Potassium binders, your heart and your kidneys: What's the connection?

Potassium is a hot topic for people living with kidney disease and is a source of constant questions. Does this have too much potassium? Will it raise my potassium? What if I eat a smaller portion? How can I eat a healthy but lower potassium diet? 

Part of the confusion is caused by the fact that many foods that are high in potassium are also considered by experts, such as registered dietitians and doctors, to be the cornerstone of a healthy diet. Vegetables, fruits, beans, whole grains and lean proteins are naturally high in potassium, but provide many benefits, including helping to:  

• maintain a healthy weight
• keep blood sugar in the normal range 
• lower or keep cholesterol in the normal range 
• maintain a healthy blood pressure
• keep the gastrointestinal (GI or digestive) tract regular 

Potassium helps protect your overall health in other ways too, including your heart health. Time and time again, medical research shows that an eating pattern like the D.A.S.H. diet (Dietary Approaches to Stop Hypertension) or the Mediterranean diet, improves heart health, blood pressure, blood sugar and kidney health, and can potentially lead to a longer, better quality life. These eating patterns focus on vegetables, fruits, whole grains, beans and some lean protein including chicken, fish, eggs and dairy. 

Why would a kidney blog post be talking about heart health? Well, the kidneys and heart are interconnected and have a long and complicated relationship, but basically when your heart isn't working the way it should, it adds strain on your kidneys, which can lead to kidney disease. And vice versa: when your kidneys aren't working the way they should, it adds strain on your heart which can lead to heart disease. This is called cardio-renal syndrome. 

But why should you worry about heart health? If you have kidney disease, you are at a higher risk for heart disease. Advancements in medical care, including medicines such as Renin–angiotensin–aldosterone system inhibitors (RAAS inhibitors) help manage some of the most complex heart conditions (including high blood pressure) and can help slow the progression of kidney disease. However, it is important to note that RAAS inhibitors could also raise your potassium levels. 

These medicines may not be used as often in the kidney population because of the possible side effects that can cause high potassium (hyperkalemia). It is important to talk to your doctors about how you can best manage your potassium levels over time and if any of your medicines could affect your potassium levels. 

We know having high levels of blood potassium is serious, potentially life-threatening and should not be taken lightly. We also know that heart disease is just as serious. So, what should you do if you need a RAAS inhibitor for your heart health but need to keep your potassium low for your kidney disease? 

Luckily, there is a class of medicines to help control potassium levels called potassium binders. The current generation of potassium binders was approved by the Food and Drug Administration (FDA) in October 2015. A potassium binder works by sticking to the potassium in your body and preventing some of it from being taken into your bloodstream. This helps to keep potassium from building up in your blood. These potassium binders are a game changer. Because they do a very good job of lowering potassium, you can now take lifesaving heart medicines and eat the healthy foods that are higher in potassium without worrying as you once did about your potassium levels.(1)

But there is more good news! Studies about potassium are being published with some surprising findings. They are showing that:

• potassium from whole foods sources may not actually be increasing your blood potassium as much as we thought  
• potassium from vegetables, fruits, whole grains and beans are not absorbed as well as once believed 
• people with kidney disease who are not on dialysis and are following a lower potassium eating plan had a faster progression of their kidney disease as compared to people following an eating plan focused on foods higher in natural potassium, like the DASH diet or Mediterranean diet, and kept kidney function much longer.(2,3) 

If you are living with kidney disease and/or high potassium, it is important to make sure you are tracking your potassium levels and that you check with your health care team and dietitian about what eating plan will work best for you. Working with a registered dietitian may help you start to include foods that were once off limits. These vegetables, fruits, beans, whole grains and some lean proteins may be back on your menu as you work together as a team with your dietitian and health care team to do it safely. Bon appétit!

To learn more about managing high potassium, check out AKF's new hyperkalemia patient guidelines. Additional helpful resources on potassium and your kidneys can be found through our Beyond Bananas™ campaign found on AKF's Kidney Kitchen®. 

We are grateful to AstraZeneca for their support of all of this important content, including the Beyond Bananas campaign.

References: 

1. Chaitman, Martin et al. "Potassium-Binding Agents for the Clinical Management of Hyperkalemia." P & T : a peer-reviewed journal for formulary management vol. 41,1 (2016): 43-50.
2. Picard, Kelly, et al. "Dietary potassium intake and risk of chronic kidney disease progression in predialysis patients with chronic kidney disease: A systematic review." Advances in Nutrition, vol. 11, no. 4, July 2020, pp. 1002–1015, https://doi.org/10.1093/advances/nmaa027. 
3. Sumida, Keiichi, et al. "New insights into dietary approaches to potassium management in chronic kidney disease." Journal of Renal Nutrition, vol. 33, no. 6, Nov. 2023, https://doi.org/10.1053/j.jrn.2022.12.003. 
4. Yamazaki, Osamu, and Shigeru Shibata. "Another evidence that supports the continued use of RAS inhibitors in end-stage kidney diseases." Hypertension Research, vol. 47, no. 7, 24 Apr. 2024, pp. 1984–1986, https://doi.org/10.1038/s41440-024-01695-7. 
5. Rai, Nayanjot K., et al. "CKD progression risk and subsequent cause of death: A population-based Cohort Study." Kidney Medicine, vol. 5, no. 4, Apr. 2023, p. 100604, https://doi.org/10.1016/j.xkme.2023.100604.