Did you know that one medium banana contains about 425mg potassium  , which is about 10% of the total recommended daily intake of the mineral ?
This makes bananas one of the richest fruits in potassium (more than 200mg of potassium per portion), together with oranges, apricots, avocado, prunes, and dried fruits. But why is that important to mention?
For some people with advanced chronic kidney disease (CKD) it is important to limit the consumption of bananas (and other potassium-rich foods), as the mineral can build up in the body and result in increased risk of life-threatening health conditions.
But this is only one of the aspects when it comes to bananas and kidney health!
In this article, we will talk bananas, potassium, and kidney health! We will guide you through frequently asked questions about the effect of potassium on blood pressure, kidney stones, kidney disease, and dialysis.
Let’s get started!
Are bananas harmful to your kidneys?
Bananas are a great source of potassium, which is vital for supporting proper body and cell functions (including kidneys). The mineral is key for regulating fluid retention in the body (together with sodium,) as well as maintaining normal blood pressure levels.
In fact, potassium deficiency is closely associated with a rise in blood pressure levels, which can significantly increase the risk of kidney damage, heart disease, and stroke.  For that reason, potassium rich foods, including bananas, are an important part of the Dietary Approaches to Stop Hypertension eating pattern and can indirectly protect healthy kidneys from hypertension-related damage or impairment.
That being said, kidneys make sure you get balanced potassium levels in the blood by filtering and excreting excess amounts of the mineral out of the body. 
But what happens if your kidneys are damaged, their functions are impaired, such as in kidney disease? They cannot excrete excess potassium, which can lead to mineral buildup in the body for some people (associated with adverse effects.)
For most people, a diet high in potassium can help control blood pressure and prevent kidney disease. Even most people with kidney disease, a high potassium diet can help keep blood pressure in check and prevent further damage to the kidneys.
The right amount of potassium for you is dependent on your lab values. It is particularly important to ask your doctor, or ask to see a dietitian, to figure out how much potassium is right for you! It is important to remember that, even if you have to limit how much potassium you eat, fruits and vegetables are still a critical part of a healthy diet for kidneys. For many people, focusing on reducing potassium additives often found in meat, poultry and processed foods is most important to reduce potassium intake.
Find out more about the potassium as part of the renal diet in this article written by the kidney dietitian Melanie Betz.
Can you eat bananas with chronic kidney disease?
The typical renal diet (diet recommended for people with CKD- including those on dialysis) is different for everyone. If blood levels of potassium start to go up, a healthy renal diet excludes foods rich in potassium, like bananas, apricots, nuts, avocados, squash, and potatoes, because the kidneys are not effectively filtering and excreting excess amounts of the mineral.  This can result in hyperkalemia (buildup of potassium), the symptoms of which include  :
- Heart palpitations
- Chest pain
- Shortness of breath
It’s important to mention that while mild hyperkalemia may be asymptomatic, a significant buildup of potassium can result in life-threatening complications  :
- Cardiac arrest
Find a full list of potassium-rich and low foods provided by the National Kidney Foundation here.
Do bananas cause kidney stones?
Kidney stones are another story.
The National Kidney Foundation suggests that potassium citrate can be used for kidney stone prevention and treatment, as it may increase the urine citrate, as well as urine’s pH (making it less acidic). 
Besides, according to a 2016 study published in the Clinical Journal of the American Society of Nephrology, higher dietary potassium intake (eating potassium-rich foods like bananas) can be associated with 33-56% reduced risk of kidney stones formation.  The study results showed that potassium supply from food sources was associated with an increase in urine volume, reduced acidity, and lower saturation of calcium oxalate and uric acid in the urine.
Kidney health is not simple.
And while bananas (and other potassium-rich foods) can benefit and support your overall health, kidney functions, and reduce the risk of kidney stones formation, they may not be healthy for people with advanced CKD. For people with CKD who have high potassium levels, high potassium foods may result in severe health complications.
For that reason, monitoring your potassium blood levels and following the advice and dietary recommendations of your healthcare provider or clinical dietitian is crucial for supporting your kidney health.
Disclaimer: This information is meant for educational purposes only. It is not intended to replace the counsel of a medical doctor.