6 Kidney Disease Diet Myths

May 18, 2023

Many myths and misconceptions surround the world of kidney health and nutrition. Navigating through all the online information can be confusing and overwhelming, but we are here to help! 

Let’s explore the most common myths to provide you with the information you need to create a healthy, balanced diet plan that works.

Myth 1: There is only one kidney diet

Person smiling while making a pesto

Everyone is unique and that includes their dietary needs that depend on some of the following:

Working with your healthcare team and a kidney dietitian is the best way to create a diet plan that is right for you. Find a kidney dietitian near you

Creating the right diet for you can be confusing, but you may be eligible for programs that can help. 

Both services help you create a diet to help slow the progression of the disease. Call your insurance provider to see if you qualify for either program.

Sign the petition to expand access to Medical Nutrition Therapy.

Myth 2: Whole grains, nuts, seeds, and beans have too much phosphorus

Person eating almonds in the living room

Phosphorus is a mineral that builds strong bones and keeps other parts of the body healthy. However, if your kidneys can’t remove excess phosphorus from the blood, it can pull calcium from your bones or lead to dangerous calcium deposits in blood vessels, lungs, and heart. Those deposits can increase the risk of heart attacks and strokes if you don’t control phosphorus through diet or prescribed medications. 

Whole grains, nuts, seeds, and beans contain phosphorus, but that doesn’t mean you must cut them out of your diet. Your body only absorbs 50% of phosphorus from non-processed, plant-based foods! You absorb 80% to 100% of phosphorus from protein-rich foods like meat, fish, and dairy or processed foods with phosphorus additives. 

For example:

  • A half cup of whole grains contains around 200 mg of phosphorus, but your body will only absorb half of that, around 100 mg.
  • A half cup of whole milk crumbled feta cheese contains 328 mg of phosphorus, of which you’ll absorb 262 to 328 mg.

Phosphorus additives to keep an eye out for:

Sodium hexameta-phosphate

Dicalcium phosphate

Trisodium phosphate

Disodium phosphate

Sodium tripolyphosphate

Monosodium phosphate

Tetrasodium pyrophosphate

Phosphoric acid

Learn more about phosphorus.

Myth 3: People with kidney disease need a low-potassium diet

Person cheekily feeding their partner a carrot

Potassium is an essential mineral found in most foods that you cannot live without because it helps your nerves, muscles, and heart work properly. 

Contrary to the popular belief that everyone with kidney disease needs a low-potassium diet, people with kidney disease can be at risk of having too much or too little potassium.

  1. High potassium or hyperkalemia: Blood potassium levels are too high. You’ll need to eat less or low-potassium foods if you have high potassium. Your doctor may prescribe or adjust medications to help your body release extra potassium. Get a list of low-potassium fruits and vegetables.
  2. Low potassium or hypokalemia: Blood potassium levels are too low. You may need to eat more potassium or high-potassium foods if you have low potassium. Your doctor may prescribe or adjust medications to help you maintain potassium. Get a list of high-potassium foods.

Sudden or severe hyperkalemia and hypokalemia are life-threatening conditions requiring immediate medical care.

Learn more about potassium.

Myth 4: Kidney disease patients need to limit fruits and vegetables

Family happily eating dinner at the table

Even those who need to limit potassium need plenty of fruits and vegetables. Why? Like phosphorus, less potassium is absorbed from plant foods than from meat-based or overly-processed foods. The fiber content may also improve regularity, increase overall potassium excretion, and improve acidosis, a condition where body fluids contain too much acid. 

Having too much acid in the body can cause:

  • Kidney disease to progress more quickly
  • Increased bone loss or osteoporosis 
  • Muscle loss

Learn more about acidosis.

Myth 5: Salt substitutes are safer than salt

Person reading food label in store

Your body needs sodium to help nerves and muscles work correctly and help control fluid levels and blood pressure. However, too much sodium can negatively affect your health, especially if you have kidney disease. 

It can cause: 

  • High blood pressure 
  • Discomfort during dialysis
  • Fluid-build up around the heart and lungs

A natural reaction to this news would be to turn to a salt substitute, but many of these substitutes contain potassium chloride. This could be harmful, especially if you need to limit how much potassium you eat. Luckily, you don’t need to give up flavor when watching how much salt you eat. 

Try these instead: 

Fresh garlicRosemary
AllspiceBlack pepper
Fresh onionThyme
BasilLemon juice
Garlic powderSage
Curry powderVinegar
Onion powderGinger

If you choose low-sodium or salt-free seasoning blends, look at the label and choose one without potassium chloride. Check with your dietitian to see if it is okay to use.

Learn more about sodium.

Myth 6: People with kidney disease cannot go on a plant-based diet

Person happily eating a salad outside

In the past, plant-based foods were avoided because kidney doctors believed they had too much potassium and phosphorus but not enough protein. Now, we know that well-balanced plant-based diets created by kidney dietitians may prevent and slow the progression of chronic kidney disease, type 2 diabetes, high blood pressure, and heart disease.2

"If you're doing a good nutrient-dense plant-based diet with kidney disease, you may feel a lot better,” said kidney dietitian Jessianna Saville RD, CSR LDN.  “It's very doable, but if you feel nervous about it, work with your dietitian. They can help guide you.”

Learn more about plant-based diets

Sources

1 “Cheese, Feta, Whole Milk, Crumbled.” FoodData Central, USDA, https://fdc.nal.usda.gov/fdc-app.html#/food-details/2259796/nutrients.

2 Cooper, Matthew, et al. “Report of National Kidney Foundation Consensus Conference to Decrease Kidney Discards.” Clinical Transplantation, vol. 33, no. 1, 2018, https://doi.org/10.1111/ctr.13419.