Is limiting protein intake for kidney transplant patients healthy?


Conventional knowledge holds that people with renal illness should eat a low-protein diet. Researchers from Osaka Metropolitan University have recently shown that this may not always be the case by examining the connection between protein consumption and skeletal muscle mass in kidney transplant recipients. Their findings were published in Clinical Nutrition.

Chronic inflammation, hypercatabolism, decreased food intake, and decreased physical activity—all of which are linked to altered kidney function—have been demonstrated to produce sarcopenia in chronic kidney disease patients. A successful kidney transplant can improve or correct many of these physiological and metabolic problems. Therefore, after a kidney transplant, those who received one develop skeletal muscle mass. It is generally accepted that people with chronic renal disease, including kidney transplant recipients, should limit their protein consumption in order to protect their kidneys since too much protein inhibits kidney function. On the other side, severe protein restriction has been associated with progressive sarcopenia and a bad prognosis.

Since diet and exercise therapy are advised to treat sarcopenia, protein consumption is hypothesised to be related to the restoration of skeletal muscle mass following kidney donation. The relationship between skeletal muscle mass and protein intake in kidney transplant recipients has, however, barely been studied.

To address this gap, a research team at the Department of Urology, Graduate School of Medicine, Osaka Metropolitan University, led by Drs. Akihiro Kosoku, Tomoaki Iwai, and Professor Junji Uchida, examined the connection between protein intake and changes in skeletal muscle mass, as determined by bioelectrical impedance analysis (as estimated from urine collected from 64 kidney transplant recipients 12 months after transplantation). The results showed that protein intake during this time was positively linked with changes in skeletal muscle mass, and that a protein deficit led to a loss in muscle mass.

According to Drs. Iwai and Kosoku, more research is required to determine the ideal protein diet for kidney transplant recipients in order to avoid sarcopenia or loss of renal function. We anticipate that nutritional counselling will increase prognosis and increase protein consumption.