Fact-checked by Dr. Anthony Gustin, DC, MS.
Written by Lorenz Mac
Whenever a non-traditional diet becomes mainstream, there’s skepticism about its real impact on health — and the ketogenic diet is no exception.
After all, it isn’t every day that you hear about a diet that encourages you to eat tasty, fatty cuts of meat.
Since dietary fats have been unfairly demonized for the past few decades, some people are worried that keto may affect your internal organs.
Specifically, there’s controversy about the keto-kidney connection.
So is the low carb, high fat lifestyle bad for your kidneys?
Read on to see the two sides of the debate.
In this article, we’re going to talk about:
More than 100,000 people are diagnosed with kidney failure in the United States[*]. This condition occurs when your kidneys can no longer properly eliminate waste.
Developing kidney problems is a common concern for people who are just starting a low carb diet, thanks to two common myths:
Myth #1: The Ketogenic Diet Causes Kidney Stones
Kidney stones form when a mass of crystals develop in your urinary tract. They are extremely painful and while the cause remains unknown, some people believe ketone production can exacerbate these symptoms.
The argument is that excessive high protein consumption requires your kidneys to work in overdrive and forces your body to excrete excess amounts of sodium, calcium and potassium. This loss of electrolytes may also lead to low blood pressure which may stress your kidneys even more.
However, research doesn’t seem to justify this argument.
One recent meta-analysis[*] that measured the impact of low carb diet on renal function taking into account 1000 people from nine randomised controlled trials found that:
“a low carbohydrate diet and the corresponding high-protein diet was not harmful for renal function in overweight and obese individuals without renal dysfunction.”
Furthermore, it concluded that a low carb diet may even improve renal function thanks to its weight loss effects.
Myth #2: Ketones Overwork Your Kidneys Due To Increased Urine Acidity
There’s a common misconception that nutritional ketosis can change the pH of your urine from neutral to acidic and therefore overwork your kidneys.
However, this only happens during ketoacidosis, not ketosis.
Ketoacidosis is a complication that results from dangerously high levels of ketones and blood sugar, most commonly in people with type I and II diabetes. This combination makes blood too acidic and negatively affects the liver and kidneys.
Ketoacidosis is most likely to occur in people with type 1 diabetes, who can’t produce any insulin.
Nutritional ketosis, on the other hand, is different because the level of ketones is in a normal range. When you’re in ketosis, you have more ketones in your blood than usual, but not enough to cause ketoacidosis.
The ketogenic diet is all about being in ketosis, not ketoacidosis.
Now that we’ve debunked those two myths, let’s look at why the ketogenic is actually beneficial for your kidneys.
Several skeptics have confused the masses about whether or not the ketogenic diet is healthy.
However, the truth is being in ketosis is a normal metabolic state. Our ancestors used nutritional ketosis for survival because they didn’t have access to carb-based meals three times a day like we do now.
Since we have evolved to use ketones for energy, going keto is not going to harm your kidneys.
In fact, studies are now proving that ketones are the preferred energy source over glucose. The heart and brain both run 25% more efficiently when your body is using primarily ketones for energy[*][*].
And again, the research confirms that a low carb diet, even one high in protein, doesn’t harm renal function in people without kidney issues. Those with normal kidney function can handle large amounts of protein without any issue.
Even if you have diabetes — which can put you at risk of kidney dysfunction –, keto is beneficial.
Diabetic nephropathy (DN) is a condition that occurs as a result of damaged kidneys due to diabetes. It is characterized damage to your glomeruli, the small units within the kidney where blood is filtered.
In short, diabetic nephropathy means your kidneys aren’t able to filter your blood properly[*].
Studies have shown that a properly formulated ketogenic diet can help reverse diabetic nephropathy[*].
Keto can improve this condition due to two main reasons:
#1: Glycemic Control
It’s hypothesized that more efficient glycemic control can help combat this diabetic kidney condition.
Ketone bodies like beta-hydroxybutyrate (BHB) help reduce the response to glucose and balance blood sugar, which can improve type II diabetes.
Having healthy blood glucose levels also reduces mortality rates in people with kidney disease.
In one study, researchers looked at 24,000 people with diabetes mellitus (DM) and assessed their HbA(1c) levels as an indicator of glycemic control. HbA(1c) is one of the most common markers of healthy blood glucose levels.
They found that people with diabetes and chronic kidney disease who had low HbA(1c) levels had increased mortality rates[*].
Another study looked at nephropathy in diabetic mice. They put the mice on a ketogenic diet and one week later, blood glucose levels were normalized. In the control group who was fed a high carbohydrate diet, several mice had died.
And just two months later, diabetic nephropathy was completely reversed in the mice who were on the ketogenic diet[*].
This shows that the ketogenic diet is highly effective for glycemic control and preventing early death due to kidney disease.
#2: Ketosis Positively Alters Genetic Expression in Your Kidneys
The previous study also found the gene expression of the mice had changed.
The researchers found the genes responsible for nephropathy — nephrin, ZO-1 and podocin — were reversed. This helped restore the mice’s kidneys back to healthy functioning[*].
This research provides compelling evidence that the ketogenic diet isn’t bad for your kidneys whatsoever. In fact, a low carb, high fat diet can actually improve chronic kidney disease, especially in people with diabetes.
Another perk of the keto diet for people with chronic kidney disease is heart health.
Chronic kidney disease directly increases the risk of cardiovascular disease (CVD), and cardiovascular disease increases the risk of CKD.
Research[*] has found that:
“There is mounting evidence that chronic kidney disease itself is a major contributor to severe cardiac damage and, conversely, that congestive heart failure is a major cause of progressive chronic kidney disease.”
That’s why a diet that can help improve both conditions is beneficial.
You just learned how keto can improve kidney disease, so now let’s look at how it reduces the risk of heart disease:
#1: Saturated Fat Is Beneficial, Not Harmful
For several years, the official dietary recommendations have blamed saturated fat for increased risk of heart disease and mortality.
That’s why many people think the heavy meat consumption on the ketogenic diet is bad for your heart and kidneys. We have been led to believe that red meat and other fatty meat products would damage our organs.
Research now proves this is false.
Studies have shown unprocessed meat doesn’t significantly increase the risk of cardiovascular disease (CVD) — only processed meat is harmful.
Processed meats — which we don’t recommend on keto– lead to a 70% increase in the risk of heart disease[*]. So as long as you stick to grass fed meat, your heart will be healthy.
#2: Keto Improves Cholesterol Profiles
All cholesterol is not created equal.
High-density lipoprotein (HDL) — also known as “good” cholesterol– is a health marker that many physicians look at to determine the health of their patients, especially those who have chronic kidney disease. An elevation in this type of cholesterol isn’t bad for your heart.
However, LDL (low-density lipoprotein)– aka bad cholesterol — is a major risk factor for heart disease.
Researchers are now finding that HDL cholesterol and saturated fat shouldn’t be to blame for heart disease.
On the other hand, LDL particle size is a more important biomarker to monitor.
One study found that lipid profiles did not predict mortality whereas smaller, LDL particles were linked to a 55% increase in the risk of mortality[*].
LDL particle size is affected by carbohydrate intake. Abundant carbohydrate consumption triggers the release of LDL[*].
Meanwhile, a low carb keto diet reduces LDL cholesterol — which improves kidney function.
The Relationship Between High Protein Diets and Chronic Kidney Disease
The previous studies show that high-protein diets do not have a negative impact in people who have normal kidney function.
Reduced protein consumption may only be beneficial in patients with advanced chronic kidney disease[*].
Following a low carbohydrate, adequate protein, high fat diet, can help prevent cardiovascular disease in people with chronic kidney disease.
Since ketosis and protein are not to blame for kidney problems, here’s what actually harms your kidneys:
The two main causes of chronic kidney disease are diabetes and high blood pressure[*]. As you just learned, a ketogenic diet can improve both of these risk factors.
Other risk factors include[*]:
- Old age
- Family history of kidney disease
- Cardiovascular disease
- Chronically high blood sugar levels
Weight control is also crucial for maintaining healthy kidney function. Obese people are more prone to chronic kidney disease, and obesity can be largely attributed to processed, high carb diets.
The Ketogenic Diet Protects Your Kidneys
The science is in: a ketogenic diet doesn’t exacerbate kidney problems, and in fact, it protects kidney health.
If you’re thinking of going keto but aren’t sure about the effect on your kidneys, research confirms a low carb, high protein diet won’t damage renal function, as long as you don’t have any pre-existing kidney conditions.
Any keto-ers experiencing kidney issues should look at the most common risk factors first: high blood pressure, diabetes, and obesity.
As long as you follow a proper keto diet plan, you should have no issues with kidney health.
Of course, always consult with your health professional first before starting a new diet, especially if you have kidney problems or have any other risk factor for kidney disease.