Autosomal-dominant polycystic kidney disease is the most common genetic disease that affects the kidneys. Animal models hinted that a keto diet may slow down kidney cyst progression. To determine if this holds true in actual people, this question was addressed by the KETO-ADPKD study, which was conducted at the University Hospital of Cologne, Germany. This clinical study which included a 90-day trial period, was aimed to provide insights into the impact of a plant-focused keto diet compared to normal diet on renal cyst growth and kidney function in patients with polycystic kidney disease. Let's explore the key findings!
First, what is Ketogenic Diet?
This special diet induces a metabolic change where ketones are used as a primary energy source by the body. It has some potential benefits, especially in those affected by diabetes, as it may lower blood glucose levels and reduce insulin resistance. This may also help with weight loss in select patients. It has some adverse effects of which we will learn in more detail later in this article.
Essentially, to achieve this metabolic shift, carbohydrate intake (sugar) is drastically decreased while the protein intake and fat consumption is significantly increased. This means steering clear of yummy bread and desserts, and opting for sources of healthy fats like olive oil and fatty fish instead.
How easy is it to stick to it?
The most important part of any special dietary pattern is being able to sustain the change over time with a focus on maintaining the quality of life. It turns out that sticking to a plant-focused ketogenic nutrition style can be challenging for many people, especially when faced with everyday situations like dining out at restaurants.
The KETO-ADPKD study explored the feasibility of following a keto diet measuring factors such as ketone bodies in the blood and breath, as well as using questionnaires to assess adherence. Results showed that while the diet was feasible over a three-month period, there were obstacles to overcome in everyday life. Planning ahead for meals, especially when eating out, was identified as one of the challenges in maintaining this dietary regimen.
Can a Ketogenic Approach Slow Down Kidney Cyst Growth?
Larger studies are still needed to determine the potential impact of a plant-focused ketogenic diet on polycystic kidney disease (PKD). Typically, polycystic kidneys continue to enlarge over time. In this three months' study that compared a control group on a standard diet with participants on a ketogenic diet, a slight decrease in kidney volume was observed in the latter group. However, there was no statistical significance in between the groups and it is still uncertain whether the ketogenic metabolism truly has an effect on kidney cyst growth or renal function. More clinical trials are needed to provide a clear answer to this question.
Can This Special Diet Benefit or Harm Kidney Function in Patients with ADPKD?
The effects of a ketogenic diet on kidney health, particularly in individuals with ADPKD, are still being studied. This research study demonstrated that kidney function actually increased over a three-month period on a ketogenic diet, which was a significant finding. However, the long-term effects of this dietary pattern on the glomerular filtration rate (GFR) in people with kidney disease are not yet known. More studies are needed to fully understand the effects on polycystic kidney disease progression.
What are the downsides of this special dietary approach?
When considering adopting a ketogenic diet, it's important to be aware of the potential downsides on a patient's metabolic health. Some patients may experience an increase in cholesterol levels along with increased animal protein, fat intake and weight loss. In clinical practice, this is important to consider, especially if the patient has other cardiovascular risk factors. Another known side effect is the "keto flu" which can occur in the first few days of the dietary change, resulting in symptoms like headaches and fatigue, symptoms that may also appear in individuals not affected by PKD which typically subside after a few days.
Is a Ketogenic Diet Safe for ADPKD Patients?
Probably, however we do not have sufficient data to confidently make a recommendation for following a ketogenic diet in patients who suffer from adult-polycystic kidney disease. Patients should consult their physician and dietician before making any dietary changes, taking into account their overall health and disease state.
Take Away Points:
We do not know yet if ketogenic diet has positive effects on kidney function or if it lowers the risk of kidney failure in patients affected by ADPKD (autosomal-dominant polycystic kidney disease).
The following dietary interventions were proven to slow down the loss of kidney function in ADPKD (autosomal-dominant polycystic kidney disease) patients:
Moderate salt restriction (2.3-3g/day) lowers blood pressure but also helps lower the levels of a hormone known as ADH (anti-diuretic hormone). This hormone, when in excess, is known to promote cysts growth in affected patients.
Drinking water in sufficient amounts (~ 3000 ccs/ day in patients without advanced chronic kidney disease) also suppresses the anti-diuretic hormone (ADH) production, which is beneficial in ADPKD.
Moderate protein restriction (not less than 0.8 gm/ kg) in patients with evidence of protein loss in the urine helps slow the progression of chronic kidney disease. In those without proteinuria, dietary protein restriction is not necessary. As a special note, soy protein contains phytoestrogen that can stimulate estrogen receptor and the growth of liver cysts. Avoiding excess soy protein intake is recommended in ADPKD (autosomal-dominant polycystic kidney disease) as patients with kidney cysts may have liver cysts as well.
Ensuring your safety is our top priority. We strongly advise you to seek advice from your doctor before making any changes to your diet.