Protein intake and kidney function in humans: its effect on 'normal aging'.

The effect of dietary protein on kidney function expressed by creatinine clearance was studied in healthy subjects following a "normal" unrestricted protein diet and compared with a group of vegetarians maintained on a long-term low-protein diet. Both groups had similar kidney function and displayed the same rate of progressive deterioration in renal function with age. These results suggest that, in contrast with the important therapeutic effect of low-protein intake on the progressive deterioration of kidney function in diseased kidneys, such a diet does not significantly affect kidney function with "normal aging" in healthy subjects.