diet to further support kidney function. Here are nine of the best foods for kidney health.
Apples are a rich source of pectin, a soluble fiber that supports healthy cholesterol and blood sugar levels. According to preliminary research, pectin also boosts important antioxidants in the kidneys. One study in the journal Biomedicine & Pharmacotherapy found that apple pectin, taken as a supplement, increased superoxide dismutase (SOD), glutathione peroxidase, and catalase activity in the kidneys by 5%, 7%, and 31%, respectively. (18)
Dubbed a “superfood” by many nutritionists, blueberries possess antioxidant and anti-inflammatory properties that can benefit kidney health. They’ve also been found to increase renal blood flow and important blood markers of kidney health such as glomerular filtration rate in rodent studies. (9)
Cabbage—or more specifically cabbage or sauerkraut juice—has been shown to enhance the activity of key enzymes that may prevent kidney cancer in much the same way compounds in other cruciferous vegetables like broccoli do. (22) Cabbage is also a good source of vitamin C and vitamin K, as well as many of the B vitamins. (25)
Anyone who’s ever suffered from a urinary tract infection (UTI) is likely familiar with cranberries. But the perks these tart berries provide aren’t just limited to the bladder. They can also help prevent kidney infection thanks to a plant compound called A-type proanthocyanidin. This compound may help to prevent bacteria from sticking to the lining of the bladder and the kidneys. (5) Cranberries are especially helpful for people with kidney disease as they are at greater risk of experiencing UTIs. (20)
Eggs are an excellent source of high-quality protein. They are also rich in leucine, lutein, and zeaxanthin, antioxidants that support kidney health. (14) However, if you have been diagnosed with chronic kidney disease (CKD), be sure to consult with your practitioner about your protein intake. Some experts recommend sticking to egg whites as the yolk is high in phosphorus, a mineral that compromised kidneys have trouble removing. Over time, excess phosphorus can cause your body to pull calcium from your bones and deposit it in places like your arteries, heart, or eyes where it doesn’t belong. (24)
6. Fatty fish
Fatty cold-water fish like salmon, tuna, sardines, or anchovies are high in omega-3 fatty acids. These beneficial fats possess anti-inflammatory properties that may help protect kidney function, especially as you age. (7) Omega-3s may also help reduce blood pressure, which is a key risk factor for kidney disease, and reduce the risk of end-stage kidney disease in people with CKD. (8)
Did you know? Enjoying omega 3-rich fish regularly can provide your kidneys with important anti-inflammatory benefits. (15)
7. Olive oil
This popular oil is high in oleic acid, which may help reduce inflammation throughout the body—including the kidneys. According to one Spanish study, a diet rich in extra-virgin olive oil could play a protective role against kidney injury. (1)
8. Shiitake mushrooms
Lentinula edodes (Shiitake), a savory mushroom, is an excellent source of the B vitamins, selenium, copper, manganese, and beta-glucan. Beta-glucan is a unique type of soluble fiber with immune-boosting properties that animal research suggests is especially protective of the kidneys. In rats fed L. edodes, serum urea nitrogen (a biomarker of kidney function) was reduced, indicating that shiitake may improve kidney function. (21)
9. Sweet potatoes
Sweet potatoes contain vitamins and minerals that can help balance sodium levels and may reduce its negative effects on the kidneys. One less common type of sweet potato—the purple sweet potato—contains a variety of antioxidant phytochemicals that contribute to its purple hue. Consumption of these phytochemicals demonstrated kidney protection by reducing free radical damage in rodents with type 2 diabetes. (29) However, because sweet potatoes are high in potassium, they may not be appropriate for those with CKD. (12)
Hydrate for healthy kidneys
Along with eating a healthy diet that includes these kidney-supportive foods, it’s also important to stay hydrated. Drinking a sufficient amount of water not only helps ensure that the mineral levels in urine aren’t overly concentrated, but it also helps prevent common kidney problems like UTIs and kidney stones. (19)(28) In fact, dehydration has been shown in epidemiological studies to be an important—and common—risk factor for recurrent kidney stones. (23)
The Institute of Medicine estimates that, on average, men need approximately 3 liters (13 cups) of H2O and women need about 2.2 liters (9 cups) daily. (3) However, be aware that everyone’s needs are slightly different based on age, exercise intensity, the climate in which you live, overall health, and for women, whether they are pregnant or breastfeeding. A good rule of thumb is to look at your urine. If it is dark yellow, that indicates that you are dehydrated and you need to increase your water intake. (11)
Did you know? About 60% of your body weight is made up of water. (27)
Foods to limit or avoid for kidney health
While many foods support kidney health, there are some you should either eat in moderation or avoid, even if you don’t have kidney problems. Generally, eating foods that are extremely high in sodium not only taxes the kidneys, they may also increase the risk of high blood pressure—one of the most common causes of CKD. What’s more, a diet high in salt alters your sodium balance, which can put a strain on the kidneys. (2) Here are some foods that are especially high in sodium:
- Canned foods
- Condiments, dressings, and sauces
- Packaged, convenience, or pre-made foods
- Processed meats
- Salty snacks like chips or pretzels (26)
While limiting these foods is good advice for everyone, if you have been diagnosed with kidney disease, talk with your health care provider about your diet since some otherwise healthy foods that are high in phosphorus and potassium, such as cashews or tomatoes, may also cause problems. (13)
Did you know? Research shows that a diet high in processed and fried foods is associated with a higher mortality rate from kidney disease, while a diet rich in fruits and vegetables appears to be protective. (6)
The bottom line
When it comes to maintaining kidney health, what you eat really does matter. Taking a proactive approach with a diet that contains plentiful amounts of fruit, vegetables, eggs, and omega 3-rich fish can support healthy kidney function and may help to prevent future UTIs, kidney stones, and even CKD.
- Aparicio-Soto, M., Sánchez-Hidalgo, M., Cárdeno, A., Rosillo, M. Á., Sánchez-Fidalgo, S., Utrilla, J., Martín-Lacave, I., & Alarcón-de-la-Lastra, C. (2016). Dietary extra virgin olive oil attenuates kidney injury in pristane-induced SLE model via activation of HO-1/Nrf-2 antioxidant pathway and suppression of JAK/STAT, NF-κB and MAPK activation. The Journal of Nutritional Biochemistry, 27, 278–288.
- Boero, R., Pignataro, A., & Quarello, F. (2002). Salt intake and kidney disease. Journal of Nephrology, 15(3), 225–229.
- Chapter 4 – water. (2005). In Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. The National Academies Press.
- Chauveau, P., Aparicio, M., Bellizzi, V., Campbell, K., Hong, X., Johansson, L., Kolko, A., … & European Renal Nutrition (ERN) Working Group of the European Renal Association–European Dialysis Transplant Association (ERA-EDTA). (2018). Mediterranean diet as the diet of choice for patients with chronic kidney disease. Nephrology, Dialysis, Transplantation: Official Publication of the European Dialysis and Transplant Association – European Renal Association, 33(5), 725–735.
- Chou, H.-I., Chen, K.-S., Wang, H.-C., & Lee, W.-M. (2016). Effects of cranberry extract on prevention of urinary tract infection in dogs and on adhesion of Escherichia coli to Madin-Darby canine kidney cells. American Journal of Veterinary Research, 77(4), 421–427.
- Gutiérrez, O. M., Muntner, P., Rizk, D. V., McClellan, W. M., Warnock, D. G., Newby, P. K., & Judd, S. E. (2014). Dietary patterns and risk of death and progression to ESRD in individuals with CKD: A cohort study. American Journal of Kidney Diseases: The Official Journal of the National Kidney Foundation, 64(2), 204–213.
- Hoogeveen, E. K., Geleijnse, J. M., Kromhout, D., Stijnen, T., Gemen, E. F., Kusters, R., & Giltay, E. J. (2014). Effect of omega-3 fatty acids on kidney function after myocardial infarction: The Alpha Omega trial. Clinical Journal of the American Society of Nephrology: CJASN, 9(10), 1676–1683.
- Hu, J., Liu, Z., & Zhang, H. (2017). Omega-3 fatty acid supplementation as an adjunctive therapy in the treatment of chronic kidney disease: A meta-analysis. Clinics , 72(1), 58–64.
- Nair, A. R., Masson, G. S., Ebenezer, P. J., Del Piero, F., & Francis, J. (2014). Role of TLR4 in lipopolysaccharide-induced acute kidney injury: Protection by blueberry. Free Radical Biology & Medicine, 71, 16–25.
- National Kidney Foundation. (n.d.). Top 5 jobs kidneys do. https://www.kidney.org/kidneydisease/top-5-jobs-kidneys-do
- National Kidney Foundation. (2015). 6 tips to be “water wise” for healthy kidneys. https://www.kidney.org/content/6-tips-be-water-wise-healthy-kidneys
- National Kidney Foundation. (2020). Potassium and your CKD diet. https://www.kidney.org/atoz/content/potassium
- NIH. (2021). Potassium – fact sheet for health professionals. https://ods.od.nih.gov/factsheets/Potassium-HealthProfessional/
- Nimalaratne, C., & Wu, J. (2015). Hen egg as an antioxidant food commodity: A review. Nutrients, 7(10), 8274–8293.
- Panahi, Y., Dashti-Khavidaki, S., Farnood, F., Noshad, H., Lotfi, M., & Gharekhani, A. (2016). Therapeutic effects of omega-3 fatty acids on chronic kidney disease-associated pruritus: A literature review. Advanced Pharmaceutical Bulletin, 6(4), 509–514.
- Rebholz, C. M., Crews, D. C., Grams, M. E., Steffen, L. M., Levey, A. S., Miller, E. R., 3rd, Appel, L. J., & Coresh, J. (2016). DASH (Dietary Approaches to Stop Hypertension) diet and risk of subsequent kidney disease. American Journal of Kidney Diseases: The Official Journal of the National Kidney Foundation, 68(6), 853–861.
- Rodrigues Neto Angéloco, L., Arces de Souza, G. C., Almeida Romão, E., & Garcia Chiarello, P. (2018). Alkaline diet and metabolic acidosis: Practical approaches to the nutritional management of chronic kidney disease. Journal of Renal Nutrition: The Official Journal of the Council on Renal Nutrition of the National Kidney Foundation, 28(3), 215–220.
- Samout, N., Bouzenna, H., Dhibi, S., Ncib, S., ElFeki, A., & Hfaiedh, N. (2016). Therapeutic effect of apple pectin in obese rats. Biomedicine & Pharmacotherapy, 83, 1233–1238.
- Scott, A. M., Clark, J., Mar, C. D., & Glasziou, P. (2020). Increased fluid intake to prevent urinary tract infections: Systematic review and meta-analysis. The British Journal of General Practice: The Journal of the Royal College of General Practitioners, 70(692), e200–e207.
- Shankar, M., Narasimhappa, S., & N S, M. (2021). Urinary tract infection in chronic kidney disease population: A clinical observational study. Cureus, 13(1), e12486.
- Spim, S. R. V., de Oliveira, B. G. C. C., Leite, F. G., Gerenutti, M., & Grotto, D. (2017). Effects of Lentinula edodes consumption on biochemical, hematologic and oxidative stress parameters in rats receiving high-fat diet. European Journal of Nutrition, 56(7), 2255–2264.
- Szaefer, H., Krajka-Kuźniak, V., Bartoszek, A., & Baer-Dubowska, W. (2012). Modulation of carcinogen metabolizing cytochromes P450 in rat liver and kidney by cabbage and sauerkraut juices: comparison with the effects of indole-3-carbinol and phenethyl isothiocyanate. Phytotherapy Research: PTR, 26(8), 1148–1155.
- Tack, I. (2010). Effects of water consumption on kidney function and excretion. Nutrition Today, 45(6), S37.
- Tallman, D. A., Sahathevan, S., Karupaiah, T., & Khosla, P. (2018). Egg intake in chronic kidney disease. Nutrients, 10(12).
- U.S. Department of Agriculture. (2019). FoodData Central – cabbage. https://fdc.nal.usda.gov/fdc-app.html#/food-details/169975/nutrients
- U.S. Department of Health and Human Services. (2020). Eat less sodium: Quick tips. https://health.gov/myhealthfinder/topics/health-conditions/heart-health/eat-less-sodium-quick-tips
- USGS. (n.d.). The water in you: Water and the human body. Retrieved October 14, 2021, from https://www.usgs.gov/special-topic/water-science-school/science/water-you-water-and-human-body?qt-science_center_objects=0
- Xu, C., Zhang, C., Wang, X.-L., Liu, T.-Z., Zeng, X.-T., Li, S., & Duan, X.-W. (2015). Self-fluid management in prevention of kidney stones: A PRISMA-compliant systematic review and dose-response meta-analysis of observational studies. Medicine, 94(27), e1042.
- Zheng, G.-H., Shan, Q., Mu, J.-J., Wang, Y.-J., Zhang, Z.-F., Fan, S.-H., Hu, B., … & Zheng, Y.-L. (2019). Purple sweet potato color attenuates kidney damage by blocking VEGFR2/ROS/NLRP3 signaling in high-fat diet-treated mice. Oxidative Medicine and Cellular Longevity, 2019, 5189819.