I am struck by the prevalence of kidney disease and the deep connection it has with nutrition. More than one in 10 Americans currently have chronic kidney disease, and the number is increasing¹.

The kidney is the organ that has been perhaps most linked to nutrition for over one hundred years, even among the establishment physician crowd. In 1836, a series of case reports from Dr. Bright, published in Guy’s Hospital Reports, established the idea that those who died from kidney disease had protein in their urine². Over the next 100 years, it was established that when you reduced the kidney’s functional capacity by surgery (in experimental animal studies) the amount of protein consumed dramatically affected the growth and mass of the remaining functional kidney³. It was known as standard treatment in 1948 to restrict protein intake in kidney disease⁴, and, by 1981, a seminal paper⁵ established that there were damaging structural changes in the kidney that occurred as a result of excessive protein intake. (The above statements apply to those people with kidney disease that hasn’t yet progressed to cessation of function, or dialysis. For those on dialysis, protein and nutritional recommendations are different.)

The major kidney societies of the world still recommend less protein intake for pre-dialysis kidney disease than what is widely acknowledged to be the excess protein consumption of the modern western diet.^6,7 Further, there is now evidence that there is a difference between plant and animal protein in kidney health: plant proteins may be more protective and animal proteins may be more damaging^8,9. While there is always more research to be done to establish the details of the dietary effect, the results are consistent with results found for the whole web of associated diseases and conditions.

References

1. Coresh J, Selvin E, Stevens LA, et al. Prevalence of chronic kidney disease in the United States. JAMA : the journal of the American Medical Association 2007;298:2038-47.
2. Bright R. Cases and observations, illustrative of renal disease accompanied by the secretion of albuminous urine. Guy’s Hospital Reports 1836;1:338-400.
3. Mackay EM, MacKay LL, Addis T. Factors which determine renal weight. V. The protein intake. American journal of physiology 1928;86:459-65.
4. Addis T. Glomerular nephritis, diagnosis and treatment. New York,: Macmillan Co.; 1948.
5. Hostetter TH, Olson JL, Rennke HG, Venkatachalam MA, Brenner BM. Hyperfiltration in remnant nephrons: a potentially adverse response to renal ablation. J Am Soc Nephrol 2001;12:1315-25.
6. NKF KDOQI GUIDELINES. Accessed online 8/7/2013 at (link)
7. Nutrition in CKD. Renal Association. Accessed online 8/7/2013 at (link)
8. Williams AJ, Baker F, Walls J. Effect of varying quantity and quality of dietary protein intake in experimental renal disease in rats. Nephron 1987;46:83-90.
9. Bernstein AM, Treyzon L, Li Z. Are high-protein, vegetable-based diets safe for kidney function? A review of the literature. Journal of the American Dietetic Association 2007;107:644-50.