Does a Ketogenic Diet Cause Kidney Stones?
I remember the first time I learned about the connection between a diet high in sugar and gout, kidney stones and heart disease. I was reading a book (I don’t remember which one) that was laying out the evidence that showed a clear link between sugar consumption and those diseases and it immediately peaked my interest because I didn’t know that gout was still a thing. I had only heard of old French monarchs having it and honestly didn’t know it was still around until just a few weeks before reading that book.
Just a few weeks prior to reading that, I learned that my son’s Father in Law had gout and occasional kidney stones and as I read that passage in the book, I thought about calling him and telling him what I read. I decided against it and figured I would bring it up the next time I saw him at church. Unfortunately, before I ever got a chance to say anything to him, he had a heart attack. He’s fine now but I have always felt bad I didn’t immediately make a call. I realize it wouldn’t have done much given how quickly it all happened but still, I should have said something.
Since then, probably the most common question I get about the ketogenic diet is whether or not it will cause kidney stones and there is definitely a connection but possibly not how you think. First let’s go over how kidney stones are formed.
How Kidney Stones are Formed
At one point in time it was thought that uric acid was produced solely from the breakdown of purines found in foods like liver, pork, mushrooms, anchovies, mackerel and dried beans which is why most patients that were susceptible to kidney stones or gout were put on a low purine diet. Unfortunately those diets didn’t work too well and almost always had to be supplemented with additional medications that controlled the formation of uric acid. As the Uric acid levels in the blood increased it would form small needle like crystals usually in the joints of the foot causing the painful disease Gout or as it was filtered out through the kidneys it would form kidney stones that would then need to be passed through the urinary track. If both of those things sound incredibly painful, you would be right.
The Role of Fructose in Kidney Stone Formation
It has only been in the last few years that we have discovered that a far greater cause of the formation of uric acid is excess consumption of fructose. Diets that are low in fructose and other sugars like the ketogenic diet have been shown to be far more capable of reducing uric acid levels below the 6.0 mM mark that prevents the formation of the crystals that cause gout and kidney stones. In fact Dr Adam Nally has said that one of the first medications he is able to take his patients off is their anti-uric acid medications as he sees a rapid drop in uric acid levels once his patients stop eating sugar, even if the patient also raises the amount of purine containing foods the consume like pork (bacon), liver and certain fish.
How Cheating on a Ketogenic Diet Increases Uric Acid
However, there is one huge caveat to all this. If you are already susceptible to these diseases, once you are on a ketogenic diet, you can’t cheat. Cheating is almost always a surefire way to rapidly up the amount of uric acid in your blood and begin to see those gout symptoms or start creating kidney stones. The most common stories I hear are usually right after a big Holiday and someone eats a lot of Halloween candy or Christmas cookies or after a weekend out on the lake where they have gotten dehydrated and had a few too many beers. Rapidly increasing the amount of fructose you consume in a very short amount of time like that will spike your uric acid levels and increase your risk of a flare up of gout symptoms or kidney stones.
How to Prevent Gout and Kidney Stones
The good news is this. If you have had gout or kidney stones in the past, there is a way to never suffer from those again without any medications. (Obviously you will want to consult with your doctor before stopping any medication) All you have to do is remove all the fructose from your diet and not only will you see your Uric acid levels fall but you will begin to enjoy all the other benefits of a sugar free diet like weight loss and more!