High-protein diets

increase the risk of developing kidney disease

High-protein diets, like the popular http://paleocereal.blogspot.com/Dr. Dukan diet, increase the long-term risk of developing kidney disease and have a negative effect on renal urinary and morphological markers. What's more, they may promote serious pathologies like nephrolithiasis calcium kidney stones because they drastically reduce urinary citrate an inhibitor of calcium salt crystallization and urinary pH, and increase urinary calcium to compensate for the metabolic acidity caused by excess protein.

University of Granada scientists have proved this in an experiment in rats that examined the effects of a high-protein diet on renal urinary, plasma and morphological parameters.

The researchers studied 20 Wistar rats, divided into two groups of 10. The first group were fed a high-protein diet of commercial hydrolysed protein supplements with a 45% protein level. The control group were fed a normal protein diet. The experiment lasted 12 weeks, which is the equivalent of 9 years in human terms.

10 per cent weight lossThe results showed that the rats on a high-protein diet lost up to 10% of their body weight over the 12 weeks with no improvement in their plasma lipid profile. Moreover, urinary citrate in these rats was 88% lower and urinary pH was 15% more acidic. In the animals fed a high-protein diet, kidney weight increased by 22%, glomerular area the network of capillaries that filter blood in the kidneys by 13%, and the mesangium a collagen structure surrounded by these capillaries by 32%.

The results of this study lead the principle author, Dr Virginia A. Aparicio of the University of Granada Department of Physiology, to stress the need to closely monitor anyone on a high-protein diet. The Dukan diet, and others like it, can have serious long-term adverse effects on their health.

She warns that the negative effects of high-protein diets on the kidney also depend on the presence of other nutrients in the diet.

Explore further:Diabetics benefit from high-protein diets without risk, study findsMore information: High-protein diets and renal status in rats V. A. Aparicio, E. Nebot, R. García-del Moral, M. Machado-Vílchez, J. M. Porres, C. Sánchez and P. Aranda Nutrición Hospitalaria.