In rats at least it seem to be true. That was the cautionary news from a piece of research published in the Spanish journal Nutricion Hospitalaria.
Rats were split into two groups and fed either a normal or a high protein diet for 12 weeks. At the end of the diet, the rats on the high protein diet had 88% lower citrate levels in the urine and the pH was more acidic. This can increase the chances of calcium kidney stones as citrate is an inhibitor of calcium salt crystallisation.
It’s not all bad news through, they did lose 10% of their body weight during the diet and the effect of protein on the body can be offset by eating fruit and vegetables. It is thought the high level of magnesium and potassium are to thank for this. Potassium, for example, stimulates the urinary excretion of citrate which could help to “flush the system”.
Time to stock up on bananas methinks.