Polycystic kidney disease or PKD is a common genetic disorder in which fluid-filled cysts grow in the kidneys. If left untreated, PKD can lead to reduced kidney function and eventually kidney failure. 
One of the ways to help treat PKD is making lifestyle and nutrition changes.
You may have heard about the new retrospective case series study by Thomas Weimbs and colleagues suggesting that the ketogenic diet is safe and potentially beneficial for individuals with autosomal dominant polycystic kidney disease (ADPKD), the most common form of PKD.
It’s actually the first study to gather real-life observations of ADPKD patients undertaking keto diet interventions (KDIs).
This article discusses keto and polycystic kidney disease, starting with a background on this condition. Then, we’ll dive into the latest research—how the study was done, the findings, and safety concerns to be aware of.
What Is Polycystic Kidney Disease (PKD)?
Polycystic Kidney Disease is an inherited kidney disorder characterized by fluid-filled cysts forming on one or both kidneys. These cysts continuously grow in size, which then compresses the nephrons (the filtering unit of your kidneys) and causes your kidneys to decline. 
More specifically, PKD affects important bodily functions, such as blood pressure and red blood cells production.
PKD affects more than half a million people in the United States. Furthermore, 90% of all PKD cases are autosomal dominant PKD (ADPKD), also called adult PKD, the most common form of PKD. 
If you have a parent with PKD, it means that you also have a chance of getting this condition.
What’s interesting about ADPKD is that adults can live with this condition for years without being aware of it. This is because ADPKD doesn’t cause obvious problems until the cysts grow up to a certain size.
Usually, adults seek help because they notice blood in their urine. Other signs and symptoms include: 
- Pain in the lower back, abdominal area, chest, and leg
- Decrease in appetite
- Weakness and fatigue
- Hypertension or high blood pressure
- Abnormal kidney enlargement with cysts (discovered upon ultrasound, CT scan, or MRI)
Glucose Strongly Affects the Growth of Renal Cysts
Research shows that polycystic kidney disease cysts rely on glucose as their fuel source. High glucose upregulates or increases the calcium-activated chloride channel ANO1, which has a huge impact on the enlargement of kidney cysts.  
Interestingly, many patients with ADPKD also suffer from type 2 diabetes, a metabolic disorder characterized by high blood glucose levels and insulin resistance.
The problem is that the standard Western diet is high in carbohydrates, which provides your body with a continuous supply of glucose. This can be problematic for those who are trying to reduce the negative effects associated with polycystic kidney disease, such as high blood pressure and fatigue.
In contrast, the ketogenic diet reduces blood glucose levels by restricting carbs to 50 grams or less per day and increasing dietary fats. Carb restriction forces your body to burn its stored fat and produce ketone bodies—like beta-hydroxybutyrate (BHB) and acetoacetate (AcAc)—that now serve as an alternative fuel source to glucose.