Genetically linked but common polycystic kidney disease (PKD) has long been perceived to be progressive and irreversible, sentencing patients to a slow and often painful decline as fluid filled cysts develop in the kidneys, grow and multiply and disrupt the organ from functioning properly. Once the kidneys fail, PKD patients often need dialysis or have to undergo a kidney transplant. To escalate issue, a host of other PKD-related conditions and complications add to the patients’ health burden, including high blood pressure vascular problems and cysts in the liver. Then there is high medical cost involved and also a reduced quality of life. Each year, about 9.2 million people globally are diagnosed with polycystic kidney disease (PKD). There is only one drug to date that is able to only slow the progression but not stop it and it does not work in about 60% of the cases.
A recent study by the University of California, Santa Barbara has discovered that simple manner to treating polycystic kidney disease is simply through diet.
Biochemist Thomas Weimbs, co-author commented, “It’s surprisingly effective, much more effective than any drug treatment that we’ve tested, and it involves just a diet and fasting. There’s a way of avoiding the development of the cysts through dietary interventions that lead to ketosis.”
The research team found in their previous studies that reducing food intake in animal models slowed the growth of polycystic kidneys; but at the time, they did not know why. In their new paper, the scientists have identified the specific metabolic process responsible for slowing the progress of the disease.
Ketosis, the underlying metabolic state of popular diets such as the ketogenic diet, and, to a lesser extent, time-restricted feeding (a form of intermittent fasting), has been shown in the studies to stall and even reverse polycystic kidney disease.
The study showed that the cysts appear to be largely glucose-dependent. In people with the predisposition toward PKD, the continuous supply of sugar in the high-carbohydrate, high-sugar diets of modern culture serve to feed the growth and development of the fluid-filled sacs.
Ketosis is a natural response to fasting. When we fast, our carbohydrate reserves are very quickly used up. In order to not die, our bodies switch over to a different energy source and that comes from our fat reserves. The fat reserves are broken down into fatty acids and ketones which then take the place of glucose in providing energy to the body. The Weimbs team found that the presence of ketones in the blood stream in particular inhibits the growth of the kidney cysts. And with a steady supply, ketones actually acted to reverse the condition in their animal studies.
The issue with typical Western diets is that one almost never go into ketosis: people eat high-carb, high-sugar foods almost continuously throughout the day, securing for themselves a continuous supply of glucose. In the ketogenic diet, the body’s typical “go-to” source of energy glucose is taken away as ketogenic dieters focus on non-carbohydrate foods, eventually forcing their bodies to mimic the fasting response. Time-restricted feeders, meanwhile, reach that state by limiting the window of time they eat to a small part of the day, leaving the remaining 16-20 hours of their day for the body to use up the carbs and sugars and switch over into ketosis.
The compounds Ketones are actually a class of three different naturally occurring molecules. Of particular interest and effectiveness is one called BHB (beta hydroxybutyrate), which has been shown “to affect numerous signaling pathways that are implicated in polycystic kidney disease.” according to the study. The team found that by just feeding that ketone to animal models with PKD, they were able to create the beneficial effects of ketosis, no special diet restriction needed.
Weimbs commented, “Which makes this really amazing,” On top of a normal high-carb diet, which they can eat all day long, if we give them BHB, they’re fine.” After five weeks of treatment with BHB in the drinking water, rat polycystic kidneys were “nearly indistinguishable” from normal ones.
Postdoctoral researcher Dr Jacob Torres and coauthor further commented, ”The impact of this research has huge implications on the field of polycystic kidney disease (PKD). It provides a framework for understanding the pathology of PKD from a metabolic viewpoint and adds another disease to the list that a ketogenic diet can be used to treat. Our discovery also has implications for understanding cellular metabolism at a fundamental level as we learn more about what has gone wrong in our disease models. I am really looking forward to the future of research in this field as we explore this new space and uncover even more about what is really going on in PKD.”
Weimbs said, “It’s quite possible to reach ketosis just by avoiding carbs or by fasting for a period of time. It’s a very natural way to have your own body produce BHB. So something like a time-restricted diet is feasible.”
But the key to success with diet-related issues is consistency. Ask virtually any dieter and they’ll tell you that staying on track is the difficult part.
For those with polycystic kidneys who could use an assist with ketosis, whether or not they need to lose weight or wish to change their diets, the Weimbs lab is developing a dietary supplement to add BHB to their regular intake. This patent-pending nutritional supplement would be similar to commercially available ketone products being offered as energy boosters, but formulated specifically for supporting kidney health.
Weimbs further added “We want to make sure we don’t put anything harmful into the bodies of people with potentially compromised kidney function. And some of the ketone products already out there are high in potassium and other ingredients that could be detrimental.”
The supplement being developed is combined with another nutrient the Weimbs Lab has recently shown to inhibit cyst formation in PKD by a completely different mechanism from BHB, thereby approaching the problem from two directions. While not a drug and therefore less expensive and essentially free of serious side effects the supplement is nevertheless intended for use by those under medical supervision. Members of the Weimbs team are planning to conduct a clinical trial to test their supplement mixture in people with polycystic kidney disease. PKD. Assuming all goes well, they are planning to launch a company to make it available.
The product is expected to be ready before the end of 2019 and the team is planning clinical trials as early as January 2020 before the product is made commercially available.