For many people shifting toward low-carbohydrate diets—whether ketogenic, carnivore, or other variations—the topic of protein intake often sparks concern, especially regarding kidney health. A widespread belief persists that consuming too much protein can harm the kidneys, potentially causing kidney disease or worsening existing kidney conditions. But is this fear backed by scientific evidence, or is it simply a myth? Let’s explore what the latest insights, including those shared by Dr. Berry, reveal about protein and kidney health.
The Origin of the Protein-Kidney Myth
The idea that high protein consumption damages kidneys has been around for decades, but it largely stems from outdated and poorly conducted studies. Early research suggested that excess protein could increase the kidneys’ workload, leading to damage. However, these studies were limited in scope and failed to distinguish correlation from causation.
Modern science paints a different picture. High-quality, recent studies have consistently shown that healthy individuals, and even those with existing chronic kidney disease (CKD) in many cases, do not experience kidney damage from increased protein intake. Dr. Berry emphatically states, “Protein is not bad for your kidneys,” emphasizing that the myth lacks a foundation in credible research.
Understanding Kidney Function and Common Markers
When discussing kidney health, you might come across terms like BUN (blood urea nitrogen), creatinine levels, and glomerular filtration rate (GFR). These are common lab tests used to assess how well the kidneys are functioning.
-
BUN measures the amount of nitrogen in the blood that comes from urea, a waste product formed after the breakdown of protein. Importantly, an elevated BUN does not necessarily indicate kidney damage; often, it simply reflects higher protein intake.
-
Creatinine is a waste product from muscle metabolism. Elevated creatinine can indicate impaired kidney function.
-
GFR estimates how much blood the kidneys filter per minute. A low GFR often points to kidney problems.
It’s crucial to understand that a mere increase in BUN due to a high-protein diet is not a sign of kidney damage. True kidney impairment is better indicated by elevated creatinine and reduced GFR values.
What Does Damage the Kidneys?
If protein isn’t the culprit behind kidney disease, what is? Evidence suggests that the modern dietary landscape, rich in processed carbohydrates and sugars, plays a significant role in kidney damage. The rise in kidney disease prevalence parallels the increased consumption of high-carbohydrate processed foods over the past several decades, not high-protein diets.
This shift toward carb-heavy meals contributes to metabolic conditions such as diabetes and hypertension, which are well-established risk factors for CKD. Therefore, managing carbohydrates and overall metabolic health is more critical for kidney preservation than limiting protein intake in healthy individuals.
Protein in Context with Low-Carb Diets
Low-carb diets often naturally elevate protein consumption, alongside fat intake. Whether following a ketogenic protocol, carnivore diet, or other low-carb variations, many people consume more protein than their previous standard diet. According to Dr. Berry, this rise in protein intake has not resulted in kidney harm. In fact, many users report improved health markers on these diets.
Dr. Berry personally follows a carnivore approach with a balance of fat and protein (roughly equal grams) and reports excellent kidney function and overall well-being. This anecdotal evidence, combined with a large number of testimonials from others adopting similar diets, reinforces the safety of eating higher protein amounts for most people.
Debunking the Misconceptions
The bottom line is this:
- Protein does not inherently damage kidneys in healthy individuals.
- An elevated BUN due to high protein intake is normal and not a sign of kidney failure.
- True kidney disease, indicated by elevated creatinine or low GFR, is unrelated to protein consumption.
- High carbohydrate intake and metabolic diseases contribute far more to kidney damage than protein.
If someone warns you that “all that protein will kill your kidneys,” it’s likely they are repeating outdated or inaccurate information. Trusted health professionals and updated research confirm that protein, when consumed responsibly, is safe and essential for bodily health.
Conclusion
The myth that a high-protein diet leads to kidney disease is just that—a myth, unsupported by current scientific evidence. Instead, focusing on overall metabolic health, reducing excessive carbohydrate intake, and maintaining balanced nutrition is key to protecting kidney function. As research continues to evolve, it becomes clearer that protein is a valuable macronutrient, not a dangerous enemy to your kidneys.
For those embracing low-carb or ketogenic lifestyles, this should come as reassuring news: you can enjoy your protein-rich meals without undue fear of harming your kidneys. Always consult with your healthcare provider if you have existing kidney conditions before making dietary changes, but know that for many people, protein is not the foe it has been made out to be.
