Roasted eggplant with herbs for a low-sodium diet

Potassium is a vital mineral responsible for a number of body functions. It helps regulate your blood pressure, maintain fluid and electrolyte balance, and it supports muscle contractions.

When you have chronic kidney disease (CKD), your kidneys have a reduced capacity keep your blood potassium at healthy levels. Excess potassium in the blood can have negative effects in your health.

Through a balanced diet and regular checkups, you can keep your potassium levels within a normal range without straining your kidneys. Read on to learn more.

What’s the Connection Between CKD and High Potassium Levels?

The central role of the kidneys is to filter out excess fluids and wastes from your blood. Well-functioning kidneys can clean 120 to 150 quarts of blood per day, disposing of waste materials to 1 to 2 quarts of urine.

This mechanism is what prevents the buildup of waste in your body. Besides their filtering capabilities, kidneys also ensure the balance of sodium, potassium, and phosphate amounts in the blood.

All these regulatory roles are restricted when CKD comes into the picture. People with declining kidney function cannot regulate potassium, making them prone to an alarming increase of potassium content in their blood.

This medical condition is called hyperkalemia. Dangerously high levels of potassium in the blood manifest through the following symptoms:

  • Numbness
  • Tiredness
  • Irregular heartbeat (in worse cases, this could eventually lead to a heart attack)
  • Nausea
  • Muscle pains or cramps
  • Poor appetite
  • Difficulty breathing

In addition to loss of kidney function, a surge in potassium levels can be caused by:

  • High-potassium diet - Potassium enters the body through the food and drinks you consume. Bananas, cantaloupe, potatoes, orange juice, and honeydew melon are some of the foods that are high in potassium. Using salt substitutes in food is also a contributing factor.

  • Certain medications - Drugs like ACE inhibitors and some diuretics can prevent the kidneys from getting rid of excess potassium and cause a spike in potassium levels.
  • Uncontrolled diabetes - People with diabetes and diminished kidney function often have a difficulty excreting potassium into the urine. 

If you’re experiencing the symptoms of hyperkalemia, call your doctor immediately. Hyperkalemia is a serious condition which requires urgent medical care.

How Can I Know My Potassium Levels?

Urine test for potassium levels

Your doctor may recommend a potassium test if they suspect you have an electrolyte imbalance or if you’re showing symptoms of hyperkalemia.

A simple blood test is done to determine the level of potassium in your blood. You should be able to keep track of this if you undergo routine blood tests. For a few hours, you may need to fast or discontinue any medications that could affect your results prior to the test.

Another way to check your potassium levels is through a urine test wherein you will be asked to provide a sample of your urine. The collected sample will be sent to a lab for testing.

A regular physical exam is also important in evaluating your condition. Your doctor will ask you about your medical history, medication, and diet to identify the cause of your hyperkalemia and to create your treatment plan.

What is a Safe Blood Potassium Level?

Every person has unique nutritional requirements. But according to the American Kidney Fund, the dietary potassium intake recommended for people with mild to moderate CKD is 4.7 g (4,700 mg) per day. Those with advanced stage CKD and nearing dialysis must limit their potassium intake to 3 g (3,000 mg) per day or less.

Your monthly level of potassium is measured in millimoles per liter of blood (mmol/L). The results are usually categorized in 3 levels:

  1. Safe zone: 3.5 to 5.0 mmol/L
  2. Caution zone: 5.1 to 6.0 mmol/L
  3. Danger zone: 6.0 mmol/L or higher

Note that these ranges only serve as a guide. Actual ranges can vary from doctor to doctor and laboratory to laboratory. No matter the range used, you’ll want to stay within the baseline range or the safe zone.

It’s crucial to work with your doctor and dietitian in determining your daily potassium intake and to ensure you’re getting adequate nutrition. How much potassium you should consume depends on factors like your age, gender, and existing health conditions.

How Does Diet Play a Role in Potassium Regulation?

Making dietary changes is essential in preventing potassium buildup. Keep in mind that potassium is almost in every food you could think of. They’re also in many fruits and vegetables.

You must know which foods are high in potassium and which ones are low. It also helps to be meticulous in reading Nutrition Facts labels. Check the ‘% Daily Value (DV)’ column to know the specific amount of nutrients per serving of a product. A potassium content of more than 5% DV is considered high.

Eating right and managing what you eat is the safest approach in controlling your potassium for the long term. 

What Foods Should I Eat and Avoid?

For people with kidney disease, any food that contains 250 mg (or more) of potassium per serving is classified as a high potassium food.

Below are some high-potassium foods you need to limit or avoid:

Meats

  • Red meat
  • Fish
  • Chicken
  • Turkey

Fruits

  • Bananas
  • Avocados
  • Cantaloupe
  • Mangos
  • Kiwi
  • Oranges
  • Papaya
  • Prunes
  • Dried apricots
  • Raisins

Vegetables

  • Dried beans and peas
  • Potatoes (regular and sweet)
  • Tomatoes and tomato sauce
  • Brussel sprouts
  • Spinach

Beverages

  • Coffee
  • Juices and smoothies
  • Beer
  • Wine/champagne

Dairy

  • Milk
  • Ice cream
  • Yogurt

Seasonings, spreads, and sauces

  • Tomato ketchup and puree
  • Salt substitute
  • Peanut butter
  • Chocolate spread

On the other hand, low-potassium foods contain not more than 100 mg of potassium per serving. Your dietitian may recommend that you eat these foods if you have too much potassium in your blood:

Fruits

  • Apples
  • Berries (blueberries and strawberries)
  • Grapes
  • Pineapple
  • Cranberries and cranberry juice
  • Watermelon

Vegetables

  • Broccoli
  • Cauliflower
  • Cabbage
  • Eggplant
  • Green beans
  • Lettuce
  • Onion
  • Squash

Beverages

  • Water
  • Tea
  • Lemonade
  • Ginger beer
  • Tonic water or soda water

Dairy alternatives

  • Rice milk
  • Almond milk
  • Cashew milk
  • Soy milk

Low-potassium seasoning and flavoring alternatives

  • All herbs and spices
  • Pepper
  • Garlic
  • Applesauce
  • Honey

Others 

  • Egg whites
  • White rice
  • White pasta
  • White bread

Are There Cooking Methods That Reduce Potassium in Foods?

Leaching potatoes to make reduce potassium content

Along with consuming low-potassium food and drinks, the following cooking methods can also help lower the potassium content in your dishes:

1. Leach tuberous vegetables - Leaching tuberous vegetables like carrots, potatoes, and sweet potatoes reduces their potassium by 25 to 50%. 

Remember that the method of leaching only pulls out certain amounts of potassium from the vegetable and doesn’t remove it entirely. You still need to limit your portions of leached vegetables.

To leach, rinse, peel, cut them into thin slices, then soak them in warm water for at least 2 hours. 

After such time, re-rinse the veggies in water before cooking them. Boil vegetables in large amounts of water. If you have 1 cup of diced potatoes, boil them in 5 cups of water.

2. Pre-cook veggies before using them - Avoid throwing in raw carrots, potatoes, peas, and other high-potassium vegetables into soups, stews, or sauces. Cook fresh or frozen vegetables first before using them. 

Make sure to drain off the liquid in which you cooked the vegetables, don’t add them in the dish. After doing so, rinse them under cool running water to reduce as much potassium as possible.

3. Use herbs and spices instead of low-sodium seasonings - People with kidney disease and hypertension should avoid low-sodium products (e.g. cheese, milk, and baking powder) as well as salt substitutes as these contain potassium chloride in place of sodium chloride.

When on a low-potassium diet, use natural herbs, spices, lime, or lemon juice to add flavor to your food. Some flavor enhancers and condiments have low potassium content, but they tend to have lots of sodium.

As a rule of thumb, avoid using any seasoning or low-sodium products until you’ve consulted with your doctor.

4. Watch your intake of whole grains - People with declining kidney function must limit their consumption of whole grains that are high in potassium and phosphorus including brown rice, oats, quinoa, amaranth, and millet.

Go for low-potassium whole grain varieties like barley, buckwheat, white rice, and wild rice. Skip on breads and cereals that contain bran, as they have high levels of potassium.

What Are Some Low-Potassium Recipes You Can Suggest?

Ease your way into a low-potassium diet with these simple and dietitian-approved recipes (click on each recipes to see their ingredients, nutrient values, and cooking directions):

As always, before trying out these recipes, talk to your dietitian first to know how much you’re allowed to eat and if these foods are aligned with your diet plan.

Additional Resources on Healthy Dieting for People with CKD

Information stated here is not meant to replace professional advice from your doctor and dietitian. Your healthcare provider remains to be the ultimate source of information regarding your diet and overall health.

If you want to expand your knowledge on renal dieting and other related topics, check out these helpful articles by RenalTracker: