Key Nutrition Considerations for Kidney Disease Diet

The nutritional knowledge and tips you need to take care of your kidneys if they’re in trouble 

Rumour has it that there are so many things you can’t or shouldn’t eat if your kidneys aren’t functioning well or if you have kidney disease. From a Registered Dietitian’s perspective, I have to admit that, among many chronic conditions and diseases, there seem to be more links between nutrition and kidney health. However, this does not mean that people with kidney diseases can’t eat a healthy, balanced diet with a variety of foods and still enjoy eating. 

If you are confused about all the information you have heard about healthy eating for kidney health or a kidney disease diet, you are in the right place. This blog aims to provide you with the basic nutritional knowledge and tips to help you clear up the mist and light up your path.

What do kidneys do? 

Informally known as one of our “detox organs,” kidneys have the duty of removing solutes, regulating fluids and excreting metabolic wastes and drugs. Other functions of the kidney include regulation of blood pressure as well as acid-base balance, activation of vitamin D, and some important endocrine functions, such as hormone secretion. 

Although most people have two kidneys, there are circumstances where people can live perfectly fine with only one kidney, whether they only had one kidney at birth or lost one later on in their life for whatever reason. In other words, you may still have normal kidney functions if at least one of your two kidneys is working. 

However, just like any other organ, it is reasonable to expect our kidney functions to decline as we age. A common misconception that I have noted in my practice, especially when supporting people with a new diagnosis of chronic kidney disease, is the desire to bring their kidney functions back to normal. This unrealistic goal can cause a lot of mental stress, especially after they have tried everything, so stay tuned for the realistic things that we can do to help and make a difference for our kidneys. 

What are some common types of kidney disease? 

In my practice, there are three types of kidney diseases I’ve seen the most often: acute kidney injury, chronic kidney disease and kidney stones.  

• Acute Kidney Injury (AKI) refers to a sudden decline of kidney function which can have many causes, such as physical injuries of the kidney. Treatment of AKI is usually done in the hospital, where strict nutritional interventions may be warranted for the time being. However, with proper timely treatment, many people do recover fully from AKI and will resume their previous kidney functions. 

• Chronic Kidney Disease (CKD), on the other hand, is an irreversible condition categorized by the gradual loss of kidney function. CKD can be divided into five stages, depending on the remaining function of the kidney. Early detection and proper management both play an important role in delaying disease progression and preventing kidney failure. 

• Kidney stones are hard crystals made in the kidney from various wastes in the urine. Calcium oxalate is the most common form among all types of kidney stones. Varied in size, kidney stones may be flushed out of the body in the urine or may stay in the kidney and cause symptoms, such as pain and blood in the urine. 

Kidney Disease Diet and How Nutrition and Food Impacts Your Kidneys

Will the food I eat impact my kidney functions? The answer is yes. There are a few nutrients that are closely involved in how our kidneys function. 

1. Protein Management

Protein is one of the essential nutrients we need on a daily basis. Our body relies on the protein for muscle building, cell repair, immune system, wound healing and so on. 

Consuming excessive protein may cause additional stress to our kidneys, especially when their functions are already impaired. This is because our kidneys are in charge of removing byproducts/wastes from protein. However, because of all the above reasons we need protein for, it is NOT true that the less protein we eat, the better it is for our kidneys.  

Many people with chronic kidney disease I worked with in the past would develop some level of reluctance or even a fear of eating protein. Depending on the type and stage of your kidney disease, as well as your treatment method (e.g. dialysis), your protein requirement may be very different from others. 

It is recommended you consult with a Registered Dietitian if you are wondering whether you are eating enough or too much protein. 

2. Balancing Sodium and Potassium 

The balance of sodium and potassium in the body plays a key role in fluid regulation – one of the essential functions of our kidneys. When our kidneys are not functioning well, they may require additional attention from us to share some of their workload, such as monitoring and/or modification of our food consumption. Again, the recommendation needs to be individualized and may also change over time. 

3. Boost Phosphorus and Calcium

Phosphorus and calcium are two other minerals that work together to keep your bones healthy. Impaired kidney functions may cause your blood phosphorus level to go up, causing calcium to be kicked out of the bone over time, which can lead to brittle and easy to break bones. In addition, inadequate calcium consumption may also increase the risk of calcium oxalate formation, the most common type of kidney stones. 

4. Drinking Fluids 

Fluid is another area for consideration in kidney health. One common cause of kidney stones is the lack of fluid that helps flush out wastes in the urine. On the other hand, drinking too much fluid may also become a concern when our kidneys cannot efficiently get rid of the excessive fluid, causing issues such as fluid retention/edema. 

Some people, especially those whose kidneys can barely function on their own, may be told by their doctor to limit their fluid intake. A Registered Dietitian can help you make sense of what your fluid restriction may look like in real life and support you to tackle some practical challenges. 

What else should I pay attention to for a kidney disease diet? 

Aside from the specific nutritional considerations discussed above, an overall healthy eating pattern and lifestyle is always the foundation of any disease management. Regular follow-ups with your doctor and other professionals, including bloodwork and management of co-existing conditions and diseases, such as diabetes and hypertension, often lead to better disease outcomes as well as quality of life. 

Not to forget about your mental health, especially if you just got diagnosed, that yes, kidney diseases can be quite a challenging condition to manage, and yes, you are allowed to feel angry, disappointed, frustrated, and anxious. 

Please don’t hesitate to reach out for support because this really isn’t your fault. It is not the end of the world as many people with chronic kidney diseases learn to manage their health well and can still live a long, happy life. So can you! 

References:

National Kidney Foundation

BC Renal