Changing patterns of medical practice: protein restriction for chronic renal failure.

The use of dietary protein restriction for renal failure has fluctuated during the past 125 years. These fluctuations reflect not only the state of medical knowledge but also social, economic, and cultural factors. Factors inhibiting use of dietary treatment have been its status as an aspect of hygiene rather than as active therapy; the opinions of dominant practitioners and scientists around midcentury, including a presumption that renal adaptation to a high-protein diet must be appropriate; fear of malnutrition and a cultural belief in the virtue of dietary protein; unwillingness by physicians and patients to restrict consumption or lifestyle; and professional identification with the technologies of dialysis and renal transplantation. Factors promoting dietary treatment have been rediscovery of previous work on protein-induced renal injury; a sense that homeostatic compensations could have adverse consequences; federal incentives to curb consumption of scarce resources such as renal dialysis; and the integration of research on, and therapeutic use of diet into scientific medicine. A large ongoing study of dietary protein restriction to limit renal injury will add to our knowledge of this treatment; its application will surely be informed by social and cultural considerations.