Diet is a key factor when it comes to preserving our kidneys’ health. In fact, almost all kidney diseases (KD) benefit from a change of diet as part of the treatment process.
The recommended dietary changes depend on other health conditions of the patient, the particular type of KD, and the stage (or progression level) of KD. However, there are several types of foods and nutrients that kidney dietitians may need to modify when preparing tailored renal diets for their patients. [1] Those include:
- Sodium (salt)
- Potassium-rich foods
- Phosphorus-rich foods
- Fluids
- Proteins
Specifically, dietary protein is a very controversial topic, as various types exist: animal and plant-based proteins, with high or low quality. And there are many common misconceptions about how protein consumption is related to the health of our kidneys.
This article will guide you through the relationship between kidneys and protein!
Let’s dive in!
Can high protein diet compromise kidney health?
A 2020 review paper suggests that a high protein diet (HPD) may lead to impaired glomerular filtration process (when the kidneys filter excess fluid and waste products from the blood into the urine). [2]
Due to a significant rise in the levels of amino acids and other waste products from protein metabolism, the arteries around the kidneys may dilate, causing hyperfiltration. This could lead to chronic kidney disease (CKD) or other kidney impairment.
The paper also emphasizes the fact that individuals with healthy kidneys are less likely to be affected by a HPD, but there are other individuals that might bear higher risk:
- People with diabetes
- People with a high Body Mass Index (BMI)
- Individuals with a solitary kidney
- Patients at early stages of CKD
High blood pressure can be a leading cause for CKD
According to the NIDDKD, increased blood pressure is the second leading cause of CKD development. [3] At the same time, hypertension is closely related to overconsumption of animal-based protein, especially red meat. [4]
In that sense, long term and uncontrolled hypertension may lead to increased intraglomerular pressure (pressure in the blood vessels around the kidney) in individuals who are at risk of kidney disease. [5] This may lead to dilation of blood vessels, filtration impairment, and further progression of KD.
Can plant-based protein consumption slow down kidney malfunction?
Several studies suggest that diets high in plant-based protein can be associated with a lower degree of kidney damage, compared to animal protein intake [6]
In that sense, vegetarian and plant-based diets may have beneficial effects on blood pressure and glucose, leading to improved health of the blood vessels. As a result, switching from animal to plant protein sources in your meals may limit KD progression and prevent secondary complications. [7]
Should you eat bananas if you have kidney disease? Find out the answer in our dedicated article!
Do all kidney patients need the same amount of protein?
Individuals need to consume different amounts and types of proteins in order to support their body functions and control their kidney health. The National Kidney Foundation gives some hints on how much protein to consume. [8]
- KD without dialysis: It can be beneficial to adopt a low or moderate protein diet, limit the consumption of red meat, and include more plant protein sources.
- Individuals on dialysis: Increased protein intake is important, as dialysis patients have higher protein needs. Dialysis damages important proteins from blood and gets rid of excess byproducts from protein metabolism. A low-protein diet can lead to malnutrition in people on dialysis
Conclusion
There is no single answer to the question, “Is dietary protein bad for your kidneys?” because there are many factors that we have to look into. Always follow the recommendations of your healthcare provider to prevent complications.
Disclaimer: This information is meant for educational purposes only. It is not intended to replace the counsel of a medical doctor.