Potassium and Potatoes: How to Lower Potassium Content by Half!

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Potatoes are high in potassium, but they can be modified so that you limit the potassium you need to stay healthy. This article will discuss how to make low potassium potatoes for those following a low potassium renal diet.

Potassium in the Renal Diet

The low potassium renal diet, also known as the low K renal diet or low K diet, is designed for those with chronic kidney disease (CKD) in order to limit their dietary potassium intake.

The kidneys normally do most of our excreting work but when they lose function we end up retaining these minerals that are essential for our health.

Potassium also interacts with the medications used for chronic conditions like diabetes, hypertension, heart disease, arthritis, and more by enhancing their effects or blocking them altogether.

This makes eating low potassium potatoes important to low potassium renal dieters.

Health Benefits of Potassium

Potassium is a mineral that helps your body maintain fluid and electrolyte balance.

This means potassium can help with

  • low blood pressure
  • high blood pressure
  • heart problems
  • kidney stones from low urine output or dehydration
  • muscle weakness/cramping (including leg cramps during pregnancy)
  • anxiety/nervousness

Potential Problems with Potassium

In some cases of chronic kidney disease, potassium may not be filtered enough. This can lead to a collection in the blood.

Too much potassium can cause;

  • Fatigue
  • Weakness
  • Numbness or tingling
  • Nausea
  • Vomiting
  • Chest pain
  • Irregular heartbeat or pulse
  • Low pulse
  • Paralysis

In serious cases, untreated high potassium levels can cause cardiac arrest. But not everyone will experience these issues, nor even have concerns with potassium to start.

This is why not everyone with kidney disease and on a renal diet needs to limit potassium. But in some cases, it may be incredibly important.

What qualifies as low potassium?

For food to qualify as low potassium, it needs to have less than 200mg potassium per serving to be considered low potassium.

This low level is important with regards to the renal diet because many people are on a low potassium or even low protein diet when they suffer from kidney disease.

Click here to read more about the low potassium diet.

Nutrition Profile of Potatoes

Potatoes are actually a very nutritious food, despite what some say. They are a good source of fiber, potassium, vitamin C, vitamin B6, and magnesium.

One medium white potato provides:

  • 159 calories
  • 13 milligrams sodium
  • 941 milligrams potassium
  • 37 grams carbohydrate
  • 4 grams fiber
  • 4 grams protein
  • 130 milligrams phosphorus
  • 70% DV vitamin C
  • 30% DV vitamin B6
  • 12% DV magnesium
  • 9% iron
Kidney Friendly Food Focus: Potato

Serving Size: 1 medium white potato (173g, baked)

Calories: 159 kcals
Protein: 4 g
Potassium: 941 mg
Phosphorus:  130 mg
Fiber:  4 g
Benefits: 
Very versatile! 
Good source of Vitamin C and Fiber

Ways to Use:
Baked, mashed, boiled, roasted... there are so many ways to enjoy potatoes! 
PRO TIP: Double boil to reduce potassium by ~50%!

While the phosphorus content seems high, it’s important to remember this is naturally occurring, organic phosphorus. This makes it poorly absorbed, as little as 30% of the phosphorus.

If you’re concerned about phosphorus, check out our low phosphorus diet article.

Potatoes are low in protein and low fat which is good for the kidney patient, but they do contain carbohydrates that can be high in phosphorus or low depending on how you cook them.

Potassium is also present so it’s important to understand what types of potatoes have more potassium than others if your goal is to keep to a low potassium diet.

Health Benefits of Potatoes

Potatoes provide many health benefits. They are low in fat and sodium which makes them suitable for those on low cholesterol, low salt diets too! They

Potatoes are also low-calorie and even gluten-free.

Potatoes provide the following health benefits:

  • Vitamin C to support your immune system
  • Vitamin B6 to keep you energized
  • Iron for blood health (think anemia!)

While many think of the carbohydrates in potatoes, it’s important to remember that potatoes are also a good source of fiber.

Fiber has been shown to help lower blood sugar spikes and support healthy blood pressure.

Fiber is mostly in the skin of potatoes, like other fruits and vegetables with edible skins.

Are potatoes high in potassium?

As noted above, potatoes are considered a high potassium food. However, with more than 4,000 varieties of potatoes, there are plenty of options – some lower in potassium than others.

It’s important to know that different varieties and preparation methods of potatoes will influence the amount of potassium in potatoes.

Type of PotatoPotassium in 100 grams raw
Idaho (Russet)295
Sweet Potato337
Red Bliss316
Yukon Gold404
Purple Viking448
White Rose319
Russian Banana381

As stated earlier, potatoes have a lot of potassium in them! This is why they should be limited in a low potassium renal diet.

This doesn’t mean you can never eat potatoes, but you should limit how much you eat and which types.

Can you soak potatoes to remove potassium?

This has been a long-time myth to lower potassium in potatoes and make them fit into a renal diet.

However, soaking even for up to 8 hours has not been shown to effectively and consistently lower potassium in potatoes.

Because it is not proven, it is important to limit potatoes if you are soaking them as a way to reduce potassium.

What about double boiling potatoes?

Double boiling is a great, proven way to make low potassium potatoes.

One study found that double-boiling potatoes could reduce potassium content by about 50%.

Potassium in Double Boiled Potatoes

The table below shows how much potassium was removed from potatoes with normal boiling and double boiling.

Type of Potatomg Potassium in Raw
(per 100 grams)
mg Potassium in Single Boil
(per 100 grams)
mg Potassium in Double Boil
(per 100 grams)
Idaho (Russet)295234170
Red Bliss316200194
Yukon Gold404314235
Purple Viking448283176
White Rose319249192
Russian Banana381258161

As you can see from the chart, the potatoes that are considered low potassium potatoes would be all the double-boiled potatoes except for Yukon Gold potatoes. Even after double boiling, these were above the 200 mg potassium threshold.

It’s important to follow the directions of how to double-boil potatoes to make them lower or low in potassium.

How to double boil potatoes

To double boil your potatoes, first wash them well. For the lowest potassium content, peel the skins off the potato. Wash again and then pat dry.

Dice into small pieces; less than 1″ cubes. Or for maximum potassium removal, use a mandoline or sharp knife to carefully slice potatoes into thin slices.

Add diced potatoes to a large pot and fill with fresh, cold water. Make sure potatoes are well-submerged by several inches of water.

Place on the stovetop on medium-high heat. Once boiling, allow to boil for 10-15 minutes.

Turn off heat, drain potatoes into a colander. Place potatoes back into the pot and add fresh water.

Bring water and potatoes to boil again over medium-high heat. Allow boiling again for 10-15 minutes.

Turn off heat and drain potatoes in the colander once more.

How to use double-boiled potatoes

Once you have double-boiled potatoes, you can cook them however you like.

If you diced the potatoes into cubes, they can be roasted in the oven or sauteed in a skillet.

Shredded potatoes are great for hash browns.

Of course, the sliced rounds can be used for scalloped potatoes.

Either shredded, diced or rounds can be used to make mashed potatoes.

Potassium in Mashed Potatoes

A common way to use double-boiled potatoes is with mashed potatoes. By using double-boiled potatoes, you’ll have less potassium in your mashed potato recipe compared to normal boiling.

In normal cooking, one cup of homemade mashed potatoes will have about 596 milligrams of potassium. This is with whole milk, which also has a lot of potassium.

You can learn about milk for the renal diet in our article here.

However, prepared mashed potatoes have even more potassium. Ready-made mashed potatoes can have almost 700 milligrams of potassium per one-cup serving.

So if you want to have mashed potatoes, double-boiling a homemade version is a great way to include it in your renal diet.

Low potassium alternatives to potatoes

There are some other foods that can be made to reduce the potassium content of your potato dishes even further.

The vegetables listed below can be prepared with double-boiled potatoes to further reduce the potassium content and make cooking easier.

Or you can simply prepare them while the potatoes are boiling and add in the final cooking step.

Cauliflower

Cauliflower is a very versatile vegetable and has been known to work well for a lower carbohydrate, low potassium potato substitute.

A 1/2 cup of boiled cauliflower has just 88 milligrams of potassium, but still gives you another gram of fiber.

Kidney Friendly Food Focus: Cauliflower

Serving Size: 1/2 cup boiled

Calories: 14 kcals
Protein: 1 g
Potassium: 88 mg
Phosphorus: 20 mg
Fiber: 1 g



Benefits: 
High in Vitamin C 
Good source of Folate

Ways to Use:
Sub for mashed potatoes
Use in rice recipes

For mashed potatoes, swap half the recipes’ potatoes for cauliflower in equal portions. That way you can still enjoy potatoes, but with significantly less potassium!

Carrots

If you have a recipe using sweet potatoes, try using carrots. You’ll get the golden yellow-orange color you want to keep, but also with less potassium.

One cooked carrot provides just 108 milligrams of potassium.

Kidney Friendly Food Focus: Carrot

Serving Size: 1 carrot (46 g)
Boiled

Calories: 16 kcals 
Protein: <1 g
Potassium: 108 mg
Phosphorus: 14 mg
Fiber: 1 g

Benefits: 
Contains Vitamin A
Has calcium and vitamin K - good for bone health!

So if you’re planning on making sweet potato pie, sweet potato casserole, or even simple mashed sweet potatoes, we encourage you to try this easy substitution!

Turnips

Turnips are another root vegetable that can be used with potatoes in either mashed or roasted potato recipes.

One cup of boiled turnip cubes provides 276 milligrams of potassium with 3 grams of fiber.

And yes, this is still considered high potassium. But when one cup of boiled potatoes has 512 milligrams of potassium, this swap still reduces the potassium content by about 50%.

Radishes

If you’re a fan of roasted red potatoes, you should definitely try adding in radishes next time.

A 100-gram (approximately 1/2 cup) serving of radishes has just 233 milligrams of potassium. In comparison, a 100-gram serving (about a 1/2 cup) of red potato has 455 milligrams of potassium.

Kidney Friendly Food Focus: Radish
Serving Size: 1/2 cup (raw slices) 

Calories: 9 kcals
Protein: 0 g 
Potassium: 135 mg
Phosphorus: 11 mg
Fiber: 1 g


Benefits: 
Contains in Vitamin A and fiber.
Packed with antioxidants. 


Ways to use:
Add to sandwiches for crunch and flavor
Use with hummus for a refreshing snack
Low Potassium Tip: Swap roasted red potatoes for roasted radishes. Add rosemary and garlic for a delicious side dish!

While raw radishes may seem spicy, when roasted the flavor mellows entirely and allows for whatever herbs and spices you use to come through. Try adding rosemary and garlic!

Canned Potatoes

You may be surprised to find that canned potatoes can be a lower potassium alternative to fresh potatoes.

A 1/2 cup of canned potatoes has approximately 260 milligrams of potassium without any extra boiling.

It’s good to know that many canned fruits, vegetables, beans and legumes can have lower potassium than their fresh counterparts. Be sure to check the label for low/no-added salt or sugar.

Summary: How to Include Potatoes in a Renal Diet

When it comes to low potassium potatoes, double boiling is a great way to help reduce the amount of potassium in your food.

Double boiling can reduce potassium content in potatoes by approximately 50%. However, it’s important to know that potassium content in types of potatoes will vary.

If potassium is a concern for your renal diet, try substituting it with other low potassium vegetables like carrots, cauliflower, radishes, or turnips.

Hopefully, you have found this article to help you see that potatoes can absolutely fit into a renal diet! The key is to understand portions and do what is best for your own renal diet.

Still need help with your renal diet and potassium needs?

If you’re still unsure about your own potassium needs, working privately with a dietitian is a great way to gain confidence and understanding with your renal diet.

You can learn more about our team of dietitians and apply to work with us by clicking here.

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