Researchers at the University of Cologne explored how dietary composition affects kidney function in people with polycystic kidney disease. The study, published in Cell Reports Medicine, examined whether reducing sugar while increasing fat intake could influence disease outcomes. The aim was to see if a metabolic shift could support kidney health in this chronic condition.
Sixty-six participants completed the three‑month trial. They were randomly assigned to one of three groups: a ketogenic diet group, an intermittent fasting group that practiced a three‑day water fast once a month, and a control group receiving standard dietary guidance. This design allowed investigators to compare a fat‑heavy, low‑carbohydrate approach with fasting and with typical recommendations commonly given to patients.
The ketogenic diet group showed measurable improvements in kidney function. Blood tests supported these findings, as the estimated glomerular filtration rate which tended to decline in the other groups during the study rose in the ketogenic cohort. In addition to kidney metrics, weight changes were observed across the groups: participants on the ketogenic diet and those undergoing water fasting lost weight, while the control group experienced a slight weight increase.
The rationale behind the ketogenic approach is to boost the production of ketone bodies by the body. This metabolic shift is achieved by lowering carbohydrate intake, especially sugars and baked goods, while increasing the consumption of fats from sources like avocados and fatty fish. In this trial, a high tolerance to the diet was reported by most participants in the ketogenic group and a majority in the fasting group, suggesting the regimen was manageable for many with careful plan and supervision.
While the results are promising, researchers cautioned that the evidence is not yet strong enough to broadly recommend a ketogenic diet for all patients with polycystic kidney disease. The study authors emphasized the need for larger trials with more participants to confirm the findings and to assess long‑term safety and efficacy.
Hereditary polycystic kidney disease accounts for about 10 percent of kidney failure cases and gradually impairs the kidneys’ filtration capacity. The disease typically progresses over time and in advanced stages can lead to complications that require dialysis or kidney transplantation. Ongoing research continues to investigate how diet, genetics, and other factors influence disease trajectory and how best to support kidney function in affected individuals.
Earlier work in this area has explored several approaches, including the potential of pharmacological strategies to reduce the risk of kidney and heart damage in chronic kidney disease. While those efforts show promise, the current trial adds to a growing body of evidence that dietary patterns can play a meaningful role in managing kidney health in polycystic disease.