Foods that protect your kidneys: the 7 with the strongest evidence
The short answer
Several foods on the usual kidney avoid list are the ones with the strongest evidence for protecting your kidneys. Counted down from 7 to 1, they are coffee, whole grains, nuts, soy, beans and lentils, what you season with in place of salt, and fruits and vegetables. In a five-year trial, fruits and vegetables matched a prescription pill on kidney function and beat it on blood pressure and LDL cholesterol. If your potassium runs high, change how you cook potatoes first. Then track two numbers, eGFR and UACR, to see whether it is working.
What we cover
The avoid list has it backwards. In more than 63,000 adults in Singapore followed for about 15 years, swapping one daily serving of red meat for soy or beans was linked to about half the risk of kidney failure. Primary source
7. Coffee. Across 12 studies with more than 500,000 people, coffee drinkers had a 14 percent lower risk of developing kidney disease, with a bigger gap at 2 or more cups a day, and an 18 percent lower risk of kidney failure. Keep it black or close to it. Primary source
6. Whole grains. In almost 15,000 American adults followed for a median of 24 years, eating mostly healthy plant foods, including whole grains, fruits, vegetables, nuts, beans, tea and coffee, came with a 14 percent lower risk of kidney disease. Plant foods like refined grains, potatoes, juice, sweets and sweetened drinks came with an 11 percent higher risk. On the label, the word whole should come first. Primary source
5. Nuts. In a 2025 review of 21 long-term studies, every 28 grams of nuts a day, about one small handful, came with a 21 percent lower risk of kidney disease. Primary source Much of the phosphorus in nuts, seeds, beans and whole grains is bound in phytate and absorbed less than the phosphate added to processed food, so check ingredient lists for words containing phos. Review
4. Soy. Across 18 randomized trials in 522 people with kidney disease, swapping animal protein for soy lowered the protein leaking into the urine by about 140 mg a day and LDL cholesterol by about 8 mg/dL. Try tofu in a stir-fry, edamame as a snack, or unsweetened soy milk in your oatmeal. Primary source
3. Beans and lentils. In the Singapore study, people who ate the most red meat had a 40 percent higher risk of kidney failure than those who ate the least. Primary source In the 2025 review, every 50 grams of beans a day, about a quarter to a third of a cup cooked, came with a 13 percent lower risk of kidney disease. Aim for a quarter to half a cup of cooked beans or lentils a day; no-salt-added canned beans are fine. Primary source
2. What you season with. In a two-week crossover trial of 20 adults with stage 3 or 4 kidney disease and high blood pressure, removing the extra salt lowered 24-hour blood pressure by 10/4 mm Hg and cut urine albumin about in half. Primary source The 2024 KDIGO guideline sets sodium under 2,000 mg a day. Guideline In 450 US adults, about 70 percent of sodium was added to food outside the home, and the salt shaker plus home cooking added about 10 percent. Primary source Skip potassium chloride salt substitutes if your potassium runs high, your kidney disease is advanced, or you take a potassium supplement or a potassium-sparing diuretic such as spironolactone. Review
The drink that didn't help. In 631 adults with stage 3 kidney disease, people coached to drink more water drank about 0.6 liters, roughly two and a half cups, extra a day for a year, and their kidney function fell by about the same amount as everyone else's. Drink to thirst and follow any fluid limit your kidney team gives you. Primary source
If your potassium runs high. In 245 people with kidney disease in Tokyo, neither fruit nor total potassium intake was tied to high potassium, but getting the most potassium from potatoes came with about 4 times the odds. Primary source Boiling potato cubes removed about half the potassium and boiling shredded potato about three quarters; soaking alone did not. If you're on dialysis, your kidney team sets your potassium limit. Primary source
1. Fruits and vegetables. In a five-year trial in Texas, 108 adults with kidney disease and acid buildup got fruits and vegetables, sodium bicarbonate pills or usual care. Kidney function (eGFR) fell about 19 points with usual care, 12 with the pills and 10 with fruits and vegetables, and the produce group ended with lower blood pressure and LDL than both other groups. Primary source A second five-year trial in 153 people with normal eGFR and protein in the urine found that 2 to 4 cups a day lowered acid buildup and urine albumin. Primary source
Your scoreboard and a day of eating. Check two numbers: eGFR, a blood test, where below 60 mL/min/1.73 m2 for three months or more means kidney disease, and UACR, a urine test, where under 30 mg/g is normal. Guideline The video's plan: oatmeal with strawberries and black coffee, lentil soup and a big salad, a tofu stir-fry with garlic and lemon and no salt shaker, and a handful of walnuts, then recheck both numbers in 90 days.
Timestamps
0:00 The foods on your avoid list
1:34 7. Coffee
2:19 6. Whole grains
3:36 5. Nuts
4:55 4. Soy
6:06 3. Beans and lentils
7:21 2. What you season with
9:17 The drink that didn't help
10:14 If your potassium runs high
11:42 1. Fruits and vegetables
13:53 Your scoreboard, and a day of eating
References
Lew QJ, et al. Red Meat Intake and Risk of ESRD. Journal of the American Society of Nephrology, 2017. https://pubmed.ncbi.nlm.nih.gov/27416946/
In 63,257 adults aged 45 to 74 in the Singapore Chinese Health Study, followed for a mean of 15.5 years, the highest quarter of red meat intake had a 40 percent higher risk of kidney failure than the lowest, and replacing one daily serving of red meat with soy and legumes was linked to a 50.4 percent lower risk. Evidence type: prospective cohort.
Kanbay M, et al. Effect of Coffee Consumption on Renal Outcome: A Systematic Review and Meta-Analysis of Clinical Studies. Journal of Renal Nutrition, 2021. https://pubmed.ncbi.nlm.nih.gov/32958376/
Across 12 studies with 505,841 people, coffee drinking was linked to a 14 percent lower risk of new kidney disease and an 18 percent lower risk of kidney failure. Evidence type: systematic review and meta-analysis of observational studies.
Kim H, et al. Plant-Based Diets and Incident CKD and Kidney Function. Clinical Journal of the American Society of Nephrology, 2019. https://pubmed.ncbi.nlm.nih.gov/31023928/
In 14,686 adults followed for a median of 24 years, the healthiest plant-based diets were linked to a 14 percent lower risk of kidney disease and the least healthy to an 11 percent higher risk. Evidence type: prospective cohort.
Sadeghi S, et al. Association between consumption of different food groups and risk of chronic kidney disease: a dose-response meta-analysis of prospective cohort studies. British Journal of Nutrition, 2025. https://pubmed.ncbi.nlm.nih.gov/40799007/
Across 21 prospective cohort studies, each 28 grams a day of nuts was linked to a 21 percent lower risk of kidney disease and each 50 grams a day of legumes to a 13 percent lower risk. Evidence type: dose-response meta-analysis of cohort studies.
Kalantar-Zadeh K, et al. Understanding sources of dietary phosphorus in the treatment of patients with chronic kidney disease. Clinical Journal of the American Society of Nephrology, 2010. https://pubmed.ncbi.nlm.nih.gov/20093346/
Phosphorus in plant foods is largely bound in phytate and only partly absorbed, while inorganic phosphate additives are absorbed almost completely. Evidence type: review.
Zhixiang Y, et al. The effects of soy protein and soy isoflavones intake on chronic kidney disease: a systematic review and meta-analysis. International Urology and Nephrology, 2025 (published online November 2024). https://pubmed.ncbi.nlm.nih.gov/39611889/
Across 18 randomized trials with 522 people with kidney disease, soy protein in place of animal protein lowered urine protein by about 140 mg a day and LDL cholesterol by about 8 mg/dL. Evidence type: meta-analysis of randomized trials.
McMahon EJ, et al. A randomized trial of dietary sodium restriction in CKD. Journal of the American Society of Nephrology, 2013. https://pubmed.ncbi.nlm.nih.gov/24204003/
In 20 adults with stage 3 or 4 kidney disease and high blood pressure, two weeks of low salt lowered 24-hour blood pressure by 10/4 mm Hg and median urine albumin from 291 to 143 mg a day. Evidence type: randomized, double-blind crossover trial.
Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International, 2024. https://pubmed.ncbi.nlm.nih.gov/38490803/
Recommends sodium under 2 grams a day in kidney disease, a diet with more plant-based foods, and testing both GFR and urine albumin. Evidence type: clinical practice guideline.
Harnack LJ, et al. Sources of Sodium in US Adults From 3 Geographic Regions. Circulation, 2017. https://pubmed.ncbi.nlm.nih.gov/28483828/
In 450 adults in 3 US regions, 70.9 percent of sodium was added to food outside the home, against 5.6 percent in home cooking and 4.9 percent at the table. Evidence type: observational study.
Goraya N, et al. Fruit and Vegetable Treatment of Chronic Kidney Disease-Related Metabolic Acidosis Reduces Cardiovascular Risk Better than Sodium Bicarbonate. American Journal of Nephrology, 2019. https://pubmed.ncbi.nlm.nih.gov/30995657/
In 108 adults with kidney disease and metabolic acidosis followed for 5 years, eGFR fell 18.8 points with usual care, 12.3 with sodium bicarbonate and 10.0 with fruits and vegetables, and systolic blood pressure and LDL were lowest with fruits and vegetables. Evidence type: randomized trial.
Goraya N, et al. Randomized Trial of Dietary Acid Reduction and Acid-Base Status of Patients With CKD and Normal Estimated GFR. Kidney International Reports, 2025 (published online November 2024). https://pubmed.ncbi.nlm.nih.gov/39990902/
In 153 adults with normal eGFR and protein in the urine followed for 5 years, fruits and vegetables (2 to 4 cups a day) or sodium bicarbonate lowered acid buildup and urine albumin compared with usual care. Evidence type: randomized trial.
Clark WF, et al. Effect of Coaching to Increase Water Intake on Kidney Function Decline in Adults With Chronic Kidney Disease: The CKD WIT Randomized Clinical Trial. JAMA, 2018. https://pubmed.ncbi.nlm.nih.gov/29801012/
In 631 adults with stage 3 kidney disease, coaching to drink more water raised urine output by about 0.6 liters a day but did not change the decline in eGFR over one year. Evidence type: randomized clinical trial.
Morimoto N, et al. Associations Between Dietary Potassium Intake From Different Food Sources and Hyperkalemia in Patients With Chronic Kidney Disease. Journal of Renal Nutrition, 2024. https://pubmed.ncbi.nlm.nih.gov/38621432/
In 245 people with kidney disease not on dialysis in Tokyo, total potassium intake was not linked to high potassium, while the highest potassium intake from potatoes came with 4.12 times the odds. Evidence type: observational study.
Bethke PC, Jansky SH. The effects of boiling and leaching on the content of potassium and other minerals in potatoes. Journal of Food Science, 2008. https://pubmed.ncbi.nlm.nih.gov/18576999/
Boiling potato cubes removed about half the potassium and boiling shredded potato about three quarters; soaking alone did not lower it. Evidence type: laboratory analysis of foods.
Xu X, et al. Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines. Hypertension, 2024. https://pubmed.ncbi.nlm.nih.gov/38284271/
A review of 32 hypertension and 14 kidney guidelines proposes potassium-enriched salt for people with high blood pressure unless they have advanced kidney disease or take a potassium supplement or a potassium-sparing diuretic. Evidence type: review of guidelines.
Greer RC, et al. Potassium-Enriched Salt Substitutes as a Means to Lower Blood Pressure: Benefits and Risks. Hypertension, 2020. https://pubmed.ncbi.nlm.nih.gov/31838902/
Reviews the blood pressure benefit of potassium-enriched salt substitutes and the risk of high potassium in people with kidney disease. Evidence type: review.
One study explained in plain language every week, with sources attached, plus the free kidney health guide: https://guides.selfprinciple.org/kidney
This content is for educational purposes only and is not medical advice. Always consult your healthcare provider for individual care. The views expressed are Dr. Hashmi's own and do not represent his employer.
If you're on dialysis or your potassium runs high, set your portions of fruit, vegetables, beans and nuts with your kidney team, and don't use potassium chloride salt substitutes.
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