Kidney Function and The Paleo Diet

Professor Cordain,

I just finished The Paleo Answer and I’m eager to start dieting. However, I’m a bit concerned about the diet’s impact on my one kidney. I lost one kidney in a snowboarding accident about 15 years ago. I’ve been taught that for the kidney, proteins are bad and carbs are good. Having read your book, I’m beginning to doubt this.

My main question: Is the Paleo Diet good for kidney function? Subsequently, should I tailor the diet to include less protein and more carbs? I have no renal issues and annual checkups show 100% functionality. Weight loss and better blood chemistry is my goal, but kidney function is most important.

I appreciate any input and any interesting studies. I’d love to read them.

Thanks,

Matthew

Dr. Cordain’s Response:

Hi Matthew,

There are at least two randomized controlled trials in healthy normals showing that high protein diets don’t adversely affect kidney function. ^{1, 2} The data shows that the kidney responds like muscle tissue to “increased loading” – it improves function by increasing the amount of protein by-products that it can eliminate. So, increasing dietary protein does not cause albumin to appear in the urine and the glomerular filtration rate (GFR), the rate the kidney filters the blood, when normalized by increased kidney volume remains normal and healthy. Nevertheless, I suggest that you check in with your nephrologist before and a week or two after you begin The Paleo Diet.

Cordially,

Loren Cordain, Ph.D., Professor Emeritus

REFERENCES:

1. Skov AR, Toubro S, Bülow J, Krabbe K, Parving HH, Astrup A. Changes in renal function during weight loss induced by high vs low-protein low-fat diets in overweight subjects. Int J Obes Relat Metab Disord. 1999 Nov;23(11):1170-7

2. Friedman AN et al. Comparative effects of low-carbohydrate high-protein versus low-fat diets on the kidney. Clin J Am Soc Nephrol 2012;7: 1103-1111