Observational data from epidemiological studies provide
evidence that dietary protein intake may be related to the
progression of renal disease [52]. In the Nurses' Health
Study, protein intake, assessed with a semi-quantitative
food frequency questionnaire, was compared to the
change in estimated GFR over an 11-year span in individuals
with pre-existing renal disease [53]. Regression analysis
showed an association between increased
consumption of animal protein and a decline in renal
function suggesting that high total protein intake may
accelerate renal disease leading to a progressive loss of
renal capacity. However, no association between protein
intake and change in GFR was found in a different cohort
of 1,135 women with normal renal function (Figure 1.).
The latter finding led the authors to conclude that there
were no adverse effects of high protein intakes on kidney
function in healthy women with normal renal status.