Diet changes can improve diabetic kidney function

In type 2 diabetes patients with macroalbuminuria - excessive urine levels of a protein called albumin - replacing red meat with chicken in the diet reduces macroalbuminuria, as well as microalbuminuria. Albumin is normally found in the blood, but indicates impaired kidney function when it appears in the urine.

Withdrawal of red meat from the diet "may represent an additional therapeutic tool in the management of this severe complication of diabetes," Dr. Jorge L. Gross told Reuters Health.

Previously, Gross and colleagues from Universidade Federal do Rio Grande do Sul in Porto Alegre, Brazil reported that replacing red meat with chicken reduced the urinary albumin excretion rate by 46 percent and also improved the serum cholesterol levels in a group of type 2 diabetic patients with microalbuminuria.

In their latest study, the researchers had 17 type 2 diabetic patients with macroalbuminuria follow their usual diet; a chicken diet (red meat replaced with chicken); or a low-protein vegetarian diet that included milk and milk products. Each participant followed each diet, in a random order, for four weeks, taking a four-week break in between the diets.

The urinary albumin excretion rate was significantly lower after the chicken diet and the low-protein diet compared with the usual diet, the team reports in the American Journal of Clinical Nutrition.

Three subjects (17.6 percent) after the chicken diet and eight (47.1 percent) after the low-protein diet had macroalbuminuria reduced to microalbuminuria.

The diet-induced reduction in urinary albumin in patients who already had advanced diabetic kidney disease was "one of the most important findings," Gross noted.

The chicken and low-protein diets also improved cholesterol and increased blood levels of polyunsaturated fatty acid, one of the "good" fats. This shows that eliminating red meat from the diet may lower the increased risk of death from cardiovascular disease that often occurs in the these patients, Gross said.

Levels of blood sugar and blood pressure were largely unaffected by the diets. While the patients' weight was not altered by the usual diet or the chicken diet, it was lower after the low-protein diet.

SOURCE: American Journal of Clinical Nutrition, May 2006.