.jpg)
High-protein diets—commonly known as "Stone Age diets" or the Paleolithic diet—are popular and include the consumption of fruits, vegetables, lean meats, fish, eggs, nuts, and seeds. Although these diets are effective for weight management and diabetes control, they are not without risks.
Excess protein leads to a significant increase in the production of ammonium, placing stress on the liver. Ammonium overload can cause neurological disturbances and, in severe cases, coma.
Researchers at the University of Geneva in Switzerland used mice to study the effects of such diets. The findings, published in the Journal of Biological Chemistry, suggest caution when adopting these diets.
Weight Loss to Control Diabetes
Type 2 diabetes is a metabolic disease that is steadily increasing. Due to sedentary lifestyles and dietary factors, the weakened pancreas struggles to regulate blood sugar levels. While current treatments help manage the disease's progression, they do not cure it. Weight loss is often a key component of treatment.
Pierre Maechler, a professor in the Department of Cell Physiology and Metabolism at the University of Geneva Faculty of Medicine who led the study, explained: "High-protein diets—both animal and plant-based—commonly referred to as Stone Age diets, can be used to stabilize type 2 diabetes and regulate weight."
This diet is inspired by meat-based eating patterns from pre-agricultural times. But what effect does it have on the body? Is it truly healthy? That’s what the researchers sought to find out.
Liver Under Pressure
Ammonium is a natural byproduct of protein breakdown. It is eliminated by the liver through an enzyme called glutamate dehydrogenase. Under protein overload, this enzyme comes under strain. To study the effects of high-protein diets, Maechler’s team fed both healthy mice and genetically modified mice lacking glutamate dehydrogenase a diet with protein levels mimicking the Stone Age diet.
The scientists observed that in healthy mice, although ammonium production increased due to excess protein, the liver managed to process the surplus thanks to the action of glutamate dehydrogenase, which neutralizes the ammonium before it causes harm.
Carolina Luczkowska, a former PhD student in the Department of Cell Physiology and Metabolism at the University of Geneva and the lead researcher in the study, explained: “In mice lacking glutamate dehydrogenase, the liver cannot eliminate the toxic ammonium excess derived from proteins. You don't have to wait weeks or months—just a few days of dietary change is enough to observe major consequences.”
These findings indicate that when glutamate dehydrogenase is impaired, high-protein diets can cause dangerous ammonium build-up. This excess, when not cleared by the liver, may lead to serious complications, especially neurological ones.
Pierre Maechler concluded, as reported by EurekAlert: “It is important to be well-informed before starting a high-protein diet.”
Source: Al Jazeera