Potassium And Kidney Disease…Discussing Hyperkalemia, Diet & More

 AT-A-GLANCE

  • Plant-based diets are not associated with a higher risk of hyperkalemia in CKD patients    
  • Previously, the higher potassium content associated with plant-based diets was thought to be a risk factor for those suffering from impaired kidney function.    
  • Recent study published in Internal and Emergency Medicine revealed there was no significant link between eating a vegetarian diet and hyperkalemia.

What Is Hyperkalemia?

To understand what hyperkalemia is, it’s first fundamental to know what potassium is, since hyperkalemia is functionally just a term that refers to high levels of potassium. Potassium is a mineral that serves a variety of functions in the body, some of these include:

  • Supporting fluid balance
  • Moving waste
  • Maintaining effective nutrient absorption
  • Regulating proper heart beat rhythms
  • Balancing blood pressure
  • Sustaining normal muscle contractions.

Normal blood potassium levels typically range from 3.6 to 5.2 millimoles per liter (mmol/L). Having a blood potassium level higher than 5.3 is dangerous and when it reaches 6.0 this situation occurs, it’s referred to as ‘hyperkalemia.’

Potassium and Kidneys

Potassium and kidney disease are something of a balancing act with hyperkalemia frequently being found in CKD patients. The reason for this stems from impaired kidneys’ inability to effectively filter out excess potassium levels from diet, these then become toxins. It can also be exacerbated by some medications used to control CKD or concomitant conditions like diabetes and heart disease.

It’s crucial to monitor your potassium levels if you have chronic kidney disease and ensure that your serum potassium levels are within (or as close to) an acceptable, healthy range as possible. Hyperkalemia can quickly become a life-threatening situation if left untreated, resulting in cardiac arrhythmia episodes and even, death.

One of the best ways to manage hyperkalemia is through adopting a low-potassium diet. Depending on which drugs, if any, may be causing the increased potassium levels, your doctors may recommend decreasing the dosage of or discontinuing a specific drug. If neither of those strategies yield much benefit, the introduction of a potassium binder to your kidney care protocol may be necessary.

The Plant-Based Diet Connection to Potassium Levels & Kidney Disease

For many years, people struggling with chronic kidney disease have been told to limit high potassium foods and often times protein by adopting vegetarian diets or low-to-very-low protein diets. Protein levels need to be closely watched in people with CKD because excess protein, especially animal proteins can result in a condition known as proteinurea, or excessive protein in the urine which exhibits itself as extra-foamy urine. The other major components that need to be monitored, however, are phosphorous and potassium.

Plant-based diets are much lower in sulfur-containing amino acids and bioavailable phosphorous than meat-based diets. These results in not absorbing the phosphorus from plant based foods. 

Unfortunately, some vegetables do happen to have a very high potassium content which is why reading food labels is always strongly advised, especially for people on low potassium kidney disease diets.

Although plant-derived potassium can be beneficial, with their alkalizing properties reducing metabolic acidosis, the recommendations from nephrologists tend to cap potassium intake levels to 2000-3000 mg/d, which is far lower than the standard guideline of 4700 mg/d. This is definitely a case where “too much of a good thing” can go dramatically wrong if patients are not careful. This is why monitoring is so crucial.

Potassium And Kidney Disease Rate of Progression…What The Science Says

Although some people have suggested vegetable-rich diets can exacerbate the potassium levels in kidney disease patients and eventually lead to hyperkalemia, there is no solid evidence to substantiate this claim.

In a recent scientific study conducted by Adamasco Cupisti, MD and colleagues from Italy’s University of Pisa and reported in Internal and Emergency Medicine, plant-based low protein diets are still the safest choice for people trying to retain normal kidney function while in the stages of chronic kidney disease. The study concluded that vegetarian diets do not increase the risk factor for moderate to severe hyperkalemia development in CKD patients.

Out of the 219 nondialysis CKD renal nutrition clinic patients followed for the study, 26.1% had hyperkalemia with the vast majority exhibiting at least mild elevation in serum potassium. The vast majority had mildly elevated serum potassium levels with only 6 patients exhibiting moderate hyperkalemia (6.0 to 6.9 mEq/L). As eGFR decreased from 60 to less than 20 mL/min/1.73m2, hyperkalemia incidence spiked from 4.4% to 36.4%.

Serum potassium levels weren’t very different when it came to comparing those on plant-based diets versus those on animal-based diets with plant-based displaying 0.7 g/kg/day and animal-based displaying 0.6 g/kg/day. Both groups, including those with hyperkalemia and those not suffering from hyperkalemia used similar medicines, with as many as 85% of the group receiving renin-angiotensin-aldosterone system inhibitors or RAASi. None of those people discontinued their meds, although doses were adjusted.

They were all provided nutritional counseling, which more than likely helped them make better-informed choices about which vegetables were the most beneficial, while also being relatively low in potassium. The researchers found that, although hyperkalemia is a concern that warrants caution, hyperkalemia alone did not increase early mortality risk.

The research team expounded upon the rationale behind conducting the study, citing the numerous benefits of vegetarian and plant-based diets for the CKD patient population as a whole.

Some of these include prevention of acidosis as mentioned previously, prevention of constipation and gut dysbiosis. These benefits mitigate some of the risk factors erroneously associated with plant-based diets like hyperkalemia.

Although it is true some vegetables have high potassium levels, not all do. It’s really just a matter of knowing which ones to avoid and which ones to incorporate into your diet.

Potassium and Kidney Disease Plant-Based Diet Foods To Avoid

  • Bananas
  • Avocados
  • Raisins
  • Prunes and prune juice
  • Oranges and orange Juice
  • Tomatoes, tomato juice, and tomato sauce
  • Lentils
  • Spinach
  • Brussels sprouts
  • Split peas
  • Potatoes (regular and sweet)
  • Pumpkin
  • Dried apricots
  • Milk
  • Bran products
  • Low-sodium cheese
  • Nuts

Potassium and Kidney Disease Plant-Based Diet Foods To Incorporate

  • Berries, such as strawberries and blueberries
  • Apples
  • Grapefruit
  • Pineapple
  • Cranberries and cranberry juice
  • Cauliflower
  • Broccoli
  • Eggplant
  • Green beans
  • White rice
  • White pasta
  • White bread
  • Egg whites

Additionally, some of the things you can do to limit potassium include the way meals are prepared and eaten, some examples include boiling vegetables and moderating how many fruits you eat a day, limiting consumption to a maximum of 2 portions a day (portions are described as being the size of your hand). Opting for alternatives like rice/oat based cereals, rice milk, etc. 

It goes without saying, that monitoring your food is the best way to ensuring you stay safely within the appropriate potassium levels. You can learn more by reading our book on the Potassium, Protein, Phosphorous Content of many of the most common foods available at your local grocery store. You can find it here.

With the right diet and frequent monitoring of your potassium levels, you can not only keep hyperkalemia at bay, but live a healthier life while doing it.