The Kidney plays a major role in the excretion of metabolic wastes, the regulation of body fluid, and the maintenance of electrolyte balance. The kidneys synthesize and release hormones, and convert vitamin D3 to its active 1, 25- dihydroxy vitamin D3 form.

Renal disease is an important cause of morbidity and mortality in industrial and post-industrial societies. Kidneys when healthy regulate the amount of fluid, potassium and sodium in the body. Kidneys also remove waste products produced from the food we eat and drink. When kidneys do not function properly, these substances buildup in the blood and cause illness. The different problems associated with kidney diseases are:

Proteinuria: Proteinuria is the spillage of proteins and other important blood constituents in the urine, and it is present in a good number of patients with chronic renal disease. Presence of proteinuria, especially if higher than 3 grams per day, leads to a long list of medical complications and also hastens the progression toward end stage renal disease.

Blood vessel disease: Patients with chronic renal failure have a very high, well-defined risk of premature blood vessel disease. Studies have shown that high blood levels of homocysteine (a by-product of the amino acid methionine) increase the risk of blood vessel disease in renal failure patients, independent of the other known risk factors such as diabetes, hypertension, lipid abnormalities and smoking. The homocysteine blood levels increase in proportion to the dietary intake of methionine. In patients with chronic renal disease the homocysteine levels increase more for a given methionine load than they do in normal individuals.

Dialysis is a method of removing toxic substances (impurities or wastes) from the blood when the kidneys are unable to do so.

Proteins are used by the body to help tissue growth and for repair. Urea is the waste product produced from the protein we eat. Urea builds up when the kidneys do not function properly. Urea buildup in the body can cause nausea, vomiting and weakness. Dialysis treatments can remove urea, which helps prevent these symptoms. This process unfortunately removes other vital proteins from the blood that our body requires. If enough protein is not provided through diet, it will lead to breakdown of muscle proteins.

Protein is lost during dialysis, particularly albumin, being the most abundant protein component in blood.  The dialysis-associated albumin loss causes a reduction in serum albumin, particularly if the serum albumin level of the patient remains in the lower normal range. This will cause protein malnutrition. In people undergoing peritoneal dialysis, appetite is generally poor. This is because of the kidney’s inability to generate buffers, and to eliminate dietary acids leading to accumulation of acids that suppress the appetite.  The extra fluid in the abdomen also makes them feel full. This poses a challenge for nutritionists who care for patients with renal insufficiency, since animal proteins are high in methionine and the renal protein-restricted diets, which usually contain animal proteins, provide a relatively large amount of methionine.

People undergoing dialysis need a special diet. Subjects fed 90 grams of meat protein daily showed a significantly greater increase in GFR (stress on the kidney) than was seen for subjects fed 90 grams of casein. Rats fed with casein showed a lowered rate of decrease in renal function (Jones MG, 1987)

Studies are carried out in metabolic units to determine the level of dietary protein required for people treated with maintenance dialysis. Studies by Blumenkrantz et al. and Bergstrom et al. in peritoneal dialysis patients demonstrated that protein requirement is more for the body than intake with diets providing less than 1.2 g protein/kilogram of body weight per day. This requirement is higher than that recommended for healthy subjects, which is about 0.8 g/kg per day.

This higher protein requirement is due to loss of protein and amino acids into dialyzing fluid. Several studies report losses of approximately 1 to 2 g of protein into dialyzing fluid with conventional dialyzing units. Losses of amino acids into dialyzing fluid average 6 to 12 g per treatment. Losses of proteins into dialyzing fluid are higher with peritoneal dialysis compared to hemodialysis, and are reported to be approximately 5 to 15 g/day, and protein loss increases with episodes of inflammation of peritoneum caused due to dialysis. During this inflammation, the blood vessels expand and the peritoneal membrane becomes permeable for bigger molecules like protein. Hence there will be protein loss. Dialysis patients with diets providing less than 1.2 g protein/kilogram of body weight per day showed malnutrition. These data lead to the recommendation that dietary protein intake for patients treated with peritoneal dialysis should be approximately 1.3 g protein/kilogram of body weight per day, to be certain that all patients receive adequate protein intake (Blumenkrantz et al , 1982 and Bergstorm et al, 1993).

Due to the loss of proteins, dialytic patients may suffer from malnutrition. The use of casein increases serum albumin concentration. On reaching stomach, the casein reacts with the stomach acids forming clots that provide a sustained slow release of amino acids into the blood stream. This will surely help in meeting the demand of the body for an increased supply of amino acids, for providing energy and promoting protein synthesis.

Whey protein contains an ample supply of the amino acid cysteine. Whey protein contains all the essential amino acids in higher concentration than all vegetable proteins. The amino acids found in whey are efficiently absorbed and utilized.

Renal failure patients develop high blood pressure. Blood pressure control is very important to slowing progression of renal failure. Casokinins and lactokinins are two ACE inhibitory peptides present in Casein and whey protein. They have been found to be very effective in lowering blood pressure.

Hence it is recommended that casein and whey proteins are used for decreasing the stress to kidneys, reducing the subsequent complications, and restoring the protein loss during dialysis.

One of the benefits of using whey as a protein supplement is that till date no severe adverse reactions have been noted following administration of whey protein products, although some patients note minor gastrointestinal disturbances.

About Protica

Founded in 2001, Protica, Inc. is a nutritional research firm with offices in Lafayette Hill and Conshohocken, Pennsylvania. Protica manufactures capsulized foods, including Profect, a compact, hypoallergenic, ready-to-drink protein beverage containing zero carbohydrates and zero fat. Information on Protica is available at http://www.protica.com 

You can also learn about Profect at http://www.profect.com 

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